Publications

@article{nokey,

title = {Postsynthetic Transformation of Imine- into Nitrone-Linked Covalent Organic Frameworks for Atmospheric Water Harvesting at Decreased Humidity},

author = {L Grunenberg and G Savasci and S T Emmerling and F Heck and S Bette and A Cima Bergesch and C Ochsenfeld and B V Lotsch},

url = {https://doi.org/10.1021/jacs.3c02572},

doi = {10.1021/jacs.3c02572},

issn = {0002-7863},

year  = {2023},

date = {2023-05-25},

journal = {Journal of the American Chemical Society},

volume = {145},

number = {24},

pages = {13241-13248},

abstract = {Herein, we report a facile postsynthetic linkage conversion method giving synthetic access to nitrone-linked covalent organic frameworks (COFs) from imine- and amine-linked COFs. The new two-dimensional (2D) nitrone-linked covalent organic frameworks, NO-PI-3-COF and NO-TTI-COF, are obtained with high crystallinity and large surface areas. Nitrone-modified pore channels induce condensation of water vapor at 20% lower humidity compared to their amine- or imine-linked precursor COFs. Thus, the topochemical transformation to nitrone linkages constitutes an attractive approach to postsynthetically fine-tune water adsorption properties in framework materials.},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Investigating Plasmonic Catalysis Kinetics on Hot-Spot Engineered Nanoantennae},

author = {L Nan and J Gir\'{a}ldez-Mart\'{i}nez and A Stefancu and L Zhu and M Liu and A O Govorov and L V Besteiro and E Cort\'{e}s},

url = {https://doi.org/10.1021/acs.nanolett.3c00219},

doi = {10.1021/acs.nanolett.3c00219},

issn = {1530-6984},

year  = {2023},

date = {2023-03-31},

journal = {Nano Letters},

abstract = {Strong hot-spots can facilitate photocatalytic reactions potentially providing effective solar-to-chemical energy conversion pathways. Although it is well-known that the local electromagnetic field in plasmonic nanocavities increases as the cavity size reduces, the influence of hot-spots on photocatalytic reactions remains elusive. Herein, we explored hot-spot dependent catalytic behaviors on a highly controlled platform with varying interparticle distances. Plasmon-meditated dehalogenation of 4-iodothiophenol was employed to observe time-resolved catalytic behaviors via in situ surface-enhanced Raman spectroscopy on dimers with 5, 10, 20, and 30 nm interparticle distances. As a result, we show that by reducing the gap from 20 to 10 nm, the reaction rate can be sped up more than 2 times. Further reduction in the interparticle distance did not improve reaction rate significantly although the maximum local-field was ∼2.3-fold stronger. Our combined experimental and theoretical study provides valuable insights in designing novel plasmonic photocatalytic platforms.},

keywords = {Molecularly-Functionalized, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Transient absorption spectroscopy based on uncompressed hollow core fiber white light proves pre-association between a radical ion photocatalyst and substrate},

author = {A Kumar and P Malevich and L Mewes and S Wu and J P Barham and J Hauer},

url = {https://aip.scitation.org/doi/abs/10.1063/5.0142225},

doi = {10.1063/5.0142225},

year  = {2023},

date = {2023-03-24},

journal = {The Journal of Chemical Physics},

volume = {158},

number = {14},

pages = {144201},

abstract = {We present a hollow-core fiber (HCF) based transient absorption experiment, with capabilities beyond common titanium:sapphire based setups. By spectral filtering of the HCF spectrum, we provide pump pulses centered at 425 nm with several hundred nJ of pulse energy at the sample position. By employing the red edge of the HCF output for seeding CaF2, we obtain smooth probing spectra in the range between 320 and 900 nm. We demonstrate the capabilities of our experiment by following the ultrafast relaxation dynamics of a radical cationic photocatalyst to prove its pre-association with an arene substrate, a phenomenon that was not detectable previously by steady-state spectroscopic techniques. The detected preassembly rationalizes the successful participation of radical ionic photocatalysts in single electron transfer reactions, a notion that has been subject to controversy in recent years.},

keywords = {Molecularly-Functionalized, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Nanomechanics with plasmonic nanoantennas: ultrafast and local exchange between electromagnetic and mechanical energy},

author = {A V Bragas and S A Maier and H D Boggiano and G Grinblat and R Bert\'{e} and L D S Menezes and E Cort\'{e}s},

url = {https://opg.optica.org/josab/abstract.cfm?doi=10.1364/JOSAB.482384},

doi = {https://doi.org/10.1364/JOSAB.482384},

year  = {2023},

date = {2023-03-10},

journal = {J. Opt. Soc. Am. B},

abstract = {Converted into mechanical nanoresonators after optical pulsed excitation and electron decay into coherent acoustic phonons, plasmonic nanoantennas produce a periodic modulation of their optical properties, allowing, in turn, an optical reading of these extremely small movements. In this work we review the physics of these nanoresonators and their acoustic vibrations, whose frequencies are in the range of a few to tens of GHz. The accurate determination of their oscillation frequencies allows them to act as mechanical nanoprobes, measure local mechanical moduli of the environment, and perform high-resolution imaging using phononic reconstruction. Furthermore, the internal and external damping mechanisms which affect the quality factor of the nanoresonator and, in particular, the role of the substrate when the nanoantennas are integrated into platforms and probed individually are also reviewed. Finally, we discuss the all-optical generation of hypersonic surface acoustic waves with nanoantennas and the importance of their manipulation for potential acousto-plasmonic devices operating in the GHz range and the nanoscale.},

keywords = {Molecularly-Functionalized, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Atomically Local Electric Field Induced Interface Water Reorientation for Alkaline Hydrogen Evolution Reaction},

author = {C Cai and K Liu and L Zhang and F Li and Y Tan and P Li and Y Wang and M Wang and Z Feng and D Motta Meira and W Qu and A Stefancu and W Li and H Li and J Fu and H Wang and D Zhang and E Cort\'{e}s and M Liu},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202300873},

doi = {https://doi.org/10.1002/anie.202300873},

issn = {1433-7851},

year  = {2023},

date = {2023-03-08},

journal = {Angewandte Chemie International Edition},

volume = {n/a},

number = {n/a},

pages = {e202300873},

abstract = {Abstract The slow water dissociation process in alkaline electrolyte severely limits the kinetics of HER. The orientation of H2O is well known to affect the dissociation process, but H2O orientation is hard to control because of its random distribution. Herein, an atomically asymmetric local electric field was designed by IrRu dizygotic single-atom sites (IrRu DSACs) to tune the H2O adsorption configuration and orientation, thus optimizing its dissociation process. The electric field intensity of IrRu DSACs is over 4.00×1010 N/C. The ab initio molecular dynamics simulations combined with in situ Raman spectroscopy analysis on the adsorption behavior of H2O show that the M−H bond length (M=active site) is shortened at the interface due to the strong local electric field gradient and the optimized water orientation promotes the dissociation process of interfacial water. This work provides a new way to explore the role of single atomic sites in alkaline hydrogen evolution reaction.},

keywords = {Molecularly-Functionalized, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {On-surface synthesis of enetriynes},

author = {N Cao and B Yang and A Riss and J Rosen and J Bj\"{o}rk and J V Barth},

url = {https://doi.org/10.1038/s41467-023-36828-y},

doi = {10.1038/s41467-023-36828-y},

issn = {2041-1723},

year  = {2023},

date = {2023-03-06},

journal = {Nature Communications},

volume = {14},

number = {1},

pages = {1255},

abstract = {Belonging to the enyne family, enetriynes comprise a distinct electron-rich all-carbon bonding scheme. However, the lack of convenient synthesis protocols limits the associated application potential within, e.g., biochemistry and materials science. Herein we introduce a pathway for highly selective enetriyne formation via tetramerization of terminal alkynes on a Ag(100) surface. Taking advantage of a directing hydroxyl group, we steer molecular assembly and reaction processes on square lattices. Induced by O2 exposure the terminal alkyne moieties deprotonate and organometallic bis-acetylide dimer arrays evolve. Upon subsequent thermal annealing tetrameric enetriyne-bridged compounds are generated in high yield, readily self-assembling into regular networks. We combine high-resolution scanning probe microscopy, X-ray photoelectron spectroscopy and density functional theory calculations to examine the structural features, bonding characteristics and the underlying reaction mechanism. Our study introduces an integrated strategy for the precise fabrication of functional enetriyne species, thus providing access to a distinct class of highly conjugated π-system compounds.},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Thermal site energy fluctuations in photosystem I: new insights from MD/QM/MM calculations},

author = {S Reiter and F L Kiss and J Hauer and R De Vivie-Riedle},

url = {http://dx.doi.org/10.1039/D2SC06160K},

doi = {10.1039/D2SC06160K},

issn = {2041-6520},

year  = {2023},

date = {2023-02-06},

journal = {Chemical Science},

volume = {14},

number = {12},

pages = {3117-3131},

abstract = {Cyanobacterial photosystem I (PSI) is one of the most efficient photosynthetic machineries found in nature. Due to the large scale and complexity of the system, the energy transfer mechanism from the antenna complex to the reaction center is still not fully understood. A central element is the accurate evaluation of the individual chlorophyll excitation energies (site energies). Such an evaluation must include a detailed treatment of site specific environmental influences on structural and electrostatic properties, but also their evolution in the temporal domain, because of the dynamic nature of the energy transfer process. In this work, we calculate the site energies of all 96 chlorophylls in a membrane-embedded model of PSI. The employed hybrid QM/MM approach using the multireference DFT/MRCI method in the QM region allows to obtain accurate site energies under explicit consideration of the natural environment. We identify energy traps and barriers in the antenna complex and discuss their implications for energy transfer to the reaction center. Going beyond previous studies, our model also accounts for the molecular dynamics of the full trimeric PSI complex. Via statistical analysis we show that the thermal fluctuations of single chlorophylls prevent the formation of a single prominent energy funnel within the antenna complex. These findings are also supported by a dipole exciton model. We conclude that energy transfer pathways may form only transiently at physiological temperatures, as thermal fluctuations overcome energy barriers. The set of site energies provided in this work sets the stage for theoretical and experimental studies on the highly efficient energy transfer mechanisms in PSI.},

keywords = {Molecularly-Functionalized, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Highly Efficient Sum-Frequency Generation in Niobium Oxydichloride NbOCl2 Nanosheets},

author = {I Abdelwahab and B Tilmann and X Zhao and I Verzhbitskiy and R Bert\'{e} and G Eda and W L Wilson and G Grinblat and L De S. Menezes and K P Loh and S A Maier},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adom.202202833},

doi = {https://doi.org/10.1002/adom.202202833},

issn = {2195-1071},

year  = {2023},

date = {2023-02-05},

journal = {Advanced Optical Materials},

volume = {11},

number = {7},

pages = {2202833},

abstract = {Abstract Parametric infrared (IR) upconversion is a process in which low-frequency IR photons are upconverted into high-frequency ultraviolet/visible photons through a nonlinear optical process. It is of paramount importance for a wide range of security, material science, and healthcare applications. However, in general, the efficiencies of upconversion processes are typically extremely low for nanometer-scale materials due to the short penetration depth of the excitation fields. Here, parametric IR upconversion processes, including frequency doubling and sum-frequency generation, are studied in layered van der Waals NbOCl2. An upconversion efficiency of up to 0.004% is attained for the NbOCl2 nanosheets, orders of magnitude higher than previously reported values for nonlinear layered materials. The upconverted signal is sensitive to layer numbers, crystal orientation, excitation wavelength, and temperature, and it can be utilized as an optical cross-correlator for ultrashort pulse characterization.},

keywords = {Molecularly-Functionalized, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Interface-Dependent Selectivity in Plasmon-Driven Chemical Reactions},

author = {A Stefancu and J Gargiulo and G Laufersky and B Augui\'{e} and V Chi\c{s} and E C Le Ru and M Liu and N Leopold and E Cort\'{e}s},

url = {https://doi.org/10.1021/acsnano.2c12116},

doi = {10.1021/acsnano.2c12116},

issn = {1936-0851},

year  = {2023},

date = {2023-02-01},

journal = {ACS Nano},

volume = {17},

number = {3},

pages = {3119-3127},

abstract = {Plasmonic nanoparticles can drive chemical reactions powered by sunlight. These processes involve the excitation of surface plasmon resonances (SPR) and the subsequent charge transfer to adsorbed molecular orbitals. Nonetheless, controlling the flow of energy and charge from SPR to adsorbed molecules is still difficult to predict or tune. Here, we show the crucial role of halide ions in modifying the energy landscape of a plasmon-driven chemical reaction by carefully engineering the nanoparticle\textendashmolecule interface. By doing so, the selectivity of plasmon-driven chemical reactions can be controlled, either enhancing or inhibiting the metal\textendashmolecule charge and energy transfer or by regulating the vibrational pumping rate. These results provide an elegant method for controlling the energy flow from plasmonic nanoparticles to adsorbed molecules, in situ, and selectively targeting chemical bonds by changing the chemical nature of the metal\textendashmolecule interface.},

keywords = {Molecularly-Functionalized, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Photocatalytic CO2-to-Syngas Evolution with Molecular Catalyst Metal-Organic Framework Nanozymes},

author = {P M Stanley and A Y Su and V Ramm and P Fink and C Kimna and O Lieleg and M Elsner and J A Lercher and B Rieger and J Warnan and R A Fischer},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adma.202207380},

doi = {https://doi.org/10.1002/adma.202207380},

issn = {0935-9648},

year  = {2023},

date = {2023-02-01},

journal = {Advanced Materials},

volume = {35},

number = {6},

pages = {2207380},

abstract = {Abstract Syngas, a mixture of CO and H2, is a high-priority intermediate for producing several commodity chemicals, e.g., ammonia, methanol, and synthetic hydrocarbon fuels. Accordingly, parallel sunlight-driven catalytic conversion of CO2 and protons to syngas is a key step toward a sustainable energy cycle. State-of-the-art catalytic systems and materials often fall short as application-oriented concurrent CO and H2 evolution requires challenging reaction conditions which can hamper stability, selectivity, and efficiency. Here a light-harvesting metal-organic framework hosting two molecular catalysts is engineered to yield colloidal, water-stable, versatile nanoreactors for photocatalytic syngas generation with highly controllable product ratios. In-depth fluorescence, X-ray, and microscopic studies paired with kinetic analysis show that the host delivers energy efficiently to active sites, conceptually yielding nanozymes. This unlocked sustained CO2 reduction and H2 evolution with benchmark turnover numbers and record incident photon conversions up to 36%, showcasing a highly active and durable all-in-one material toward application in solar energy-driven syngas generation.},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Shrinking gate fluorescence correlation spectroscopy yields equilibrium constants and separates photophysics from structural dynamics},

author = {T Schr\"{o}der and J Bohlen and S E Ochmann and P Sch\"{u}ler and S Krause and D C Lamb and P Tinnefeld},

url = {https://www.pnas.org/doi/abs/10.1073/pnas.2211896120},

doi = {doi:10.1073/pnas.2211896120},

year  = {2023},

date = {2023-01-18},

journal = {Proceedings of the National Academy of Sciences},

volume = {120},

number = {4},

pages = {e2211896120},

abstract = {Fluorescence correlation spectroscopy is a versatile tool for studying fast conformational changes of biomolecules especially when combined with F\"{o}rster resonance energy transfer (FRET). Despite the many methods available for identifying structural dynamics in FRET experiments, the determination of the forward and backward transition rate constants and thereby also the equilibrium constant is difficult when two intensity levels are involved. Here, we combine intensity correlation analysis with fluorescence lifetime information by including only a subset of photons in the autocorrelation analysis based on their arrival time with respect to the excitation pulse (microtime). By fitting the correlation amplitude as a function of microtime gate, the transition rate constants from two fluorescence-intensity level systems and the corresponding equilibrium constants are obtained. This shrinking-gate fluorescence correlation spectroscopy (sg-FCS) approach is demonstrated using simulations and with a DNA origami-based model system in experiments on immobilized and freely diffusing molecules. We further show that sg-FCS can distinguish photophysics from dynamic intensity changes even if a dark quencher, in this case graphene, is involved. Finally, we unravel the mechanism of a FRET-based membrane charge sensor indicating the broad potential of the method. With sg-FCS, we present an algorithm that does not require prior knowledge and is therefore easily implemented when an autocorrelation analysis is carried out on time-correlated single-photon data.},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {The neglected influence of zinc oxide light-soaking on stability measurements of inverted organic solar cells},

author = {M G\"{u}nther and S Lotfi and S S Rivas and D Bl\"{a}tte and J P Hofmann and T Bein and T Ameri},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adfm.202209768},

doi = {https://doi.org/10.1002/adfm.202209768},

issn = {1616-301X},

year  = {2023},

date = {2023-01-15},

journal = {Advanced Functional Materials},

volume = {33},

number = {13},

pages = {2209768},

abstract = {Abstract Although zinc oxide (ZnO) is one of the most commonly used materials for electron transport layers in organic solar cells (OSCs), it also comes with disadvantages such as the so-called light-soaking issues, i.e., its need for exposure to UV light to reach its full potential in OSCs. Here, the impact of ZnO light-soaking issues on stability measurements of OSCs is investigated. It is found that in the absence of UV light a reversible degradation occurs, which is independent of the used active layer material and accelerates at higher temperatures but can be undone with a short UV exposure. This reversible aging is attributed to the re-adsorption of oxygen, which for manufacturing reasons is trapped at the interface of ZnO, even in an oxygen-free environment. This oxygen can be removed with a UV pretreatment of the ZnO but at the expense of device efficiency and production that has to take place in an oxygen-free environment. This study establishes that stability measurements of ZnO-containing OSCs must be performed exclusively with a light source including a UV part since the usage of a simple white light source \textendash as often reported in the literature \textendash can lead to erroneous results.},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Highly selective monomethylation of amines with CO2/H2 via Ag/Al2O3 as catalyst},

author = {Y Long and J He and H Zhang and Y Chen and K Liu and J Fu and H Li and L Zhu and Z Lin and A Stefancu and E Cortes and M Zhu and M Liu},

url = {https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/chem.202203152},

doi = {https://doi.org/10.1002/chem.202203152},

issn = {0947-6539},

year  = {2023},

date = {2023-01-10},

journal = {Chemistry \textendash A European Journal},

volume = {n/a},

number = {n/a},

abstract = {The selective synthesis of monomethylated amines with CO2 is particularly challenging because the formation of tertiary amines is thermodynamically more favorable. Here we explore a new strategy for the controllable synthesis of N-monomethylated amines from primary amines and CO2/H2. Our first-principle calculations reveal that the dissociation of H2 via an heterolytic route reduces the reactivity of methylated amines and thus inhibit successive methylation. In-situ DRIFTS prove the process of formation and decomposition of ammonium salt by secondary amine reversible binding with H+ on the Ag/Al2O3 catalyst, thereby reducing its reactivity. Meanwhile, the energy barrier for rate-determining step of monomehylation was much lower than that of over methylation (0.34 eV vs 0.58 eV) means amines monomethylation in preference to successive methylation. Under optimal reaction conditions, a variety of amines conversion to corresponding monomethylated amines in good to excellent yields, and more than 90% yield of product obtained.},

keywords = {Molecularly-Functionalized, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Covalent Organic Framework Thin-Film Photodetectors from Solution-Processable Porous Nanospheres},

author = {S Bag and H S Sasmal and S P Chaudhary and K Dey and D Bl\"{a}tte and R Guntermann and Y Zhang and M Polo\v{z}ij and A Kuc and A Shelke and R K Vijayaraghavan and T G Ajithkumar and S Bhattacharyya and T Heine and T Bein and R Banerjee},

url = {https://doi.org/10.1021/jacs.2c09838},

doi = {10.1021/jacs.2c09838},

issn = {0002-7863},

year  = {2023},

date = {2023-01-09},

journal = {Journal of the American Chemical Society},

volume = {145},

number = {3},

pages = {1649-1659},

abstract = {The synthesis of homogeneous covalent organic framework (COF) thin films on a desired substrate with decent crystallinity, porosity, and uniform thickness has great potential for optoelectronic applications. We have used a solution-processable sphere transmutation process to synthesize 300 ± 20 nm uniform COF thin films on a 2 × 2 cm2 TiO2-coated fluorine-doped tin oxide (FTO) surface. This process controls the nucleation of COF crystallites and molecular morphology that helps the nanospheres to arrange periodically to form homogeneous COF thin films. We have synthesized four COF thin films (TpDPP, TpEtBt, TpTab, and TpTta) with different functional backbones. In a close agreement between the experiment and density functional theory, the TpEtBr COF film showed the lowest optical band gap (2.26 eV) and highest excited-state lifetime (8.52 ns) among all four COF films. Hence, the TpEtBr COF film can participate in efficient charge generation and separation. We constructed optoelectronic devices having a glass/FTO/TiO2/COF-film/Au architecture, which serves as a model system to study the optoelectronic charge transport properties of COF thin films under dark and illuminated conditions. Visible light with a calibrated intensity of 100 mW cm\textendash2 was used for the excitation of COF thin films. All of the COF thin films exhibit significant photocurrent after illumination with visible light in comparison to the dark. Hence, all of the COF films behave as good photoactive substrates with minimal pinhole defects. The fabricated out-of-plane photodetector device based on the TpEtBr COF thin film exhibits high photocurrent density (2.65 ± 0.24 mA cm\textendash2 at 0.5 V) and hole mobility (8.15 ± 0.64 ×10\textendash3 cm2 V\textendash1 S\textendash1) compared to other as-synthesized films, indicating the best photoactive characteristics.},

keywords = {Foundry Organic, Molecularly-Functionalized, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Gold Nanorod DNA Origami Antennas for 3 Orders of Magnitude Fluorescence Enhancement in NIR},

author = {K Trofymchuk and K Ko\l\k{a}taj and V Glembockyte and F Zhu and G P Acuna and T Liedl and P Tinnefeld},

url = {https://doi.org/10.1021/acsnano.2c09577},

doi = {10.1021/acsnano.2c09577},

issn = {1936-0851},

year  = {2023},

date = {2023-01-03},

journal = {ACS Nano},

volume = {17},

number = {2},

pages = {1327-1334},

abstract = {DNA origami has taken a leading position in organizing materials at the nanoscale for various applications such as manipulation of light by exploiting plasmonic nanoparticles. We here present the arrangement of gold nanorods in a plasmonic nanoantenna dimer enabling up to 1600-fold fluorescence enhancement of a conventional near-infrared (NIR) dye positioned at the plasmonic hotspot between the nanorods. Transmission electron microscopy, dark-field spectroscopy, and fluorescence analysis together with numerical simulations give us insights on the heterogeneity of the observed enhancement values. The size of our hotspot region is ∼12 nm, granted by using the recently introduced design of NAnoantenna with Cleared HotSpot (NACHOS), which provides enough space for placing of tailored bioassays. Additionally, the possibility to synthesize nanoantennas in solution might allow for production upscaling.},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Subsurface Engineering Induced Fermi Level De-pinning in Metal Oxide Semiconductors for Photoelectrochemical Water Splitting},

author = {J Wang and G Ni and W Liao and K Liu and J Chen and F Liu and Z Zhang and M Jia and J Li and J Fu and E Pensa and L Jiang and Z Bian and E Cortes and M Liu},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202217026},

doi = {https://doi.org/10.1002/anie.202217026},

issn = {1433-7851},

year  = {2022},

date = {2022-12-28},

journal = {Angewandte Chemie International Edition},

volume = {n/a},

number = {n/a},

abstract = {Photoelectrochemical (PEC) water splitting is a promising approach for renewable solar light conversion. However, surface Fermi level pinning (FLP), caused by surface trap states, severely restricts the PEC activities. Theoretical calculations indicate subsurface oxygen vacancy (sub-Ov) could release the FLP and retain the active structure. A series of metal oxide semiconductors with sub-Ov were prepared through precisely regulated spin-coating and calcination. Etching X-ray photoelectron spectroscopy (XPS), scanning transmission electron microscopy (STEM), and electron energy loss spectra (EELS) demonstrated Ov located at sub ~2-5 nm region. Mott-Schottky and open circuit photovoltage results confirmed the surface trap states elimination and Fermi level de-pinning. Thus, superior PEC performances of 5.1, 3.4, and 2.1 mA cm-2 at 1.23 V vs. RHE were achieved on BiVO4, Bi2O3, TiO2 with outstanding stability for 72 h, outperforming most reported works under the identical conditions.},

keywords = {Molecularly-Functionalized, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Waterborne conductive carbon paste with an eco-friendly binder},

author = {M Shadabfar and M Ehsani and H A Khonakdar and M Abdouss and T Ameri},

url = {https://doi.org/10.1007/s10570-022-04998-5},

doi = {10.1007/s10570-022-04998-5},

issn = {1572-882X},

year  = {2022},

date = {2022-12-22},

journal = {Cellulose},

abstract = {Conductive carbon pastes are widely used in flexible and printed electronic devices such as wearable electronics and optoelectronics. The use of conductive pastes comes with some challenges, such as replacing toxic synthetic materials with environmentally-friendly and sustainable ones, achieving an appropriate level of electrical conductivity, and controlling the thickness of the coated film. Waterborne conductive carbon pastes have been used to tackle the mentioned problems. In this study, carboxymethyl cellulose (CMC) was introduced as an eco-friendly binder combined with Graphene Nanoplatelets (GNPs) and Carbon Nanotubes (CNTs) to synthesize a conductive carbon paste without any metallic elements. The double-coated GNP/CNT/CMC paste films were coated on a paper surface using the doctor blade method. Morphological and thermal characteristics, sheet resistance, and optoelectrical properties of the paste films were comprehensively investigated. It was found that the conductive carbon paste containing 35 wt% CNTs exhibits higher conductivity (80.4 S/m) than the other combinations. Moreover, Field Emission Scanning Electron Microscopy (FE-SEM) showed that GNPs and CNTs are distributed within cellulosic matrix very homogeneously. Great flexibility and high electrical conductivity are achieved in the paste film. EIS results implied that the double-coated paste could act as a highly conductive surface in fabricating electrochemical sensors with high performance. In conclusion, this study represents a novel and environmentally-friendly method to produce low-cost, highly-efficient, and large-scale conductive carbon paste.},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Morphology Matters: 0D/2D WO3 Nanoparticle-Ruthenium Oxide Nanosheet Composites for Enhanced Photocatalytic Oxygen Evolution Reaction Rates},

author = {H A Vignolo-Gonz\'{a}lez and A Gouder and S Laha and V Duppel and S Carretero-Palacios and A Jim\'{e}nez-Solano and T Oshima and P Sch\"{u}tzend\"{u}be and B V Lotsch},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/aenm.202203315},

doi = {https://doi.org/10.1002/aenm.202203315},

issn = {1614-6832},

year  = {2022},

date = {2022-12-22},

journal = {Advanced Energy Materials},

volume = {n/a},

number = {n/a},

pages = {2203315},

abstract = {Abstract In the field of artificial photosynthesis with semiconductor light harvesters, the default cocatalyst morphologies are isotropic, 0D nanoparticles. Herein, the use of highly anisotropic 2D ruthenium oxide nanosheet (RONS) cocatalysts as an approach to enhance photocatalytic oxygen evolution (OER) rates on commercial WO3 nanoparticles (0D light harvester) is presented. At optimal cocatalyst loadings and identical photocatalysis conditions, WO3 impregnated with RONS (RONS/WO3) shows a fivefold increase in normalized photonic efficiency compared to when it is impregnated with conventional ruthenium oxide (rutile) nanoparticles (RONP/WO3). The superior RONS/WO3 performance is attributed to two special properties of the RONS: i) lower electrochemical water oxidation overpotential for RONS featuring highly active edge sites, and ii) decreased parasitic light absorption on RONS. Evidence is presented that OER photocatalytic performance can be doubled with control of RONS edges and it is shown that compared to WO3 impregnated with RONP, the advantageous optical properties and geometry of RONS decrease the fraction of light absorbed by the cocatalyst, thus reducing the parasitic light absorption on the RONS/WO3 composite. Therefore, the results presented in the current study are expected to promote engineering of cocatalyst morphology as a complementary concept to optimize light harvester-cocatalyst composites for enhanced photocatalytic efficiency.},

keywords = {Foundry Inorganic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Spatially-Modulated Silicon Interface Energetics Via Hydrogen Plasma-Assisted Atomic Layer Deposition of Ultrathin Alumina},

author = {A Henning and J D Bartl and L Wolz and M Christis and F Rauh and M Bissolo and T Gr\"{u}nleitner and J Eichhorn and P Zeller and M Amati and L Gregoratti and J J Finley and B Rieger and M Stutzmann and I D Sharp},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/admi.202202166},

doi = {https://doi.org/10.1002/admi.202202166},

issn = {2196-7350},

year  = {2022},

date = {2022-12-16},

journal = {Advanced Materials Interfaces},

volume = {n/a},

number = {n/a},

pages = {2202166},

abstract = {Abstract Atomic layer deposition (ALD) is a key technique for the continued scaling of semiconductor devices, which increasingly relies on scalable processes for interface manipulation of structured surfaces on the atomic level. While ALD allows the synthesis of conformal films with utmost control over the thickness, atomically-defined closed coatings and surface modifications are challenging to achieve because of 3D growth during nucleation. Here, a route is presented toward the sub-nanometer thin and continuous aluminum oxide (AlOx) coatings on silicon substrates for the spatial control of the surface charge density and interface energetics. Trimethylaluminum in combination with remote hydrogen plasma is used instead of a gas-phase oxidant for the transformation of silicon dioxide (SiO2) into alumina. Depending on the number of ALD cycles, the SiO2 can be partially or fully transformed, which is exploited to deposit ultrathin AlOx layers in selected regions defined by lithographic patterning. The resulting patterned surfaces are characterized by lateral AlOx/SiO2 interfaces possessing 0.3 nm step heights and surface potential steps exceeding 0.4 V. In addition, the introduction of fixed negative charges of 9 × 1012 cm−2 enables modulation of the surface band bending, which is relevant to the field-effect passivation of silicon and low-impedance charge transfer across contact interfaces.},

keywords = {Molecularly-Functionalized, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Boosting Nitrogen Activation via Ag Nanoneedle Arrays for Efficient Ammonia Synthesis},

author = {W Liao and K Liu and J Wang and A Stefancu and Q Chen and K Wu and Y Zhou and H Li and L Mei and M Li and J Fu and M Miyauchi and E Cort\'{e}s and M Liu},

url = {https://doi.org/10.1021/acsnano.2c08853},

doi = {10.1021/acsnano.2c08853},

issn = {1936-0851},

year  = {2022},

date = {2022-12-16},

journal = {ACS Nano},

abstract = {Electrocatalytic N2 reduction reaction (eNRR) provides a promising carbon-neutral and sustainable ammonia-synthesizing alternative to the Haber-Bosch process. However, the nonpolar N2 has significant thermodynamic stability and requires ultrahigh energy to break down the N≡N bond. Here, we report the construction of local enhanced electric fields (LEEFs) by Ag nanoneedle arrays to promote N≡N fracture thus assisting the eNRR. The LEEFs could induce charge polarization on nitrogen atoms and reduce the energy barrier in the N2 first-protonation step. The detected N─N and N─H intermediates prove the cleavage of the N≡N bond and the hydrogenation of N2 by LEEFs. The increased LEEFs lead to logarithmic growth rates for the targeted eNRR and exponential growth rates for the unavoidable competitive hydrogen evolution reaction. Thus, regulation and tuning of LEEFs to ∼4 × 104 kV m\textendash1 endows the raise of eNRR to the summit, achieving high ammonia selectivity with a Faradaic efficiency of 72.3 ± 4.0%.},

keywords = {Molecularly-Functionalized, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Charge transport in single polymer fiber transistors in the sub 100 nm regime: temperature dependence and Coulomb blockade},

author = {J Lenz and M Statz and K Watanabe and T Taniguchi and F Ortmann and R T Weitz},

url = {https://iopscience.iop.org/article/10.1088/2515-7639/aca82f/meta},

doi = {10.1088/2515-7639/aca82f},

issn = {2515-7639},

year  = {2022},

date = {2022-12-15},

journal = {Journal of Physics: Materials},

abstract = {Even though charge transport in semiconducting polymers is of relevance for a number of potential applications in (opto-)electronic devices, the fundamental mechanism of how charges are transported through organic polymers that are typically characterized by a complex nanostructure is still open. One of the challenges which we address here, is how to gain controllable experimental access to charge transport at the sub-100 nm lengthscale. To this end charge transport in single poly(diketopyrrolopyrrole-terthiophene) fiber transistors, employing two different solid gate dielectrics, a hybrid Al2O3/self-assembled monolayer and hexagonal boron nitride, is investigated in the sub-50 nm regime using electron-beam contact patterning. The electrical characteristics exhibit near ideal behavior at room temperature which demonstrates the general feasibility of the nanoscale contacting approach, even though the channels are only a few nanometers in width. At low temperatures, we observe nonlinear behavior in the current\textendashvoltage characteristics in the form of Coulomb diamonds which can be explained by the formation of an array of multiple quantum dots at cryogenic temperatures.},

keywords = {Molecularly-Functionalized, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Using Metal\textendashOrganic Frameworks to Confine Liquid Samples for Nanoscale NV-NMR},

author = {K S Liu and X Ma and R Rizzato and A L Semrau and A Henning and I D Sharp and R A Fischer and D B Bucher},

url = {https://doi.org/10.1021/acs.nanolett.2c03069},

doi = {10.1021/acs.nanolett.2c03069},

issn = {1530-6984},

year  = {2022},

date = {2022-12-08},

journal = {Nano Letters},

abstract = {Atomic-scale magnetic field sensors based on nitrogen vacancy (NV) defects in diamonds are an exciting platform for nanoscale nuclear magnetic resonance (NMR) spectroscopy. The detection of NMR signals from a few zeptoliters to single molecules or even single nuclear spins has been demonstrated using NV centers close to the diamond surface. However, fast molecular diffusion of sample molecules in and out of the nanoscale detection volumes impedes their detection and limits current experiments to solid-state or highly viscous samples. Here, we show that restricting diffusion by confinement enables nanoscale NMR spectroscopy of liquid samples. Our approach uses metal\textendashorganic frameworks (MOF) with angstrom-sized pores on a diamond chip to trap sample molecules near the NV centers. This enables the detection of NMR signals from a liquid sample, which would not be detectable without confinement. These results set the route for nanoscale liquid-phase NMR with high spectral resolution.},

keywords = {Molecularly-Functionalized, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Antisolvent Additive Engineering for Boosting Performance and Stability of Graded Heterojunction Perovskite Solar Cells Using Amide-Functionalized Graphene Quantum Dots},

author = {E Khorshidi and B Rezaei and A Kavousighahfarokhi and J Hanisch and M A Reus and P M\"{u}ller-Buschbaum and T Ameri},

url = {https://doi.org/10.1021/acsami.2c12944},

doi = {10.1021/acsami.2c12944},

issn = {1944-8244},

year  = {2022},

date = {2022-11-29},

journal = {ACS Applied Materials \& Interfaces},

volume = {14},

number = {49},

pages = {54623-54634},

abstract = {Additive and antisolvent engineering strategies are outstandingly efficient in enhancing perovskite quality, photovoltaic performance, and stability of perovskite solar cells (PSCs). In this work, an effective approach is applied by coupling the antisolvent mixture and multi-functional additive procedures, which is recognized as antisolvent additive engineering (AAE). The graphene quantum dots functionalized with amide (AGQDs), which consists of carbonyl, amine, and long hydrophobic alkyl chain functional groups, are added to the antisolvent mixture of toluene (T) and hexane (H) as an efficient additive to form the CH3NH3PbI3 (MAPI):AGQDs graded heterojunction structure. A broad range of analytical techniques, including scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, space charge limited current, UV\textendashvisible spectroscopy, external quantum efficiency, and time-of-flight secondary ion mass spectrometry, are used to investigate the effect of AAE treatment with AGQDs on the quality of perovskite film and performance of the PSCs. Importantly, not only a uniform and dense perovskite film with hydrophobic property is obtained but also defects on the perovskite surface are significantly passivated by the interaction between AGQDs and uncoordinated Pb2+. As a result, an enhanced power conversion efficiency (PCE) of 19.10% is achieved for the champion PSCs treated with AGQD additive, compared to the PCE of 16.00% for untreated reference PSCs. In addition, the high-efficiency PSCs based on AGQDs show high stability and maintain 89% of their initial PCE after 960 h in ambient conditions.},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Direct Coupling of Methane and Carbon Dioxide on Tantalum Cluster Cations},

author = {J Lengyel and N Levin and M On\v{c}\'{a}k and K Jakob and M Tschurl and U Heiz},

url = {https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/chem.202203259},

doi = {https://doi.org/10.1002/chem.202203259},

issn = {0947-6539},

year  = {2022},

date = {2022-11-20},

journal = {Chemistry \textendash A European Journal},

volume = {n/a},

number = {n/a},

abstract = {Understanding molecular-scale reaction mechanisms is crucial for the design of modern catalysts with industrial prospect. Through joint experimental and computational studies, we investigate the direct coupling reaction of CH4 and CO2, two abundant greenhouse gases, mediated by Ta1,4+ ions to form larger oxygenated hydrocarbons. Coherent with proposed elementary steps, we expose products of CH4 dehydrogenation [Ta1,4CH2]+ to CO2 in a ring electrode ion trap. Product analysis and reaction kinetics indicate a predisposition of the tetramers for C\textendashO coupling with a conversion to products of CH2O, whereas atomic cations enable C\textendashC coupling yielding CH2CO. Many of the experimental findings are supported by thermodynamic computations, connecting structure, electronic properties, and catalyst function. Moreover, the study of bare Ta1,4+ compounds indicates that methane dehydrogenation is a significant initial step in the direct coupling reaction, enabling new, yet unknown reaction pathways.},

keywords = {Foundry Inorganic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Advances in ultrafast plasmonics},

author = {A N Koya and M Romanelli and J Kuttruff and N Henriksson and A Stefancu and G Grinblat and A De Andres and F Schnur and M Vanzan and M Marsili},

url = {https://arxiv.org/abs/2211.08241},

doi = {https://doi.org/10.48550/arXiv.2211.08241},

year  = {2022},

date = {2022-11-15},

journal = {arXiv preprint arXiv:2211.08241},

abstract = {In the past twenty years, we have reached a broad understanding of many light-driven phenomena in nanoscale systems. The temporal dynamics of the excited states are instead quite challenging to explore, and, at the same time, crucial to study for understanding the origin of fundamental physical and chemical processes. In this review we examine the current state and prospects of ultrafast phenomena driven by plasmons both from a fundamental and applied point of view. This research area is referred to as ultrafast plasmonics and represents an outstanding playground to tailor and control fast optical and electronic processes at the nanoscale, such as ultrafast optical switching, single photon emission and strong coupling interactions to tailor photochemical reactions. Here, we provide an overview of the field, and describe the methodologies to monitor and control nanoscale phenomena with plasmons at ultrafast timescales in terms of both modeling and experimental characterization. Various directions are showcased, among others recent advances in ultrafast plasmon-driven chemistry and multi-functional plasmonics, in which charge, spin, and lattice degrees of freedom are exploited to provide active control of the optical and electronic properties of nanoscale materials. As the focus shifts to the development of practical devices, such as all-optical transistors, we also emphasize new materials and applications in ultrafast plasmonics and highlight recent development in the relativistic realm. The latter is a promising research field with potential applications in fusion research or particle and light sources providing properties such as attosecond duration.},

keywords = {Molecularly-Functionalized, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Microfluidic quantum sensing platform for lab-on-a-chip applications},

author = {R D Allert and F Bruckmaier and N R Neuling and F A Freire-Moschovitis and K S Liu and C Schrepel and P Sch\"{a}tzle and P Knittel and M Hermans and D B Bucher},

url = {http://dx.doi.org/10.1039/D2LC00874B},

doi = {10.1039/D2LC00874B},

issn = {1473-0197},

year  = {2022},

date = {2022-11-10},

journal = {Lab on a Chip},

volume = {22},

number = {24},

pages = {4831-4840},

abstract = {Lab-on-a-chip (LOC) applications have emerged as invaluable physical and life sciences tools. The advantages stem from advanced system miniaturization, thus, requiring far less sample volume while allowing for complex functionality, increased reproducibility, and high throughput. However, LOC applications necessitate extensive sensor miniaturization to leverage these inherent advantages fully. Atom-sized quantum sensors are highly promising to bridge this gap and have enabled measurements of temperature, electric and magnetic fields on the nano- to microscale. Nevertheless, the technical complexity of both disciplines has so far impeded an uncompromising combination of LOC systems and quantum sensors. Here, we present a fully integrated microfluidic platform for solid-state spin quantum sensors, like the nitrogen-vacancy (NV) center in diamond. Our platform fulfills all technical requirements, such as fast spin manipulation, enabling full quantum sensing capabilities, biocompatibility, and easy adaptability to arbitrary channel and chip geometries. To illustrate the vast potential of quantum sensors in LOC systems, we demonstrate various NV center-based sensing modalities for chemical analysis in our microfluidic platform, ranging from paramagnetic ion detection to high-resolution microscale NV-NMR. Consequently, our work opens the door for novel chemical analysis capabilities within LOC devices with applications in electrochemistry, high-throughput reaction screening, bioanalytics, organ-on-a-chip, or single-cell studies.},

keywords = {Molecularly-Functionalized, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Mirror-coupled plasmonic bound states in the continuum for tunable perfect absorption},

author = {J Wang and T Weber and A Aigner and S A Maier and A Tittl},

url = {https://arxiv.org/abs/2211.03673},

doi = {https://doi.org/10.48550/arXiv.2211.03673},

year  = {2022},

date = {2022-11-07},

journal = {arXiv preprint arXiv:2211.03673},

abstract = {Tailoring critical light-matter coupling is a fundamental challenge of nanophotonics, impacting diverse fields from higher harmonic generation and energy conversion to surface-enhanced spectroscopy. Plasmonic perfect absorbers (PAs), where resonant antennas couple to their mirror images in adjacent metal films, have been instrumental for obtaining different coupling regimes by tuning the antenna-film distance. However, for on-chip uses, the ideal PA gap size can only match one wavelength, and wide range multispectral approaches remain challenging. Here, we introduce a new paradigm for plasmonic PAs by combining mirror-coupled resonances with the unique loss engineering capabilities of plasmonic bound states in the continuum (BICs). Our BIC-driven PA platform leverages the asymmetry of the constituent meta-atoms as an additional degree of freedom for reaching the critical coupling (CC) condition, delivering resonances with unity absorbance and high quality factors approaching 100 in the mid-infrared. Such a platform holds flexible tuning knobs including asymmetry parameter, dielectric gap, and geometrical scaling factor to precisely control the coupling condition, resonance frequency, and selective enhancement of magnetic and electric fields while maintaining CC. We demonstrate a pixelated PA metasurface with optimal absorption over a broad range of mid-infrared frequencies (950 ~ 2000 1/cm) using only a single spacer layer thickness and apply it for multispectral surface-enhanced molecular spectroscopy in tailored coupling regimes. Our concept greatly expands the capabilities and flexibility of traditional gap-tuned PAs, opening new perspectives for miniaturized sensing platforms towards on-chip and in-situ detection.},

keywords = {Molecularly-Functionalized, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Picosecond Charge-Transfer-State Dynamics in Wide Band Gap Polymer\textendashNon-Fullerene Small-Molecule Blend Films Investigated via Transient Infrared Spectroscopy},

author = {M Nuber and L V Spanier and S Roth and G N Vayssilov and R Kienberger and P M\"{u}ller-Buschbaum and H Iglev},

url = {https://doi.org/10.1021/acs.jpclett.2c02864},

doi = {10.1021/acs.jpclett.2c02864},

year  = {2022},

date = {2022-11-03},

journal = {The Journal of Physical Chemistry Letters},

pages = {10418-10423},

abstract = {Organic solar cells based on wide band gap polymers and nonfullerene small-molecule acceptors have demonstrated remarkably good device performances. Nevertheless, a thorough understanding of the charge-transfer process in these materials has not been achieved yet. In this study, we use Fano resonance signals caused by the interaction of broad electronic charge carrier absorption and the molecular vibrations of the electron acceptor molecule to monitor the charge-transfer state dynamics. In our time-resolved infrared spectroscopy experiments, we find that in the small-molecule acceptor, they have additional dynamics on the order of a few picoseconds. A change in the solvent used in thin film deposition, leading to different morphologies, influences this time further. We interpret our findings as the dynamics of the charge-transfer state at the interface of the electron donor and the electron- acceptor. The additional mid-infrared transient signal is generated in this state, as both electron and hole polarons can interact with small-molecule acceptor vibrational modes.},

keywords = {Molecularly-Functionalized, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Permittivity-asymmetric quasi-bound states in the continuum},

author = {R Bert\'{e} and T Weber and L D S Menezes and L K\"{u}hner and A Aigner and M Barkey and F J Wendisch and Y S Kivshar and A Tittl and S A Maier},

url = {https://arxiv.org/abs/2211.01176},

doi = {https://doi.org/10.48550/arXiv.2211.01176},

year  = {2022},

date = {2022-11-02},

journal = {arXiv preprint arXiv:2211.01176},

abstract = {Broken symmetries lie at the heart of nontrivial physical phenomena. Breaking the in-plane geometrical symmetry of optical systems allows to access a set of electromagnetic states termed symmetry-protected quasi-bound states in the continuum (qBICs). Here we demonstrate, theoretically, numerically and experimentally, that such optical states can also be accessed in metasurfaces by breaking the in-plane symmetry in the permittivity of the comprising materials, showing a remarkable equivalence to their geometrically-asymmetric counterparts. However, while the physical size of atoms imposes a limit on the lowest achievable geometrical asymmetry, weak permittivity modulations due to carrier doping and electro-optical Pockels and Kerr effects, usually considered insignificant, open up the possibility of infinitesimal permittivity asymmetries for on-demand, and dynamically tuneable optical resonances of extremely high quality factors. We probe the excitation of permittivity-asymmetric qBICs (ε-qBICs) using a prototype Si/TiO2 metasurface, in which the asymmetry in the unit cell is provided by the refractive index contrast of the dissimilar materials, surpassing any unwanted asymmetries from nanofabrication defects or angular deviations of light from normal incidence. ε-qBICs can also be excited in 1D gratings, where quality-factor enhancement and tailored interference phenomena via the interplay of geometrical and permittivity asymmetries are numerically demonstrated. The emergence of ε-qBICs in systems with broken symmetries in their permittivity may enable to test time-energy uncertainties in quantum mechanics, and lead to a whole new class of low-footprint optical and optoelectronic devices, from arbitrarily narrow filters and topological sources, biosensing and ultrastrong light-matter interaction platforms, to tuneable optical switches.},

keywords = {Molecularly-Functionalized, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Ultra-Sensitive Extinction Measurements of Optically Active Defects in Monolayer MoS2},

author = {F Sigger and I Amersdorffer and A H\"{o}tger and M Nutz and J Kiemle and T Taniguchi and K Watanabe and M F\"{o}rg and J Noe and J J Finley and A H\"{o}gele and A W Holleitner and T H\"{u}mmer and D Hunger and C Kastl},

url = {https://doi.org/10.1021/acs.jpclett.2c02386},

doi = {10.1021/acs.jpclett.2c02386},

year  = {2022},

date = {2022-10-28},

journal = {The Journal of Physical Chemistry Letters},

pages = {10291-10296},

abstract = {We utilize cavity-enhanced extinction spectroscopy to directly quantify the optical absorption of defects in MoS2 generated by helium ion bombardment. We achieve hyperspectral imaging of specific defect patterns with a detection limit below 0.01% extinction, corresponding to a detectable defect density below 1 × 1011 cm\textendash2. The corresponding spectra reveal a broad subgap absorption, being consistent with theoretical predictions related to sulfur vacancy-bound excitons in MoS2. Our results highlight cavity-enhanced extinction spectroscopy as efficient means for the detection of optical transitions in nanoscale thin films with weak absorption, applicable to a broad range of materials.},

keywords = {Molecularly-Functionalized, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Q-Band relaxation in chlorophyll: new insights from multireference quantum dynamics},

author = {S Reiter and L B\"{a}uml and J Hauer and R De Vivie-Riedle},

url = {http://dx.doi.org/10.1039/D2CP02914F},

doi = {10.1039/D2CP02914F},

issn = {1463-9076},

year  = {2022},

date = {2022-10-27},

journal = {Physical Chemistry Chemical Physics},

abstract = {The ultrafast relaxation within the Q-bands of chlorophyll plays a crucial role in photosynthetic light-harvesting. Yet, despite being the focus of many experimental and theoretical studies, it is still not fully understood. In this paper we look at the relaxation process from the perspective of non-adiabatic wave packet dynamics. For this purpose, we identify vibrational degrees of freedom which contribute most to the non-adiabatic coupling. Using a selection of normal modes, we construct four reduced-dimensional coordinate spaces and investigate the wave packet dynamics on XMS-CASPT2 potential energy surfaces. In this context, we discuss the associated computational challenges, as many quantum chemical methods overestimate the Qx\textendashQy energy gap. Our results show that the Qx and Qy potential energy surfaces do not cross in an energetically accessible region of the vibrational space. Instead, non-adiabatic coupling facilitates ultrafast population transfer across the potential energy surface. Moreover, we can identify the excited vibrational eigenstates that take part in the relaxation process. We conclude that the Q-band system of chlorophyll a should be viewed as a strongly coupled system, where population is easily transferred between the x and y-polarized electronic states. This suggests that both orientations may contribute to the electron transfer in the reaction center of photosynthetic light-harvesting systems.},

keywords = {Molecularly-Functionalized, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Hot Carrier Dynamics in InAs-AlAsSb Core-Shell Nanowires},

author = {D Sandner and H Esmaielpour and F Del Giudice and M Nuber and R Kienberger and G Koblm\"{u}ller and H Iglev},

url = {https://arxiv.org/abs/2210.11886},

doi = {https://doi.org/10.48550/arXiv.2210.11886},

year  = {2022},

date = {2022-10-25},

journal = {arXiv preprint arXiv:2210.11886},

abstract = {Semiconductor nanowires (NWs) have shown evidence of robust hot carrier effects due to their small dimensions. The relaxation dynamics of hot carriers in these nanostructures, generated by photo-absorption, are of great importance in optoelectronic devices and high efficiency solar cells, such as hot carrier solar cells. Among various III-V semiconductors, indium arsenide (InAs) NWs are promising candidates for their applications in advanced light harvesting devices due to their high photo-absorptivity and high mobility. Here, we investigate the hot carrier dynamics in InAs-AlAsSb core-shell NWs, as well as bare-core InAs NWs, using ultrafast pump-probe spectroscopy with widely tuned pump and probe energies. We have found a lifetime of 2.3 ps for longitudinal optical (LO) phonons and hot electron lifetimes of about 3 ps and 30 ps for carrier-carrier interactions and electron-phonon interactions, respectively. In addition, we have investigated the electronic states in the AlAsSb-shell and found that, despite the large band offset of the core-shell design in the conduction band, excited carriers remain in the shell longer than 100 ps. Our results indicate evidence of plasmon-tailored core-shell NWs for efficient light harvesting devices, which could open potential avenues for improving the efficiency of photovoltaic solar cells.},

keywords = {Foundry Inorganic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Crystal side facet-tuning of GaN nanowires and nanofins grown by molecular beam epitaxy},

author = {F Pantle and M Karlinger and S W\"{o}rle and F Becker and T H\"{o}ldrich and E Sirotti and M Kraut and M Stutzmann},

url = {https://aip.scitation.org/doi/abs/10.1063/5.0098016},

doi = {10.1063/5.0098016},

year  = {2022},

date = {2022-10-22},

journal = {Journal of Applied Physics},

volume = {132},

number = {18},

pages = {184304},

abstract = {GaN nanostructures are promising for a broad range of applications due to their 3D structure, thereby exposing non-polar crystal surfaces. The nature of the exposed crystal facets, i.e., whether they are a-, m-plane, or of mixed orientation, impacts the stability and performance of GaN nanostructure-based devices. In this context, it is of great interest to control the formation of well-defined side facets. Here, we show that we can control the crystal facet formation at the nanowire sidewalls by tuning the III\textendashV ratio during selective area growth by molecular beam epitaxy. Especially, the N flux serves as a tool for controlling the growth kinetics. In addition, we demonstrate the growth of GaN nanofins with either a- or m-plane side facets. Based on our observations, we present the underlying nanostructure growth mechanisms. Low temperature photoluminescence measurements show a correlation of the formation of structural defects like stacking faults with the growth kinetics. This article demonstrates the controlled selective epitaxy of GaN nanostructures with defined crystal side facets on large-scale available AlN substrates.},

keywords = {Foundry Inorganic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Emerging noble metal-free Mo-based bifunctional catalysts for electrochemical energy conversion},

author = {S Santra and V Streibel and I D Sharp},

url = {https://doi.org/10.1007/s12274-022-5022-y},

doi = {10.1007/s12274-022-5022-y},

issn = {1998-0000},

year  = {2022},

date = {2022-10-22},

journal = {Nano Research},

volume = {15},

number = {12},

pages = {10234-10267},

abstract = {The transition from a global economy dependent on fossil fuels to one based on sustainable energy conversion technologies presents the primary challenge of the day. Equipping water electrolyzers and metal-air batteries with earth-abundant bifunctional transition metal (TM) catalysts that efficiently catalyse the hydrogen and oxygen evolution reactions (HER and OER) and the oxygen reduction and evolution reactions (ORR and OER), respectively, reduces the cost and system complexity, while also providing prospects for accelerated scaling and sustainable material reuse. Among the TMs, earth-abundant molybdenum (Mo)-based multifunctional catalysts are especially promising and have attracted considerable attention in recent years. Starting with a brief introduction to HER, OER, and ORR mechanisms and parameters governing their bifunctionality, this comprehensive review focuses on such Mo-based multifunctional catalysts. We review and discuss recent progress achieved through the formation of Mo-based compounds, heterostructures, and nanoscale composites, as well as by doping, defect engineering, and nanoscale sculpting of Mo-based catalysts. The systems discussed in detail are based on Mo chalcogenides, carbides, oxides, nitrides, and phosphides, as well as Mo alloys, highlighting specific opportunities afforded by synergistic interactions of Mo with both non-metals and non-noble metals. Finally, we discuss the future of Mo-based multifunctional electrocatalysts for HER/OER, ORR/OER, and HER/ORR/OER, analysing emerging trends, new opportunities, and underexplored avenues in this promising materials space.},

keywords = {Molecularly-Functionalized, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Probing the ultrafast dynamics of excitons in single semiconducting carbon nanotubes},

author = {K Birkmeier and T Hertel and A Hartschuh},

url = {https://doi.org/10.1038/s41467-022-33941-2},

doi = {10.1038/s41467-022-33941-2},

issn = {2041-1723},

year  = {2022},

date = {2022-10-21},

journal = {Nature Communications},

volume = {13},

number = {1},

pages = {6290},

abstract = {Excitonic states govern the optical spectra of low-dimensional semiconductor nanomaterials and their dynamics are key for a wide range of applications, such as in solar energy harvesting and lighting. Semiconducting single-walled carbon nanotubes emerged as particularly rich model systems for one-dimensional nanomaterials and as such have been investigated intensively in the past. The exciton decay dynamics in nanotubes has been studied mainly by transient absorption and time-resolved photoluminescence spectroscopy. Since different transitions are monitored with these two techniques, developing a comprehensive model to reconcile different data sets, however, turned out to be a challenge and remarkably, a uniform description seems to remain elusive. In this work, we investigate the exciton decay dynamics in single carbon nanotubes using transient interferometric scattering and time-resolved photoluminescence microscopy with few-exciton detection sensitivity and formulate a unified microscopic model by combining unimolecular exciton decay and ultrafast exciton-exciton annihilation on a time-scale down to 200 fs.},

keywords = {Molecularly-Functionalized, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {High-Q nanophotonics over the full visible spectrum enabled by hexagonal boron nitride metasurfaces},

author = {L K\"{u}hner and L Sortino and B Tilmann and T Weber and K Watanabe and T Taniguchi and S A Maier and A Tittl},

url = {https://arxiv.org/abs/2210.11314},

doi = {https://doi.org/10.48550/arXiv.2210.11314},

year  = {2022},

date = {2022-10-20},

journal = {arXiv preprint arXiv:2210.11314},

abstract = {All-dielectric optical metasurfaces with high quality (Q) factors have so far been hampered by the lack of simultaneously lossless and high refractive index (RI) materials over the full visible spectrum. To achieve broad spectral coverage, the use of low-index materials is, in fact, unavoidable due to the inverse correlation between the band-gap energy (and therefore the optical losses) and the RI. However, for Mie resonant photonics, smaller RIs are associated with reduced Q factors and mode volume confinement. In this work, we leverage symmetry-broken bound states in the continuum (BICs) to efficiently suppress radiation losses from the low-index (n~2) van der Waals material hexagonal boron nitride (hBN), realizing metasurfaces with high-Q resonances over the complete visible spectrum. In particular, we analyze the rational use of low and high RI materials as resonator components and harness our insights to experimentally demonstrate sharp BIC resonances with Q factors above 300, spanning wavelengths between 400 nm and 1000 nm from a single hBN flake. Moreover, we utilize the enhanced electric near-fields to demonstrate second harmonic generation (SHG) with enhancement factors above 102. Our results provide a theoretical and experimental framework for the implementation of low RI materials as photonic media for metaoptics.},

keywords = {Molecularly-Functionalized, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Attenuating metal-substrate conjugation in atomically dispersed nickel catalysts for electroreduction of CO2 to CO},

author = {Q Wang and K Liu and K Hu and C Cai and H Li and H Li and M Herran and Y-R Lu and T-S Chan and C Ma and J Fu and S Zhang and Y Liang and E Cort\'{e}s and M Liu},

url = {https://doi.org/10.1038/s41467-022-33692-0},

doi = {10.1038/s41467-022-33692-0},

issn = {2041-1723},

year  = {2022},

date = {2022-10-14},

journal = {Nature Communications},

volume = {13},

number = {1},

pages = {6082},

abstract = {Atomically dispersed transition metals on carbon-based aromatic substrates are an emerging class of electrocatalysts for the electroreduction of CO2. However, electron delocalization of the metal site with the carbon support via d-π conjugation strongly hinders CO2 activation at the active metal centers. Herein, we introduce a strategy to attenuate the d-π conjugation at single Ni atomic sites by functionalizing the support with cyano moieties. In situ attenuated total reflection infrared spectroscopy and theoretical calculations demonstrate that this strategy increases the electron density around the metal centers and facilitates CO2 activation. As a result, for the electroreduction of CO2 to CO in aqueous KHCO3 electrolyte, the cyano-modified catalyst exhibits a turnover frequency of ~22,000 per hour at −1.178 V versus the reversible hydrogen electrode (RHE) and maintains a Faradaic efficiency (FE) above 90% even with a CO2 concentration of only 30% in an H-type cell. In a flow cell under pure CO2 at −0.93 V versus RHE the cyano-modified catalyst enables a current density of −300 mA/cm2 with a FE above 90%.},

keywords = {Molecularly-Functionalized, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Phase-Selective Four-Wave Mixing of Resonant Plasmonic Nanoantennas},

author = {V Giegold and K Ko\la̧Taj and T Liedl and A Hartschuh},

url = {https://doi.org/10.1021/acsphotonics.2c01362},

doi = {10.1021/acsphotonics.2c01362},

year  = {2022},

date = {2022-10-11},

journal = {ACS Photonics},

abstract = {Metallic nanoantennas are key components of a wide range of optical techniques that exploit their plasmonic response for signal amplification and extremely sensitive detection. For nonlinear techniques, the higher-order plasmonic response of a nanoantenna can be predicted by the product of the nanoantenna’s linear susceptibilities, known as Miller’s rule, provided that the spatial field distributions at the fundamental and the nonlinear frequencies are the same. Here, we show that Miller’s rule also holds for ultra-broadband excitation pulses and that it can be utilized to predict the frequency dependence of the near-degenerate four-wave mixing (ND-FWM) intensities generated by individual resonant plasmonic nanoantennas. Importantly, this implies that the nanoantenna’s nonlinear response can be deterministically controlled and further optimized by varying the spectral phase of the laser pulse. We demonstrate this by measuring the chirp dependence of the ND-FWM signal and observe an enhancement of up to 60% depending on the position of the plasmon resonance with respect to the laser spectrum, in agreement with model predictions. Finally, we exploit this phase control for chirp-selective confocal imaging of resonant nanoantennas. Our findings may help improve the sensitivity of nonlinear techniques such as plasmon-enhanced coherent anti-Stokes Raman scattering.},

keywords = {Molecularly-Functionalized, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Unlocking the out-of-plane dimension for photonic bound states in the continuum to achieve maximum optical chirality},

author = {L K\"{u}hner and F J Wendisch and A A Antonov and J B\"{u}rger and L H\"{u}ttenhofer and L D S Menezes and S A Maier and M V Gorkunov and Y Kivshar and A Tittl},

url = {https://arxiv.org/abs/2210.05339},

doi = {https://doi.org/10.48550/arXiv.2210.05339},

year  = {2022},

date = {2022-10-11},

journal = {arXiv preprint arXiv:2210.05339},

abstract = {The realization of lossless metasurfaces with true chirality crucially requires the fabrication of three-dimensional structures, constraining their feasibility for experiments and hampering practical implementations. Even though the three-dimensional assembly of metallic nanostructures has been demonstrated previously, the resulting plasmonic resonances suffer from high intrinsic and radiative losses. The concept of photonic bound states in the continuum (BICs) is instrumental for tailoring radiative losses in diverse geometries, especially when implemented using lossless dielectrics, but applications have so far been limited to planar and intrinsically achiral structures. Here, we introduce a novel nanofabrication approach to unlock the height of generally flat all-dielectric metasurfaces as an accessible parameter for efficient resonance and functionality control. In particular, we realize out-of-plane symmetry breaking in quasi-BIC metasurfaces and leverage this design degree of freedom to demonstrate, for the first time, an optical all-dielectric quasi-BIC metasurface with maximum intrinsic chirality that responds selectively to light of a particular circular polarization depending on the structural handedness. Our experimental results not only open a new paradigm for all-dielectric BICs and chiral nanophotonics but also promise advances in the realization of efficient generation of optical angular momentum, holographic metasurfaces, and parity-time symmetry-broken optical systems.},

keywords = {Molecularly-Functionalized, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Emitter-Optomechanical Interaction in high-Q hBN Nanocavities},

author = {C Qian and V Villafa\~{n}e and M Schalk and G V Astakhov and U Kentsch and M Helm and A H\"{o}tger and P Soubelet and A W Holleitner and A V Stier},

url = {https://arxiv.org/abs/2210.00150},

doi = {https://doi.org/10.48550/arXiv.2210.00150},

year  = {2022},

date = {2022-10-01},

journal = {arXiv preprint arXiv:2210.00150},

abstract = {We investigate the interaction between optically excited charged boron vacancies V−B, localized photonic modes of ultra-high-Q (∼105) nanocavities and local vibronic modes. V−B is a color center for which phonon-induced processes generally dominate the emission. A pronounced asymmetry is observed in the emission spectrum for cavities in which V−B centers have been generated by N+ irradiation. Similar asymmetries are not observed for systems that do not contain V−B centers. To explain our findings, we model the system as phonon-induced light-matter coupling with multi-partite interplay between the electronic transition, cavity photons and local vibronic modes. Good agreement is obtained between experiment and theory. Our results indicate that the multi-partite interplay arises during the V−B emission process, illustrating that it is phonon-induced, rather than being caused by thermal population of vibronic modes. The multi-modal couplings between various photonic (V−B emission, cavity nanophotonic) and vibronic (V−B phonons, cavity nanomechanical) modes provide novel method to interface spin, photons and phonons in condensed matter systems.},

keywords = {Foundry Inorganic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Metasurface Measuring Twisted Light in Turbulence},

author = {T Dinter and C Li and L K\"{u}hner and T Weber and A Tittl and S A Maier and J M Dawes and H Ren},

url = {https://doi.org/10.1021/acsphotonics.2c00800},

doi = {10.1021/acsphotonics.2c00800},

year  = {2022},

date = {2022-09-09},

journal = {ACS Photonics},

volume = {9},

number = {9},

pages = {3043-3051},

abstract = {Orbital angular momentum (OAM) of light represents an independent degree of freedom using orthogonal helical modes for optical and quantum multiplexing, offering great potential to transform future ultrahigh-bandwidth information systems. Practical OAM communication systems suffer from turbulence-induced phase distortions to the propagating beams, decreasing the orthogonality of OAM modes through introduced modal crosstalk. To date, optical systems used for measuring OAM orthogonality breakdown in different turbulence conditions are too bulky and slow (e.g., one OAM mode at a time) for any practical use. Here, we demonstrate the use of an ultrathin OAM mode-sorting metasurface for characterizing the OAM orthogonality breakdown under different turbulence conditions. Our approach allows the measurement of the whole OAM spectrum at the same time. This metasurface exhibits strong OAM selectivity with an average modal crosstalk below −42.4 dB for OAM modes with topological charges ranging from −15 to +15. Our results suggest that higher-order OAM modes are as robust as lower-order modes in particular turbulence environments, paving the way for future practical free-space OAM communications harnessing high-dimensional OAM multiplexing. We demonstrated that a flat optical device with a small form factor can be integrated with practical communication systems for compact, fast, and efficient generation and detection of twisted light.},

keywords = {Molecularly-Functionalized, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Heteroatoms Induce Localization of the Electric Field and Promote a Wide Potential-Window Selectivity Towards CO in the CO2 Electroreduction},

author = {C Cai and B Liu and K Liu and P Li and J Fu and Y Wang and W Li and C Tian and Y Kang and A Stefancu and H Li and C-W Kao and T-S Chan and Z Lin and L Chai and E Cort\'{e}s and M Liu},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202212640},

doi = {https://doi.org/10.1002/anie.202212640},

issn = {1433-7851},

year  = {2022},

date = {2022-09-08},

journal = {Angewandte Chemie International Edition},

volume = {61},

number = {44},

pages = {e202212640},

abstract = {Abstract Carbon dioxide electroreduction (CO2RR) is a sustainable way of producing carbon-neutral fuels. Product selectivity in CO2RR is regulated by the adsorption energy of reaction-intermediates. Here, we employ differential phase contrast-scanning transmission electron microscopy (DPC-STEM) to demonstrate that Sn heteroatoms on a Ag catalyst generate very strong and atomically localized electric fields. In situ attenuated total reflection infrared spectroscopy (ATR-IR) results verified that the localized electric field enhances the adsorption of *COOH, thus favoring the production of CO during CO2RR. The Ag/Sn catalyst exhibits an approximately 100 % CO selectivity at a very wide range of potentials (from −0.5 to −1.1 V, versus reversible hydrogen electrode), and with a remarkably high energy efficiency (EE) of 76.1 %.},

keywords = {Molecularly-Functionalized, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Synthesis of Ultra-Incompressible Carbon Nitrides Featuring Three-Dimensional Frameworks of CN4 Tetrahedra Recoverable at Ambient Conditions},

author = {D Laniel and F Trybel and A Aslandukov and S Khandarkhaeva and T Fedotenko and Y Yin and F Tasn\'{a}di and A V Ponomareva and G Weck and F I Akbar},

url = {https://arxiv.org/abs/2209.01968},

doi = {https://doi.org/10.48550/arXiv.2209.01968},

year  = {2022},

date = {2022-09-05},

journal = {arXiv preprint arXiv:2209.01968},

abstract = {More than thirty years ago, carbon nitrides featuring 3D frameworks of tetrahedral CN4 units were identified as one of the great aspirations of materials science, expected to have a hardness greater than or comparable to diamond. Since then, no unambiguous experimental evidence of their existence has been delivered. Here, we report the high-pressure high-temperature synthesis of the long-sought-after covalent carbon nitrides, tI14-C3N4, hP126-C3N4, and tI24-CN2, in laser-heated diamond anvil cells. Their structures were solved and refined using synchrotron single-crystal X-ray diffraction. In these solids, carbon atoms, all sp3-hybridized, and nitrogen atoms are fully saturated, forming four and three covalent bonds, respectively, leading to three-dimensional arrangements of corner-sharing CN4 tetrahedra. These carbon nitrides are ultra-incompressible, with hP126-C3N4 and tI24-CN2 even rivalling diamond's incompressibility, and superhard. These novel compounds are recoverable to ambient conditions in crystalline form and chemically stable in air. Being wide-band gap semiconductors with intriguing features in their electronic structure, they are expected to exhibit multiple exceptional functionalities besides their mechanical properties, opening new perspectives for materials science.},

keywords = {Molecularly-Functionalized, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Strong light-matter interaction with self-hybridized bound states in the continuum in monolithic van der Waals metasurfaces},

author = {T Weber and L K\"{u}hner and L Sortino and A B Mhenni and N P Wilson and J K\"{u}hne and J J Finley and S A Maier and A Tittl},

url = {https://arxiv.org/abs/2209.01944},

doi = {https://doi.org/10.48550/arXiv.2209.01944},

year  = {2022},

date = {2022-09-05},

journal = {arXiv preprint arXiv:2209.01944},

abstract = {Photonic bound states in the continuum (BICs) are a standout nanophotonic platform for strong light-matter coupling with transition metal dichalcogenides (TMDCs), but have so far mostly been employed as all-dielectric metasurfaces with adjacent TMDC layers, incurring limitations related to strain, mode overlap, and material integration. In this work, we experimentally demonstrate for the first time asymmetry-dependent BIC resonances in 2D arrays of monolithic metasurfaces composed solely of the nanostructured bulk TMDC WS2 with BIC modes exhibiting sharp and tailored linewidths, ideal for selectively enhancing light-matter interactions. Geometrical variation enables the tuning of the BIC resonances across the exciton resonance in bulk WS2, revealing the strong-coupling regime with an anti-crossing pattern and a Rabi splitting of 116 meV. The precise control over the radiative loss channel provided by the BIC concept is harnessed to tailor the Rabi splitting via a geometrical asymmetry parameter of the metasurface. Crucially, the coupling strength itself can be controlled and is shown to be independent of material-intrinsic losses. Our BIC-driven monolithic metasurface platform can readily incorporate other TMDCs or excitonic materials to deliver previously unavailable fundamental insights and practical device concepts for polaritonic applications.},

keywords = {Molecularly-Functionalized, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {The Puzzling Question about the Origin of the Second Electron in the Molecular Photocatalytic Reduction of CO2},

author = {C Thomas and M Wittig and B Rieger},

url = {https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/cctc.202200841},

doi = {https://doi.org/10.1002/cctc.202200841},

issn = {1867-3880},

year  = {2022},

date = {2022-09-04},

journal = {ChemCatChem},

volume = {14},

number = {21},

pages = {e202200841},

abstract = {Abstract Herein, a new supramolecular photocatalyst RuRe3 containing three Re(dmb)CO3Cl (dmb=4,4‘-dimethyl-2,2‘-bipyridine) (Re) building blocks connected through an ethylene bridge to one [Ru(dmb)3]2+-unit (Ru) is presented. We investigated the photophysical properties of this novel tetranuclear complex and compared these to compounds with one (RuRe) and two (RuRe2) catalytic units. Under irradiation, all three photocatalysts exhibit high activity and photostability for the reduction of CO2 to CO, with RuRe3 achieving the highest turnover number (11800) reported to date for a Re(I)/Ru(II)-containing homogeneous catalyst. This tetranuclear complex is especially superior at small catalyst concentrations, which is attributed to an efficient second electron transfer via an intramolecular mechanism. Intermolecular electron transfer from small and mobile Re to RuRe motifs are found to also increase the catalytic performance of the system to a similar level (turnover number=12100). These synergistic effects are attributed to an improved catalytic cycle, stabilizing the bi- and tetrametallic complexes by providing the electrons quickly and effectively. Since the second electron provision is not finally clarified for molecular systems until today, our photocatalytic studies present important insights into this crucial step. Further, these investigations should be considered for the design and synthesis of new and efficient supramolecular CO2-reducing photocatalysts.},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {3D-Nanoprinted Antiresonant Hollow-Core Microgap Waveguide: An on-Chip Platform for Integrated Photonic Devices and Sensors},

author = {J B\"{u}rger and V Schalles and J Kim and B Jang and M Zeisberger and J Gargiulo and L De S. Menezes and M A Schmidt and S A Maier},

url = {https://doi.org/10.1021/acsphotonics.2c00725},

doi = {10.1021/acsphotonics.2c00725},

year  = {2022},

date = {2022-09-02},

journal = {ACS Photonics},

volume = {9},

number = {9},

pages = {3012-3024},

abstract = {Due to their unique capabilities, hollow-core waveguides are playing an increasingly important role, especially in meeting the growing demand for integrated and low-cost photonic devices and sensors. Here, we present the antiresonant hollow-core microgap waveguide as a platform for the on-chip investigation of light-gas interaction over centimeter-long distances. The design consists of hollow-core segments separated by gaps that allow external access to the core region, while samples with lengths up to 5 cm were realized on silicon chips through 3D-nanoprinting using two-photon absorption based direct laser writing. The agreement of mathematical models, numerical simulations and experiments illustrates the importance of the antiresonance effect in that context. Our study shows the modal loss, the effect of gap size and the spectral tuning potential, with highlights including extremely broadband transmission windows (\>200 nm), very high contrast resonance (\>60 dB), exceptionally high structural openness factor (18%) and spectral control by nanoprinting (control over dimensions with step sizes (i.e., increments) of 60 nm). The application potential was demonstrated in the context of laser scanning absorption spectroscopy of ammonia, showing diffusion speeds comparable to bulk diffusion and a low detection limit. Due to these unique properties, application of this platform can be anticipated in a variety of spectroscopy-related fields, including bioanalytics, environmental sciences, and life sciences.},

keywords = {Molecularly-Functionalized, Solid-Solid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Strong Polarization Dependent Nonlinear Excitation of a Perovskite Nanocrystal Monolayer on a Chiral Dielectric Nanoantenna Array},

author = {I Vin\c{c}on and F J Wendisch and D De Gregorio and S D Pritzl and Q A Akkerman and H Ren and L De S. Menezes and S A Maier and J Feldmann},

url = {https://doi.org/10.1021/acsphotonics.2c00159},

doi = {10.1021/acsphotonics.2c00159},

year  = {2022},

date = {2022-08-17},

journal = {ACS Photonics},

abstract = {With their unique optoelectronic properties, perovskite nanocrystals are highly advantageous semiconductor materials for tailored light applications including an interaction with circularly polarized light. Although chiral perovskite nanocrystals have been obtained by the adsorption of chiral molecules, their chiroptical response is still intrinsically weak. Alternatively, perovskites have been combined with artificial chiral surfaces demonstrating enhanced chiroptical responses. However, bulk perovskite films of considerable thickness were required, mitigating the perovskite’s photoluminescence efficiency and processability. Here we developed a hybrid system of a dielectric chiral nanoantenna array that was coated with a monolayer of cubic all-inorganic lead halide perovskite nanocrystals. By tuning the thickness of the perovskite film down to one monolayer of nanocrystals, we restricted the interactions exclusively to the near-field regime. The chiral surface built of z-shaped Si nanoantennas features pronounced chiral resonances in the visible to IR region. We demonstrate that the two-photon excited photoluminescence emission of the nanocrystals can be enhanced by up to one order of magnitude in this configuration. This emission increase is controllable by the choice of the excitation wavelength and polarization with an asymmetry in emission of up to 25% upon left and right circularly polarized illumination. Altogether, our findings demonstrate a pathway to an all-optical control and modulation of perovskite light emission via strong polarization sensitive light\textendashmatter interactions in the near-field, rendering this hybrid system interesting for sensing and display technologies.},

keywords = {Molecularly-Functionalized, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}