Publications

@article{,

title = {Advanced Bifunctional Oxygen Reduction and Evolution Electrocatalyst Derived from Surface-Mounted Metal-Organic Frameworks},

author = {W J Li and S Xue and S Watzele and S J Hou and J Fichtner and A L Semrau and L J Zhou and A Welle and A S Bandarenka and R A Fischer},

url = {\<Go to ISI\>://WOS:000509752400001},

doi = {10.1002/anie.201916507},

issn = {1433-7851},

year  = {2020},

date = {2020-01-08},

journal = {Angewandte Chemie-International Edition},

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

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Interplay of exciton annihilation and transport in fifth order electronic spectroscopy},

author = {C Heshmatpour and J Hauer and F Sanda},

url = {\<Go to ISI\>://WOS:000490758300009},

doi = {10.1016/j.chemphys.2019.110433},

issn = {0301-0104},

year  = {2020},

date = {2020-01-01},

journal = {Chemical Physics},

volume = {528},

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

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Ultrafast Single-Molecule Fluorescence Measured by Femtosecond Double-Pulse Excitation Photon Antibunching},

author = {J Schedlbauer and P Wilhelm and L Grabenhorst and M E Federl and B Lalkens and F Hinderer and U Scherf and S H\"{o}ger and P Tinnefeld and S Bange and J Vogelsang and J M Lupton},

url = {https://doi.org/10.1021/acs.nanolett.9b04354},

doi = {10.1021/acs.nanolett.9b04354},

issn = {1530-6984},

year  = {2019},

date = {2019-12-23},

journal = {Nano Letters},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Photophysical Effects behind the Efficiency of Hot Electron Injection in Plasmon-Assisted Catalysis: The Joint Role of Morphology and Composition},

author = {Y Negr\'{i}n-Montecelo and M Comesa\~{n}a-Hermo and L K Khorashad and A Sousa-Castillo and Z Wang and M P\'{e}rez-Lorenzo and T Liedl and A O Govorov and M A Correa-Duarte},

url = {https://doi.org/10.1021/acsenergylett.9b02478},

doi = {10.1021/acsenergylett.9b02478},

year  = {2019},

date = {2019-12-12},

journal = {ACS Energy Letters},

pages = {395-402},

keywords = {Foundry Inorganic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Quantum-Confinement-Enhanced Thermoelectric Properties in Modulation-Doped GaAs\textendashAlGaAs Core\textendashShell Nanowires},

author = {S Fust and A Faustmann and D J Carrad and J Bissinger and B Loitsch and M D\"{o}blinger and J Becker and G Abstreiter and J J Finley and G Koblm\"{u}ller},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adma.201905458},

doi = {10.1002/adma.201905458},

issn = {0935-9648},

year  = {2019},

date = {2019-12-09},

journal = {Advanced Materials},

volume = {32},

number = {4},

pages = {1905458},

abstract = {Abstract Nanowires (NWs) hold great potential in advanced thermoelectrics due to their reduced dimensions and low-dimensional electronic character. However, unfavorable links between electrical and thermal conductivity in state-of-the-art unpassivated NWs have, so far, prevented the full exploitation of their distinct advantages. A promising model system for a surface-passivated one-dimensional (1D)-quantum confined NW thermoelectric is developed that enables simultaneously the observation of enhanced thermopower via quantum oscillations in the thermoelectric transport and a strong reduction in thermal conductivity induced by the core\textendashshell heterostructure. High-mobility modulation-doped GaAs/AlGaAs core\textendashshell NWs with thin (sub-40 nm) GaAs NW core channel are employed, where the electrical and thermoelectric transport is characterized on the same exact 1D-channel. 1D-sub-band transport at low temperature is verified by a discrete stepwise increase in the conductance, which coincided with strong oscillations in the corresponding Seebeck voltage that decay with increasing sub-band number. Peak Seebeck coefficients as high as ≈65\textendash85 µV K−1 are observed for the lowest sub-bands, resulting in equivalent thermopower of S2σ ≈ 60 µW m−1 K−2 and S2G ≈ 0.06 pW K−2 within a single sub-band. Remarkably, these core\textendashshell NW heterostructures also exhibit thermal conductivities as low as ≈3 W m−1 K−1, about one order of magnitude lower than state-of-the-art unpassivated GaAs NWs.},

keywords = {Foundry Inorganic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Nonadiabatic Molecular Dynamics on Graphics Processing Units: Performance and Application to Rotary Molecular Motors},

author = {L D M Peters and J Kussmann and C Ochsenfeld},

url = {https://doi.org/10.1021/acs.jctc.9b00859},

doi = {10.1021/acs.jctc.9b00859},

issn = {1549-9618},

year  = {2019},

date = {2019-11-25},

journal = {Journal of Chemical Theory and Computation},

volume = {15},

number = {12},

pages = {6647-6659},

abstract = {Nonadiabatic molecular dynamics (NAMD) simulations of molecular systems require the efficient evaluation of excited-state properties, such as energies, gradients, and nonadiabatic coupling vectors. Here, we investigate the use of graphics processing units (GPUs) in addition to central processing units (CPUs) to efficiently calculate these properties at the time-dependent density functional theory (TDDFT) level of theory. Our implementation in the FermiONs++ program package uses the J-engine and a preselective screening procedure for the calculation of Coulomb and exchange kernels, respectively. We observe good speed-ups for small and large molecular systems (comparable to those observed in ground-state calculations) and reduced (down to sublinear) scaling behavior with respect to the system size (depending on the spatial locality of the investigated excitation). As a first illustrative application, we present efficient NAMD simulations of a series of newly designed light-driven rotary molecular motors and compare their S1 lifetimes. Although all four rotors show different S1 excitation energies, their ability to rotate upon excitation is conserved, making the series an interesting starting point for rotary molecular motors with tunable excitation energies.},

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

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Towards a transferable design of solid-state embedding models on the example of a rutile TiO2 (110) surface},

author = {M Kick and H Oberhofer},

url = {\<Go to ISI\>://WOS:000497760200011},

doi = {10.1063/1.5125204},

issn = {0021-9606},

year  = {2019},

date = {2019-11-14},

journal = {Journal of Chemical Physics},

volume = {151},

number = {18},

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

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Dibenzochrysene enables tightly controlled docking and stabilizes photoexcited states in dual-pore covalent organic frameworks},

author = {N Keller and T Sick and N N Bach and A Koszalkowski and J M Rotter and D D Medina and T Bein},

url = {http://dx.doi.org/10.1039/C9NR08007D},

doi = {10.1039/C9NR08007D},

issn = {2040-3364},

year  = {2019},

date = {2019-11-08},

urldate = {2019-11-08},

journal = {Nanoscale},

volume = {11},

number = {48},

pages = {23338-23345},

abstract = {Covalent organic frameworks (COFs), consisting of covalently connected organic building units, combine attractive features such as crystallinity, open porosity and widely tunable physical properties. For optoelectronic applications, the incorporation of heteroatoms into a 2D COF has the potential to yield desired photophysical properties such as lower band gaps, but can also cause lateral offsets of adjacent layers. Here, we introduce dibenzo[g,p]chrysene (DBC) as a novel building block for the synthesis of highly crystalline and porous 2D dual-pore COFs showing interesting properties for optoelectronic applications. The newly synthesized terephthalaldehyde (TA), biphenyl (Biph), and thienothiophene (TT) DBC-COFs combine conjugation in the a,b-plane with a tight packing of adjacent layers guided through the molecular DBC node serving as specific docking site for successive layers. The resulting DBC-COFs exhibit a hexagonal dual-pore kagome geometry, which is comparable to COFs containing another molecular docking site, namely 4,4′,4′′,4′′′-(ethylene-1,1,2,2-tetrayl)-tetraaniline (ETTA). In this context, the respective interlayer distances decrease from about 4.6 r{A} in ETTA-COFs to about 3.6 r{A} in DBC-COFs, leading to well-defined hexagonally faceted single crystals sized about 50\textendash100 nm. The TT DBC-COF features broad light absorption covering large parts of the visible spectrum, while Biph DBC-COF shows extraordinary excited state lifetimes exceeding 10 ns. In combination with the large number of recently developed linear conjugated building blocks, the new DBC tetra-connected node is expected to enable the synthesis of a large family of highly correlated and ordered 2D COFs with promising optoelectronic properties.},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Towards Reliable and Quantitative Surface-Enhanced Raman Scattering (SERS): From Key Parameters to Good Analytical Practice},

author = {S E J Bell and G Charron and E Cort\'{e}s and J Kneipp and De La M L Chapelle and J Langer and M Proch\'{a}zka and V Tran and S Schl\"{u}cker},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.201908154},

doi = {10.1002/anie.201908154},

issn = {1433-7851},

year  = {2019},

date = {2019-10-07},

urldate = {2019-10-07},

journal = {Angewandte Chemie International Edition},

volume = {59},

number = {14},

pages = {5454-5462},

abstract = {Abstract Experimental results obtained in different laboratories world-wide by researchers using surface-enhanced Raman scattering (SERS) can differ significantly. We, an international team of scientists with long-standing expertise in SERS, address this issue from our perspective by presenting considerations on reliable and quantitative SERS. The central idea of this joint effort is to highlight key parameters and pitfalls that are often encountered in the literature. To that end, we provide here a series of recommendations on: a) the characterization of solid and colloidal SERS substrates by correlative electron and optical microscopy and spectroscopy, b) on the determination of the SERS enhancement factor (EF), including suitable Raman reporter/probe molecules, and finally on c) good analytical practice. We hope that both newcomers and specialists will benefit from these recommendations to increase the inter-laboratory comparability of experimental SERS results and further establish SERS as an analytical tool.},

keywords = {Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Covalent Organic Framework Films through Electrophoretic Deposition\textemdashCreating Efficient Morphologies for Catalysis},

author = {J M Rotter and S Weinberger and J Kampmann and T Sick and M Shalom and T Bein and D D Medina},

url = {https://doi.org/10.1021/acs.chemmater.9b02286},

doi = {10.1021/acs.chemmater.9b02286},

issn = {0897-4756},

year  = {2019},

date = {2019-10-03},

urldate = {2019-10-03},

journal = {Chemistry of Materials},

volume = {31},

number = {24},

pages = {10008-10016},

abstract = {The ability to grow covalent organic framework (COF) films allows for studying their properties as solid layers and enables the incorporation of these materials into a variety of functional devices. Here, we report on the fabrication of COF films and coatings by electrophoretic deposition (EPD). We demonstrate that the EPD technique is suitable for depositing COFs featuring two- and three-dimensional structures linked by imine or boronate ester bonds, namely, BDT-ETTA COF, COF-300, and COF-5. For the deposition, COF nanoparticle suspensions are prepared by dispersing the as-synthesized bulk materials in solvents with low dielectric constants. Subsequently, two electrodes are immersed into the COF particle suspensions, and upon inducing electric fields ranging from 100 to 900 V cm\textendash1, COFs are deposited as films on the positively charged electrode. Through EPD, within 2 min, large-area films of up to 25 cm2 are obtained on smooth or corrugated surfaces. COF films prepared by EPD feature an inherent textural porosity and tunable thickness, demonstrated from 400 nm to 24 μm. By controlling the deposition parameters such as duration, particle concentration, and applied potential, deposits of precise thickness can be produced. Furthermore, codepositions of different COFs as well as COF/Pt nanoparticles from mixed suspensions are demonstrated. The film morphologies obtained by EPD are shown to be advantageous for catalysis, as demonstrated for sacrificial agent-free photoelectrochemical water reduction. Here, BDT-ETTA COF photocathodes show a strongly increased photocurrent density compared to the respective dense and oriented films. Typical BDT-ETTA COF/Pt nanoparticle hybrid films exhibit photocurrent densities of over 100 μA cm\textendash2. The rapid and scalable deposition of COF particles as films and coatings through EPD is a versatile addition to the toolbox of COF film fabrication techniques, allowing for tailoring COF film architectures for desired functionalities.},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Optical absorption of composition-tunable InGaAs nanowire arrays},

author = {J Treu and X Xu and K Ott and K Saller and G Abstreiter and J J Finley and G Koblm\"{u}ller},

url = {http://dx.doi.org/10.1088/1361-6528/ab3ef7},

doi = {10.1088/1361-6528/ab3ef7},

issn = {0957-4484 

1361-6528},

year  = {2019},

date = {2019-09-20},

journal = {Nanotechnology},

volume = {30},

number = {49},

pages = {495703},

abstract = {InGaAs nanowire (NW) arrays have emerged as important active materials in future photovoltaic and photodetector applications, due to their excellent electronic properties and tunable band gap. Here, we report a systematic investigation of the optical absorption characteristics of composition-tunable vertical InGaAs NW arrays. Using finite-difference time-domain simulations we first study the effect of variable composition (Ga-molar fraction) and NW array geometry (NW diameter, period, fill factor) on the optical generation rate. NWs with typical diameters in the range of ∼100\textendash250 nm lead to generation rates higher than the equivalent bulk case for moderate fill factors (NW period of ∼0.3\textendash0.8 μm), while slightly smaller fill factors and increased diameters are required to maintain high generation rates at increased Ga-molar fraction. The optical absorption was further measured using spectrally resolved ultraviolet\textendashvisible-near-infrared (UV\textendashvis-NIR) spectroscopy on NW arrays transferred to transparent substrates. Interestingly, large variations in Ga-molar fraction (0 \< x(Ga) \< 0.5) have a negligible influence, while minute changes in NW diameter of less than ±20 nm affect the absorption spectra very strongly, leading to pronounced shifts in the peak absorption energies by more than ∼700 meV. These results clearly highlight the much larger sensitivity of the optical absorption behavior to geometric parameters rather than to variations in the electronic band gap of the underlying NW array.},

keywords = {Foundry Inorganic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Directing Single-Molecule Emission with DNA Origami-Assembled Optical Antennas},

author = {K H\"{u}bner and M Pilo-Pais and F Selbach and T Liedl and P Tinnefeld and F D Stefani and G P Acuna},

url = {https://doi.org/10.1021/acs.nanolett.9b02886},

doi = {10.1021/acs.nanolett.9b02886},

issn = {1530-6984},

year  = {2019},

date = {2019-09-11},

urldate = {2019-09-11},

journal = {Nano Letters},

volume = {19},

number = {9},

pages = {6629-6634},

keywords = {Foundry Inorganic, Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {A highly crystalline anthracene-based MOF-74 series featuring electrical conductivity and luminescence},

author = {P I Scheurle and A M\"{a}hringer and A C Jakowetz and P Hosseini and A F Richter and G Wittstock and D D Medina and T Bein},

url = {http://dx.doi.org/10.1039/C9NR05431F},

doi = {10.1039/C9NR05431F},

issn = {2040-3364},

year  = {2019},

date = {2019-09-10},

journal = {Nanoscale},

volume = {11},

number = {43},

pages = {20949-20955},

abstract = {Recently, a small group of metal\textendashorganic frameworks (MOFs) has been discovered featuring substantial charge transport properties and electrical conductivity, hence promising to broaden the scope of potential MOF applications in fields such as batteries, fuel cells and supercapacitors. In combination with light emission, electroactive MOFs are intriguing candidates for chemical sensing and optoelectronic applications. Here, we incorporated anthracene-based building blocks into the MOF-74 topology with five different divalent metal ions, that is, Zn2+, Mg2+, Ni2+, Co2+ and Mn2+, resulting in a series of highly crystalline MOFs, coined ANMOF-74(M). This series of MOFs features substantial photoluminescence, with ANMOF-74(Zn) emitting across the whole visible spectrum. The materials moreover combine this photoluminescence with high surface areas and electrical conductivity. Compared to the original MOF-74 materials constructed from 2,5-dihydroxy terephthalic acid and the same metal ions Zn2+, Mg2+, Ni2+, Co2+ and Mn2+, we observed a conductivity enhancement of up to six orders of magnitude. Our results point towards the importance of building block design and the careful choice of the embedded MOF topology for obtaining materials with desired properties such as photoluminescence and electrical conductivity.},

keywords = {Foundry Inorganic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Particle-in-a-Frame Nanostructures with Interior Nanogaps},

author = {S Lee and J Kim and H Yang and E Cort\'{e}s and S Kang and S W Han},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.201908291},

doi = {https://doi.org/10.1002/anie.201908291},

issn = {1433-7851},

year  = {2019},

date = {2019-09-03},

journal = {Angewandte Chemie International Edition},

volume = {58},

number = {44},

pages = {15890-15894},

abstract = {Abstract Designing plasmonic hollow colloids with small interior nanogaps would allow structural properties to be exploited that are normally linked to an ensemble of particles but within a single nanoparticle. Now, a synthetic approach for constructing a new class of frame nanostructures is presented. Fine control over the galvanic replacement reaction of Ag nanoprisms with Au precursors gave unprecedented Au particle-in-a-frame nanostructures with well-defined sub-2 nm interior nanogaps. The prepared nanostructures exhibited superior performance in applications, such as plasmonic sensing and surface-enhanced Raman scattering, over their solid nanostructure and nanoframe counterparts. This highlights the benefit of their interior hot spots, which can highly promote and maximize the electric field confinement within a single nanostructure.},

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

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Introducing catalysis in photocatalysis: What can be understood from surface science studies of alcohol photoreforming on TiO2},

author = {C A Walenta and M Tschurl and U Heiz},

url = {\<Go to ISI\>://WOS:000482603900001},

doi = {10.1088/1361-648X/ab351a},

issn = {0953-8984},

year  = {2019},

date = {2019-08-23},

urldate = {2019-08-23},

journal = {Journal of Physics-Condensed Matter},

volume = {31},

number = {47},

keywords = {Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {From Optical to Chemical Hot Spots in Plasmonics},

author = {J Gargiulo and R Bert\'{e} and Y Li and S A Maier and E Cort\'{e}s},

url = {https://doi.org/10.1021/acs.accounts.9b00234},

doi = {10.1021/acs.accounts.9b00234},

issn = {0001-4842},

year  = {2019},

date = {2019-08-20},

journal = {Accounts of Chemical Research},

keywords = {Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Generation and Stabilization of Small Platinum Clusters Pt-12 +/- x Inside a Metal-Organic Framework},

author = {K Kratzl and T Kratky and S Gunther and O Tomanec and R Zboril and J Michalicka and J M Macak and M Cokoja and R A Fischer},

url = {\<Go to ISI\>://WOS:000484828900039},

doi = {10.1021/jacs.9b07083},

issn = {0002-7863},

year  = {2019},

date = {2019-08-09},

journal = {Journal of the American Chemical Society},

volume = {141},

number = {35},

pages = {13962-13969},

keywords = {Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Influence of Local Defects on the Dynamics of O-H Bond Breaking and Formation on a Magnetite Surface},

author = {A Bourgund and B A J Lechner and M Meier and C Franchini and G S Parkinson and U Heiz and F Esch},

url = {\<Go to ISI\>://WOS:000481568900054},

doi = {10.1021/acs.jpcc.9b05547},

issn = {1932-7447},

year  = {2019},

date = {2019-07-17},

urldate = {2019-07-17},

journal = {Journal of Physical Chemistry C},

volume = {123},

number = {32},

pages = {19742-19747},

keywords = {Foundry Inorganic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Distance Dependence of Single-Molecule Energy Transfer to Graphene Measured with DNA Origami Nanopositioners},

author = {I Kaminska and J Bohlen and S Rocchetti and F Selbach and G P Acuna and P Tinnefeld},

url = {https://doi.org/10.1021/acs.nanolett.9b00172},

doi = {10.1021/acs.nanolett.9b00172},

issn = {1530-6984},

year  = {2019},

date = {2019-07-10},

journal = {Nano Letters},

volume = {19},

number = {7},

pages = {4257-4262},

abstract = {Despite the thorough investigation of graphene since 2004, altering its surface chemistry and reproducible functionalization remain challenging. This hinders fabrication of more complex hybrid materials with controlled architectures, and as a consequence the development of sensitive and reliable sensors and biological assays. In this contribution, we introduce DNA origami structures as nanopositioners for placing single dye molecules at controlled distances from graphene. The measurements of fluorescence intensity and lifetime of single emitters carried out for distances ranging from 3 to 58 nm confirmed the d\textendash4 dependence of the excitation energy transfer to graphene. Moreover, we determined the characteristic distance for 50% efficiency of the energy transfer from single dyes to graphene to be 17.7 nm. Using pyrene molecules as a glue to immobilize DNA origami nanostructures of various shape on graphene opens new possibilities to develop graphene-based biophysics and biosensing.},

keywords = {Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Aspects of semiconductivity in soft, porous metal-organic framework crystals},

author = {C Muschielok and H Oberhofer},

url = {\<Go to ISI\>://WOS:000474214600025},

doi = {10.1063/1.5108995},

issn = {0021-9606},

year  = {2019},

date = {2019-07-03},

journal = {Journal of Chemical Physics},

volume = {151},

number = {1},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Excited State Conformations of Bridged and Unbridged Pyrene Excimers},

author = {S Reiter and M K Roos and R De Vivie-Riedle},

url = {\<Go to ISI\>://WOS:000487014600024},

doi = {10.1002/cptc.201900096},

issn = {2367-0932},

year  = {2019},

date = {2019-05-06},

journal = {Chemphotochem},

volume = {3},

number = {9},

pages = {881-888},

keywords = {Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Interchromophoric Interactions Determine the Maximum Brightness Density in DNA Origami Structures},

author = {T Schr\"{o}der and M B Scheible and F Steiner and J Vogelsang and P Tinnefeld},

url = {https://doi.org/10.1021/acs.nanolett.8b04845},

doi = {10.1021/acs.nanolett.8b04845},

issn = {1530-6984},

year  = {2019},

date = {2019-02-13},

urldate = {2019-02-13},

journal = {Nano Letters},

volume = {19},

number = {2},

pages = {1275-1281},

abstract = {An ideal point light source is as small and as bright as possible. For fluorescent point light sources, homogeneity of the light sources is important as well as that the fluorescent units inside the light source maintain their photophysical properties, which is compromised by dye aggregation. Here we propose DNA origami as a rigid scaffold to arrange dye molecules in a dense pixel array with high control of stoichiometry and dye\textendashdye interactions. In order to find the highest labeling density in a DNA origami structure without influencing dye photophysics, we alter the distance of two ATTO647N dyes in single base pair steps and probe the dye\textendashdye interactions on the single-molecule level. For small distances strong quenching in terms of intensity and fluorescence lifetime is observed. With increasing distance, we observe reduced quenching and molecular dynamics. However, energy transfer processes in the weak coupling regime still have a significant impact and can lead to quenching by singlet-dark-state-annihilation. Our study fills a gap of studying the interactions of dyes relevant for superresolution microscopy with dense labeling and for single-molecule biophysics. Incorporating these findings in a 3D DNA origami object will pave the way to bright and homogeneous DNA origami nanobeads.},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Cobalt-Catalyzed Electrophilic Aminations with Anthranils: An Expedient Route to Condensed Quinolines},

author = {J Li and E Tan and N Keller and Y-H Chen and P M Zehetmaier and A C Jakowetz and T Bein and P Knochel},

url = {https://doi.org/10.1021/jacs.8b11466},

doi = {10.1021/jacs.8b11466},

issn = {0002-7863},

year  = {2019},

date = {2019-01-09},

journal = {Journal of the American Chemical Society},

volume = {141},

number = {1},

pages = {98-103},

abstract = {The reaction of various organozinc pivalates with anthranils provides anilines derivatives, which cyclize under acidic conditions providing condensed quinolines. Using alkenylzinc pivalates, electron-rich arylzinc pivalates or heterocyclic zinc pivalates produces directly the condensed quinolines of which several structures belong to new heterocyclic scaffolds. These N-heterocycles are of particular interest for organic light emitting diodes with their high photoluminescence quantum yields and long exciton lifetimes as well as for hole-transporting materials in methylammonium lead iodide perovskites solar cells due to an optimal band alignment for holes and a large bandgap.},

keywords = {Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Enhancing photosynthesis at high light levels by adaptive laboratory evolution},

author = {M Dann and E M Ortiz and M Thomas and A Guljamow and M Lehmann and H Schaefer and D Leister},

url = {\<Go to ISI\>://WOS:000646516500001},

doi = {10.1038/s41477-021-00904-2},

issn = {2055-026X},

journal = {Nature Plants},

volume = {7},

number = {5},

pages = {681-+},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Probing the micro- and nanoscopic properties of dental materials using infrared spectroscopy: A proof-of-principle study},

author = {M Beddoe and T G\"{o}lz and M Barkey and E Bau and M Godejohann and S A Maier and F Keilmann and M Moldovan and D Prodan and N Ilie and A Tittl},

url = {https://www.sciencedirect.com/science/article/pii/S1742706123004026},

doi = {https://doi.org/10.1016/j.actbio.2023.07.017},

issn = {1742-7061},

journal = {Acta Biomaterialia},

volume = {168},

pages = {309-322},

abstract = {The preservation of oral health over a person's lifespan is a key factor for a high quality of life. Sustaining oral health requires high-end dental materials with a plethora of attributes such as durability, non-toxicity and ease of application. The combination of different requirements leads to increasing miniaturization and complexity of the material components such as the composite and adhesives, which makes the precise characterization of the material blend challenging. Here, we demonstrate how modern IR spectroscopy and imaging from the micro- to the nanoscale can provide insights on the chemical composition of the different material sections of a dental filling. We show how the recorded IR-images can be used for a fast and non-destructive porosity determination of the studied adhesive. Furthermore, the nanoscale study allows precise assessment of glass cluster structures and distribution within their characteristic organically modified ceramic (ORMOCER) matrix and an assessment of the interface between the composite and adhesive material. For the study we used a Fourier-Transform-IR (FTIR) microscope and a quantum cascade laser-based IR-microscope (QCL-IR) for the microscale analysis and a scattering-type scanning near-field optical microscopy (s-SNOM) for the nanoscale analysis. The paper ends with an in-depth discussion of the strengths and weaknesses of the different imaging methods to give the reader a clear picture for which scientific question the microscopes are best suited for. Statement of significance Modern resin-based composites for dental restoration are complex multi-compound materials. In order to improve these high-end materials, it is important to investigate the molecular composition and morphology of the different parts. An emergent method to characterize these materials is infrared spectroscopic imaging, which combines the strength of infrared spectroscopy and an imaging approach known from optical microscopy. In this work, three state of the art methods are compared for investigating a dental filling including FTIR- and quantum cascade laser IR-imaging microscopy for the microscale and scattering-type scanning near-field optical microscopy for the nanoscale.},

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

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Optoelectronic perovskite film characterization via machine vision},

author = {M Harth and L Vesce and I Kouroudis and M Stefanelli and A Di Carlo and A Gagliardi},

url = {https://www.sciencedirect.com/science/article/pii/S0038092X23004656},

doi = {https://doi.org/10.1016/j.solener.2023.111840},

issn = {0038-092X},

journal = {Solar Energy},

volume = {262},

pages = {111840},

abstract = {We present our research for fast and reliable extraction of bandgap and absorption quality values for triple-cation perovskite thin films from sample scans. Our approach leverages machine learning methods, namely convolutional neural networks, to perform regression tasks aimed at predicting the properties of interest. To this end, thin film samples were synthesized via blade-coating and their photoluminescence and ultraviolet\textendashvisible spectra collected, along with the film thickness. We propose a method of computing a dimensionless figure of merit we called the Area Under Absorption Coefficient (AUAC), its purpose being to qualitatively evaluate the absorption quality of perovskite films for use in photovoltaic modules. This work demonstrates the usability of simple imaging techniques to analyze experimental samples while requiring only a feasibly acquirable initial amount of data. Our reported method can help speed up time consuming material optimizations by reducing lab time spent on recurrent characterization, nicely synergizes with high throughput production lines and could be adapted for quick extraction of other optoelectrical quantities.},

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

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Mechanistic Insights into ZIF-8 Encapsulation of Atom-Precise Pt(M) Carbonyl Clusters},

author = {K L Kollmannsberger and Poonam and C Cesari and R Khare and T Kratky and M Boniface and O Tomanec and J Michali\v{c}ka and E Mosconi and A Gagliardi and S G\"{u}nther and W Kaiser and T Lunkenbein and S Zacchini and J Warnan and R A Fischer},

url = {https://doi.org/10.1021/acs.chemmater.3c00807},

doi = {10.1021/acs.chemmater.3c00807},

issn = {0897-4756},

journal = {Chemistry of Materials},

volume = {35},

number = {14},

pages = {5475-5486},

abstract = {Precisely designing metal nanoparticles (NPs) is the cornerstone for maximizing their efficiency in applications like catalysis or sensor technology. Metal\textendashorganic frameworks (MOFs) with their defined and tunable pore systems provide a confined space to host and stabilize small metal NPs. In this work, the MOF encapsulation of various atom-precise clusters following the bottle-around-ship approach is investigated, providing general insights into the scaffolding mechanism. Eleven carbonyl-stabilized Pt(M) (M = Co, Ni, Fe, and Sn) clusters are employed for the encapsulation in the zeolitic imidazolate framework (ZIF)-8. Infrared and UV/Vis spectroscopy, density functional theory, and ab initio molecular dynamics revealed structure\textendashencapsulation relationship guidelines. Thereby, cluster polarization, size, and composition were found to condition the scaffolding behavior. Encaging of [NBnMe3]2[Co8Pt4C2(CO)24] (Co8Pt4) is thus achieved as the first MOF-encapsulated bimetallic carbonyl cluster, Co8Pt4@ZIF-8, and is fully characterized including X-ray absorption near edge and extended X-ray absorption spectroscopy. ZIF-8 confinement not only promotes property changes, like the T-dependent magnetism, but it also further allows heat-induced ligand-stripping without altering the cluster size, enabling the synthesis of naked, heterometallic, close to atom-precise clusters.},

keywords = {Foundry Inorganic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Optimization of p-Type Cu2O Nanocube Photocatalysts Based on Electronic Effects},

author = {R Lin and H Chen and T Cui and Z Zhang and Q Zhou and L Nan and W-C Cheong and L Schr\"{o}ck and V Ramm and Q Ding and X Liang and S Saris and F J Wendisch and S A Maier and R A Fischer and Y Zhu and D Wang and E Cortes},

url = {https://doi.org/10.1021/acscatal.3c02710},

doi = {10.1021/acscatal.3c02710},

journal = {ACS Catalysis},

pages = {11352-11361},

abstract = {The size effect in semiconductor photocatalysis has been widely investigated but still remains elusive. Herein, employing p-type Cu2O nanocubes as the heterogeneous photocatalysts, we propose a feasible size optimization strategy to enhance the photocatalytic performance of semiconductors. With the size of Cu2O increasing from 2.5 nm (exciton Bohr radius) to 5 nm (twice the exciton Bohr radius), the corresponding calculated band gap of Cu2O decreases from 3.39 to 2.41 eV, indicating that controlling the size to above twice the exciton Bohr radius is vital for retaining the visible-light response of Cu2O. Based on the theoretical calculations and experimental measurements of the charge carrier dynamics, we found that the synthesized 30 nm Cu2O nanocubes have an electron diffusion length of 191 nm, while 229 nm Cu2O nanocubes show an electron diffusion length of 45 nm. An electron diffusion length larger than the semiconductor particle size lowers the electron\textendashhole recombination, resulting in a visible-light CO generation rate 23.4 times higher for the smaller Cu2O nanocubes than that for the larger ones. These results verify that confining Cu2O size to within the minority carrier diffusion length and above twice the exciton Bohr radius is a promising way to enhance Cu2O photocatalytic activity.},

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

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Active Loss Engineering in Vanadium Dioxide Based BIC Metasurfaces},

author = {A Aigner and F Ligmajer and K Rovensk\'{a} and J Holobr\'{a}dek and B Idesov\'{a} and S A Maier and A Tittl and L D S Menezes},

url = {https://arxiv.org/abs/2312.00547},

doi = {https://doi.org/10.48550/arXiv.2312.00547},

journal = {arXiv preprint arXiv:2312.00547},

abstract = {Metasurfaces have unlocked significant advancements across photonics, yet their efficient active control remains challenging. The active materials required often lack continuous tunability, exhibit inadequate refractive index (RI) changes, or suffer from high losses. These aspects pose an inherent limitation for resonance-shifting based switching: when RI changes are small, the resulting shift is also minor. Conversely, high RI changes typically come with high intrinsic losses necessitating broad modes because narrow ones cannot tolerate such losses. Therefore, larger spectral shifts are required to effectively detune the modes. This paper introduces a novel active metasurface approach that converts the constraint of high intrinsic losses into a beneficial feature. This is achieved by controlling the losses in a hybrid vanadium dioxide (VO2) - silicon metasurface, supporting symmetry-protected bound states in the continuum (BICs) within the infrared spectrum. By leveraging the temperature-controlled losses in VO2 and combining them with the inherent far-field-coupling tunability of BICs, we gain unprecedented precision in independently controlling both the radiative and nonradiative losses of the resonant system. Our dual-control mechanism allows us to optimize our metasurfaces and we experimentally demonstrate quality factors above 200, a maximum reflectance amplitude of 90%, a relative switching contrast of 78%, and continuous tuning from under- to over-coupling within the infrared spectral range. This study provides a foundation for experimentally and technologically simple, fine-tunable, active metasurfaces for applications ranging from molecular sensors to filters and optical modulators.},

keywords = {Foundry Inorganic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Continuous spectral and coupling-strength encoding with dual-gradient metasurfaces},

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

url = {https://arxiv.org/abs/2312.05600},

doi = {https://doi.org/10.48550/arXiv.2312.05600},

journal = {arXiv preprint arXiv:2312.05600},

abstract = {Optical metasurfaces excel at enhancing and controlling light-matter interactions, which are primarily dictated by two factors: the spectral overlap of the resonances with target excitations in the material and the coupling-strength between them, where resonance linewidth and localized field enhancement are the governing influences. Current metasurface designs are limited to sampling a few discrete points within this vast 2D interaction parameter space or have varied only a single parameter. Symmetry-protected bound states in the continuum (BICs) allow precise control over the wavelength and linewidth of individual resonances, but rely on large arrangements of identical unit cells, limiting the continuous mapping of the parameter space. Therefore, optical platforms that concurrently probe the spectral and coupling parameters, so far, remained elusive. Here, we introduce the concept of dual-gradient metasurfaces for the continuous and simultaneous encoding of the spectral and coupling-strength of light-matter interactions, enabled by smooth local variations of the unit cell parameters. Contrary to conventional understanding, we demonstrate that BICs can be excited in such non-periodic systems provided the parameter variations are sufficiently small. Our dual-gradient metasurface exhibits an extraordinary resonance density, with each unit cell supporting a unique mode. This results in up to 27,500 distinct modes, all contained within a compact footprint. We apply this technology to surface-enhanced molecular sensing, capturing not only the spectral fingerprint of molecules but also unveiling an additional coupling-based dimension of spectroscopic data. This advancement in metasurface design paves the way for generalized light-matter coupling with metasurfaces, with applications ranging from on-chip spectrometer, to chirality encoding and AI-driven biochemical spectroscopy.},

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

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Platinum-DNA Origami Hybrid Structures in Concentrated Hydrogen Peroxide},

author = {M Alarc\'{o}n-Correa and L Kilwing and F Peter and T Liedl and P Fischer},

url = {https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/cphc.202300294},

doi = {https://doi.org/10.1002/cphc.202300294},

issn = {1439-4235},

journal = {ChemPhysChem},

volume = {24},

number = {22},

pages = {e202300294},

abstract = {Abstract The DNA origami technique allows fast and large-scale production of DNA nanostructures that stand out with an accurate addressability of their anchor points. This enables the precise organization of guest molecules on the surfaces and results in diverse functionalities. However, the compatibility of DNA origami structures with catalytically active matter, a promising pathway to realize autonomous DNA machines, has so far been tested only in the context of bio-enzymatic activity, but not in chemically harsh reaction conditions. The latter are often required for catalytic processes involving high-energy fuels. Here, we provide proof-of-concept data showing that DNA origami structures are stable in 5 % hydrogen peroxide solutions over the course of at least three days. We report a protocol to couple these to platinum nanoparticles and show catalytic activity of the hybrid structures. We suggest that the presented hybrid structures are suitable to realize catalytic nanomachines combined with precisely engineered DNA nanostructures.},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Pixelated high-Q metasurfaces for in-situ biospectroscopy and AI-enabled classification of lipid membrane photoswitching dynamics},

author = {M Barkey and R B\"{u}chner and A Wester and S D Pritzl and M Makarenko and Q Wang and T Weber and D Trauner and S A Maier and A Fratalocchi},

url = {https://arxiv.org/abs/2308.15644},

doi = {https://doi.org/10.48550/arXiv.2308.15644},

journal = {arXiv preprint arXiv:2308.15644},

abstract = {Nanophotonic devices excel at confining light into intense hot spots of the electromagnetic near fields, creating unprecedented opportunities for light-matter coupling and surface-enhanced sensing. Recently, all-dielectric metasurfaces with ultrasharp resonances enabled by photonic bound states in the continuum have unlocked new functionalities for surface-enhanced biospectroscopy by precisely targeting and reading out molecular absorption signatures of diverse molecular systems. However, BIC-driven molecular spectroscopy has so far focused on endpoint measurements in dry conditions, neglecting the crucial interaction dynamics of biological systems. Here, we combine the advantages of pixelated all-dielectric metasurfaces with deep learning-enabled feature extraction and prediction to realize an integrated optofluidic platform for time-resolved in-situ biospectroscopy. Our approach harnesses high-Q metasurfaces specifically designed for operation in a lossy aqueous environment together with advanced spectral sampling techniques to temporally resolve the dynamic behavior of photoswitchable lipid membranes. Enabled by a software convolutional neural network, we further demonstrate the real-time classification of the characteristic cis and trans membrane conformations with 98% accuracy. Our synergistic sensing platform incorporating metasurfaces, optofluidics, and deep learning opens exciting possibilities for studying multi-molecular biological systems, ranging from the behavior of transmembrane proteins to the dynamic processes associated with cellular communication.},

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

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Photo-induced enhanced Raman spectroscopy as a probe for photocatalytic surfaces},

author = {S Ben-Jaber and D Glass and T Brick and S A Maier and I P Parkin and E Cort\'{e}s and W J Peveler and R Quesada-Cabrera},

url = {https://royalsocietypublishing.org/doi/abs/10.1098/rsta.2022.0343},

doi = {doi:10.1098/rsta.2022.0343},

journal = {Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences},

volume = {381},

number = {2259},

pages = {20220343},

abstract = {Photo-induced enhanced Raman spectroscopy (PIERS) has emerged as a highly sensitive surface-enhanced Raman spectroscopy (SERS) technique for the detection of ultra-low concentrations of organic molecules. The PIERS mechanism has been largely attributed to UV-induced formation of surface oxygen vacancies (Vo) in semiconductor materials, although alternative interpretations have been suggested. Very recently, PIERS has been proposed as a surface probe for photocatalytic materials, following Vo formation and healing kinetics. This work establishes comparison between PIERS and Vo-induced SERS approaches in defected noble-metal-free titanium dioxide (TiO2-x) films to further confirm the role of Vo in PIERS. Upon application of three post-treatment methods (namely UV-induction, vacuum annealing and argon etching), correlation of Vo kinetics and distribution could be established. A proposed mechanism and further discussion on PIERS as a probe to explore photocatalytic materials are also presented. This article is part of the theme issue ‘Exploring the length scales, timescales and chemistry of challenging materials (Part 2)’.},

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

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Metallic and All-Dielectric Metasurfaces Sustaining Displacement-Mediated Bound States in the Continuum},

author = {L M Berger and M Barkey and S A Maier and A Tittl},

url = {https://arxiv.org/abs/2306.00591},

doi = {https://doi.org/10.48550/arXiv.2306.00591},

journal = {arXiv preprint arXiv:2306.00591},

abstract = {Bound states in the continuum (BICs) are localized electromagnetic modes within the continuous spectrum of radiating waves. Due to their infinite lifetimes without radiation losses, BICs are driving research directions in lasing, non-linear optical processes, and sensing. However, conventional methods for converting BICs into leaky resonances, or quasi-BICs, with high-quality factors typically rely on breaking the in-plane inversion symmetry of the metasurface and often result in resonances that are strongly dependent on the angle of the incident light, making them unsuitable for many practical applications. Here, we numerically analyze and experimentally demonstrate an emerging class of BIC-driven metasurfaces, where the coupling to the far field is controlled by the displacement of individual resonators. In particular, we investigate both all-dielectric and metallic as well as positive and inverse displacement-mediated metasurfaces sustaining angular-robust quasi-BICs in the mid-infrared spectral region. We explore their behavior with changes in the incidence angle of illumination and experimentally show their superior performance compared to two conventional alternatives: silicon-based tilted ellipses and cylindrical nanoholes in gold. We anticipate our findings to open exciting perspectives for bio-sensing, conformal optical devices, and photonic devices using focused light.},

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

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Annealing-Free Ohmic Contacts to n-Type GaN via Hydrogen Plasma-Assisted Atomic Layer Deposition of Sub-Nanometer AlOx},

author = {M Christis and A Henning and J D Bartl and A Zeidler and B Rieger and M Stutzmann and I D Sharp},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/admi.202300758},

doi = {https://doi.org/10.1002/admi.202300758},

issn = {2196-7350},

journal = {Advanced Materials Interfaces},

volume = {n/a},

number = {n/a},

pages = {2300758},

abstract = {Abstract A plasma-assisted atomic layer deposition (PE-ALD) process is reported for creating ohmic contacts to n-type GaN that combines native oxide reduction, near-surface doping, and encapsulation of GaN in a single processing step, thereby eliminating the need for both wet chemical etching of the native oxide before metallization and thermal annealing after contact formation. Repeated ALD cycling of trimethyl aluminum (TMA) and high-intensity hydrogen (H2) plasma results in the deposition of a sub-nanometer-thin (≈8 r{A}) AlOx layer via the partial transformation of the GaN surface oxide into AlOx. Hydrogen plasma-induced nitrogen vacancies in the near-surface region of GaN serve as shallow donors, promoting efficient out-of-plane electrical transport. Subsequent metallization with a Ti/Al/Ti/Au stack results in low contact resistance, ohmic behavior, and smooth morphology without requiring annealing. This electrical contracting approach thus meets the thermal budget requirements for Si-based complementary metal\textendashoxide\textendashsemiconductor structures and can facilitate the design and fabrication of advanced GaN-on-Si heterodevices.},

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

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Downsizing Porphyrin Covalent Organic Framework Particles Using Protected Precursors for Electrocatalytic CO2 Reduction},

author = {K Endo and A Raza and L Yao and S Van Gele and A Rodr\'{i}guez-Camargo and H Vignolo-Gonz\'{a}lez and L Grunenberg and B Lotsch},

url = {https://chemrxiv.org/engage/chemrxiv/article-details/64d12052dfabaf06ffe07a6d},

doi = {10.26434/chemrxiv-2023-skm06},

abstract = {Covalent organic frameworks (COFs) are promising electrocatalyst platforms owing to their designability, porosity, and stability. Recently, COFs with various chemical structures were developed as efficient electrochemical CO2 reduction catalysts. However, controlling the morphology of COF catalysts remains a challenge, which can limit their electrocatalytic performance even if the chemical structure is optimally designed. Especially, while metalated porphyrinoids show great promise as catalytically active COF building blocks, their intermolecular stacking and coordination interactions make it difficult to conduct solution-based COF synthesis which can control the particle size dominated by the aggregation of crystallites. In this work, we report a new synthetic methodology for rationally downsized COF catalyst particles, where a tritylated amine is employed as a novel protected precursor for COF synthesis. Trityl protection provides high solubility to a representative cobalt porphyrin precursor, while its deprotection proceeds in situ under typical solvothermal COF synthesis conditions. This colloidal deprotection\textendashpolycondensation process yields smaller COF particles with less crystallite aggregation than a conventional synthesis, maintaining crystallinity and porosity. The downsized COF particles exhibit superior catalytic performance in electrochemical CO2 reduction, with higher CO production rate and faradaic efficiency with similar stability compared to conventional COF particles. The improved performance of downsized COF particles is attributed to the higher contact area with a conductive agent. This study provides a strategy for the preparation of COF electrocatalysts with controlled morphology and enhanced performance and also reveals an important factor in the evaluation of COF electrocatalysts.},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Spatial Distributions of Single-Molecule Reactivity in Plasmonic Catalysis},

author = {S Ezendam and J Gargiulo and A Sousa-Castillo and J B Lee and Y S Nam and S A Maier and E Cort\'{e}s},

url = {https://doi.org/10.1021/acsnano.3c07833},

doi = {10.1021/acsnano.3c07833},

issn = {1936-0851},

journal = {ACS Nano},

abstract = {Plasmonic catalysts have the potential to accelerate and control chemical reactions with light by exploiting localized surface plasmon resonances. However, the mechanisms governing plasmonic catalysis are not simple to decouple. Several plasmon-derived phenomena, such as electromagnetic field enhancements, temperature, or the generation of charge carriers, can affect the reactivity of the system. These effects are convoluted with the inherent (nonplasmonic) catalytic properties of the metal surface. Disentangling these coexisting effects is challenging but is the key to rationally controlling reaction pathways and enhancing reaction rates. This study utilizes super-resolution fluorescence microscopy to examine the mechanisms of plasmonic catalysis at the single-particle level. The reduction reaction of resazurin to resorufin in the presence of Au nanorods coated with a porous silica shell is investigated in situ. This allows the determination of reaction rates with a single-molecule sensitivity and subparticle resolution. By variation of the irradiation wavelength, it is possible to examine two different regimes: photoexcitation of the reactant molecules and photoexcitation of the nanoparticle’s plasmon resonance. In addition, the measured spatial distribution of reactivity allows differentiation between superficial and far-field effects. Our results indicate that the reduction of resazurin can occur through more than one reaction pathway, being most efficient when the reactant is photoexcited and is in contact with the Au surface. In addition, it was found that the spatial distribution of enhancements varies, depending on the underlying mechanism. These findings contribute to the fundamental understanding of plasmonic catalysis and the rational design of future plasmonic nanocatalysts.},

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

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Anti Stokes Thermometry of Plasmonic Nanoparticle Arrays},

author = {S Ezendam and L Nan and I L Violi and S A Maier and E Cort\'{e}s and G Baffou and J Gargiulo},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adom.202301496},

doi = {https://doi.org/10.1002/adom.202301496},

issn = {2195-1071},

journal = {Advanced Optical Materials},

volume = {n/a},

number = {n/a},

pages = {2301496},

abstract = {Abstract Metallic nanoparticles possess strong photothermal responses, especially when illuminated as ensembles due to collective effects. However, accurately quantifying the temperature increase remains a significant challenge, impeding progress in several applications. Anti Stokes thermometry offers a promising solution by enabling direct and non-invasive temperature measurements of the metal without the need for labeling or prior calibration. While Anti Stokes thermometry is successfully applied to individual nanoparticles, its potential to study light-to-heat conversion with plasmonic ensembles remains unexplored. In this study, the theoretical framework and the conditions that must be fulfilled for applying Anti Stokes thermometry to ensembles of nanoparticles are discussed. Then, this technique is implemented to measure the light-induced heating of square arrays of Au nanodisks. The obtained temperature measurements are validated using wavefront microscopy, demonstrating excellent agreement between the two thermometry methods. These results showcase the extension of Anti Stokes thermometry to plasmonic ensembles, highlighting its potential for implementation in the diverse photothermal applications involving these systems.},

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

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {The Role of Electrolytes in the Relaxation of Near-Surface Spin Defects in Diamond},

author = {F A Freire-Moschovitis and R Rizzato and A Pershin and M R Schepp and R D Allert and L M Todenhagen and M S Brandt and A Gali and D B Bucher},

url = {https://doi.org/10.1021/acsnano.3c01298},

doi = {10.1021/acsnano.3c01298},

issn = {1936-0851},

journal = {ACS Nano},

volume = {17},

number = {11},

pages = {10474-10485},

abstract = {Quantum sensing with spin defects in diamond, such as the nitrogen vacancy (NV) center, enables the detection of various chemical species on the nanoscale. Molecules or ions with unpaired electronic spins are typically probed by their influence on the NV center’s spin relaxation. Whereas it is well-known that paramagnetic ions reduce the NV center’s relaxation time (T1), here we report on the opposite effect for diamagnetic ions. We demonstrate that millimolar concentrations of aqueous diamagnetic electrolyte solutions increase the T1 time of near-surface NV center ensembles compared to pure water. To elucidate the underlying mechanism of this surprising effect, single and double quantum NV experiments are performed, which indicate a reduction of magnetic and electric noise in the presence of diamagnetic electrolytes. In combination with ab initio simulations, we propose that a change in the interfacial band bending due to the formation of an electric double layer leads to a stabilization of fluctuating charges at the interface of an oxidized diamond. This work not only helps to understand noise sources in quantum systems but could also broaden the application space of quantum sensors toward electrolyte sensing in cell biology, neuroscience, and electrochemistry.},

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

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Impact of bimetallic interface design on heat generation in plasmonic Au/Pd nanostructures studied by single-particle thermometry},

author = {J Gargiulo and M Herran and I L Violi and A Sousa-Castillo and L P Martinez and S Ezendam and M Barella and H Giesler and R Grzeschik and S Schl\"{u}cker and S A Maier and F D Stefani and E Cort\'{e}s},

url = {https://doi.org/10.1038/s41467-023-38982-9},

doi = {10.1038/s41467-023-38982-9},

issn = {2041-1723},

journal = {Nature Communications},

volume = {14},

number = {1},

pages = {3813},

abstract = {Localized surface plasmons are lossy and generate heat. However, accurate measurement of the temperature of metallic nanoparticles under illumination remains an open challenge, creating difficulties in the interpretation of results across plasmonic applications. Particularly, there is a quest for understanding the role of temperature in plasmon-assisted catalysis. Bimetallic nanoparticles combining plasmonic with catalytic metals are raising increasing interest in artificial photosynthesis and the production of solar fuels. Here, we perform single-particle thermometry measurements to investigate the link between morphology and light-to-heat conversion of colloidal Au/Pd nanoparticles with two different configurations: core\textendashshell and core-satellite. It is observed that the inclusion of Pd as a shell strongly reduces the photothermal response in comparison to the bare cores, while the inclusion of Pd as satellites keeps photothermal properties almost unaffected. These results contribute to a better understanding of energy conversion processes in plasmon-assisted catalysis.},

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

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Plasmonic bimetallic two-dimensional supercrystals for H2 generation},

author = {M Herran and S Juergensen and M Kessens and D Hoeing and A K\"{o}ppen and A Sousa-Castillo and W J Parak and H Lange and S Reich and F Schulz and E Cort\'{e}s},

url = {https://doi.org/10.1038/s41929-023-01053-9},

doi = {10.1038/s41929-023-01053-9},

issn = {2520-1158},

journal = {Nature Catalysis},

volume = {6},

number = {12},

pages = {1205-1214},

abstract = {Sunlight-driven H2 generation is a central technology to tackle our impending carbon-based energy collapse. Colloidal photocatalysts consisting of plasmonic and catalytic nanoparticles are promising for H2 production at solar irradiances, but their performance is hindered by absorption and multiscattering events. Here we present a two-dimensional bimetallic catalyst by incorporating platinum nanoparticles into a well-defined supercrystal of gold nanoparticles. The bimetallic supercrystal exhibited an H2 generation rate of $$139,mathrmmmol,mathrmg_mathrmcat^-1,mathrmh^-1$$via formic acid dehydrogenation under visible light illumination and solar irradiance. This configuration makes it possible to study the interaction between the two metallic materials and the influence of this in catalysis. We observe a correlation between the intensity of the electric field in the hotspots and the boosted catalytic activity of platinum nanoparticles, while identifying a minor role of heat and gold-to-platinum charge transfer in the enhancement. Our results demonstrate the benefits of two-dimensional configurations with optimized architecture for liquid-phase photocatalysis.},

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

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Cu/Ag\textendashSb\textendashI Rudorffite Thin Films for Photovoltaic Applications},

author = {R Hooijer and A Weis and W Kaiser and A Biewald and P D\"{o}rflinger and C Maheu and O Arsatiants and D Helminger and V Dyakonov and A Hartschuh and E Mosconi and F De Angelis and T Bein},

url = {https://doi.org/10.1021/acs.chemmater.3c01837},

doi = {10.1021/acs.chemmater.3c01837},

issn = {0897-4756},

journal = {Chemistry of Materials},

volume = {35},

number = {23},

pages = {9988-10000},

abstract = {In the search for lead-free perovskites, silver pnictohalides recently gained attention as novel perovskite-inspired materials for photovoltaics due to their high stability, low toxicity, and promising early efficiencies, especially for indoor applications. Recent research on such “rudorffites” mainly addresses silver bismuth iodides (Ag\textendashBi\textendashI), while their antimony analogues are hardly investigated due to intrinsic challenges in the synthesis of Sb-based thin films. Here, we establish a synthetic route to prepare Ag\textendashSb\textendashI thin films by employing thiourea as a Lewis-base additive. Thin film morphologies were further optimized by alloying them with Cu, resulting in solar cells with an improved power conversion efficiency of 0.7% by reducing undesired side phases. Density functional theory calculations and optical characterization methods support the incorporation of Cu into a Cu1\textendashxAgxSbI4 phase, keeping the overall stoichiometry and band gap virtually unchanged upon alloying. Our results further reveal the detrimental role of Ag point defects representing trap states in the band gap, being responsible for low open-circuit voltages and subgap absorption and emission features. Moreover, additional minor amounts of Bi are shown to boost the efficiency and stabilize the performance over a wider compositional range. Despite the remaining challenges regarding device performance, we demonstrate a strong increase in external quantum efficiency when reducing the light intensity, highlighting the potential of Ag\textendashSb\textendashI rudorffites for indoor photovoltaics.},

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

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Identifying the active species in a cobalt-based covalent organic framework for the electrochemical oxygen evolution reaction},

author = {P Hosseini and A Rodr\'{i}guez-Camargo and L Yao and B Lotsch and K Tschulik},

url = {https://chemrxiv.org/engage/chemrxiv/article-details/650cfd18b927619fe79761cb},

doi = {10.26434/chemrxiv-2023-7dl21},

abstract = {While considerable efforts have been devoted to developing functionalized covalent organic frameworks (COFs) as oxygen evolution electrocatalysts in recent years, studies related to the identification of the true catalytically active species for the oxygen evolution reaction (OER) remain lacking in the field. In this work, we investigated the active species of a cobalt-functionalized COF (TpBpy-Co) as electrochemical OER catalyst through a series of electrochemical measurements and post-electrolysis characterizations. Our results demonstrate that Co(II) ions, coordinated to the COF backbone, are transformed to cobalt-based nanoparticles when exposing TpBpy-Co to alkaline media. These nanoparticles act as the true active species for oxygen evolution. It remains unclear whether intact TpBpy-Co acts as a secondary catalytic species, due to its structural instability in alkaline electrolyte and its inferred lower catalytic activity compared to cobalt-based nanoparticles. Our results highlight that caution is warranted when identifying the active species for COF electrocatalysts formed under catalyst working conditions. Specifically, strong coordination between COFs and metal centers under electrochemical operation conditions is crucial to avoid unintended transformation of COF electrocatalysts. Our study thus contributes to the rational development of earth-abundant COF OER catalysts for the production of green hydrogen from renewable resources.},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Photovoltage and Photocurrent Absorption Spectra of Sulfur Vacancies Locally Patterned in Monolayer MoS2},

author = {A H\"{o}tger and W M\"{a}nner and T Amit and D Hernang\'{o}mez-P\'{e}rez and T Taniguchi and K Watanabe and U Wurstbauer and J J Finley and S Refaely-Abramson and C Kastl and A W Holleitner},

url = {https://doi.org/10.1021/acs.nanolett.3c03517},

doi = {10.1021/acs.nanolett.3c03517},

issn = {1530-6984},

journal = {Nano Letters},

abstract = {We report on the optical absorption characteristics of selectively positioned sulfur vacancies in monolayer MoS2, as observed by photovoltage and photocurrent experiments in an atomistic vertical tunneling circuit at cryogenic and room temperature. Charge carriers are resonantly photoexcited within the defect states before they tunnel through an hBN tunneling barrier to a graphene-based drain contact. Both photovoltage and photocurrent characteristics confirm the optical absorption spectrum as derived from ab initio GW and Bethe\textendashSalpeter equation approximations. Our results reveal the potential of single-vacancy tunneling devices as atomic-scale photodiodes.},

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

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Semiconductor Metasurfaces for Surface-enhanced Raman Scattering},

author = {H Hu and A K Pal and A Berestennikov and T Weber and A Stefancu and E Cortes and S A Maier and A Tittl},

url = {https://arxiv.org/abs/2309.10732},

doi = {https://doi.org/10.48550/arXiv.2309.10732},

journal = {arXiv preprint arXiv:2309.10732},

abstract = {Semiconductor-based surface-enhanced Raman spectroscopy (SERS) substrates, as a new frontier in the field of SERS, are hindered by their poor electromagnetic field confinement, and weak light-matter interaction. Metasurfaces, a class of 2D artificial materials based on the electromagnetic design of nanophotonic resonators, enable strong electromagnetic field enhancement and optical absorption engineering for a wide range of semiconductor materials. However, the engineering of semiconductor substrates into metasurfaces for improving SERS activity remains underexplored. Here, we develop an improved SERS metasurface platform that leverages the combination of titanium oxide (TiO2) and the emerging physical concept of optical bound states in the continuum (BICs) to boost the Raman emission. Moreover, fine-tuning of BIC-assisted resonant absorption offers a pathway for maximizing the photoinduced charge transfer effect (PICT) in SERS. We achieve ultrahigh values of BIC-assisted electric field enhancement (|E/E0|^2 ~ 10^3), challenging the preconception of weak electromagnetic (EM) field enhancement on semiconductor SERS substrates. Our BIC-assisted TiO2 metasurface platform offers a new dimension in spectrally-tunable SERS with earth-abundant and bio-compatible semiconductor materials, beyond the traditional plasmonic ones.},

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

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Theory of Hot-Carrier Generation in Bimetallic Plasmonic Catalysts},

author = {H Jin and M Herran and E Cort\'{e}s and J Lischner},

url = {https://doi.org/10.1021/acsphotonics.3c00715},

doi = {10.1021/acsphotonics.3c00715},

journal = {ACS Photonics},

volume = {10},

number = {10},

pages = {3629-3636},

abstract = {Bimetallic nanoreactors in which a plasmonic metal is used to funnel solar energy toward a catalytic metal have recently been studied experimentally, but a detailed theoretical understanding of these systems is lacking. Here, we present theoretical results of hot-carrier generation rates of different Au\textendashPd nanoarchitectures. In particular, we study spherical core\textendashshell nanoparticles with a Au core and a Pd shell as well as antenna\textendashreactor systems consisting of a large Au nanoparticle that acts as an antenna and a smaller Pd satellite nanoparticle separated by a gap. In addition, we investigate an antenna\textendashreactor system in which the satellite is a core\textendashshell nanoparticle. Hot-carrier generation rates are obtained from an atomistic quantum-mechanical modeling technique which combines a solution of Maxwell’s equation with a tight-binding description of the nanoparticle electronic structure. We find that antenna\textendashreactor systems exhibit significantly higher hot-carrier generation rates in the catalytic material than the core\textendashshell system as a result of strong electric field enhancements associated with the gap between the antenna and the satellite. For these systems, we also study the dependence of the hot-carrier generation rate on the size of the gap, the radius of the antenna nanoparticle, and the direction of light polarization. Overall, we find a strong correlation between the calculated hot-carrier generation rates and the experimentally measured chemical activity for the different Au\textendashPd photocatalysts. Our insights pave the way toward a microscopic understanding of hot-carrier generation in heterogeneous nanostructures for photocatalysis and other energy-conversion applications.},

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

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Study on the properties of wafer-scale grown MoS2 deposited via thermally induced chemical vapor deposition with Mo(CO)6 and H2S precursors},

author = {A Klumpp and R Hooijer and N Kr\"{u}ger and J Boudaden and F Wolf and M D\"{o}blinger and T Bein},

url = {https://dx.doi.org/10.1088/2053-1591/acf7ae},

doi = {10.1088/2053-1591/acf7ae},

issn = {2053-1591},

journal = {Materials Research Express},

volume = {10},

number = {9},

pages = {095903},

abstract = {To realize profitable applications with 2D-materials the transition from research scale to microelectronic fabrication methods is needed. This means the use of equipment for larger substrates and assessment of the process flows. In this study we demonstrate an effective way to assess MoS2 as semiconducting material, deposited with the lower priced precursors Mo(CO)6 and H2S on 200 mm silicon wafers. We could show how the evolution of layer quality develops depending on temperature and interface pretreatment. It is not possible to achieve mono-layers of 0.6 nm with high quality due to seeding kinetics and mechanism. In contrast, layers with thicknesses above 3 nm have suitable electrical and optical qualities to proceed with the design of active devices on 200 mm wafers.},

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

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Negative Nonlinear CD\textendashee Dependence in Polycrystalline BINOL Thin Films},

author = {K Liang and F Ristow and K Li and J Pittrich and N Fehn and L D\"{o}rringer and U Heiz and R Kienberger and G Pescitelli and H Iglev and A Kartouzian},

url = {https://doi.org/10.1021/jacs.3c12253},

doi = {10.1021/jacs.3c12253},

issn = {0002-7863},

journal = {Journal of the American Chemical Society},

abstract = {Generally, the relationship between the observed circular dichroism and the enantiomeric excess in chiral systems (CD\textendashee dependence) is linear. While positive nonlinear behavior has often been reported in the past, examples of negative nonlinear (NN) behavior in CD\textendashee dependence are rare and not well understood. Here, we present a strong NN CD\textendashee dependence within polycrystalline thin films of BINOL by using second-harmonic-generation circular dichroism (SHG-CD) and commercial CD spectroscopy studies. Theoretical calculations, microscopy, and FTIR studies are employed to further clarify the underlying cause of this observation. This behavior is attributed to the changing supramolecular chirality of the system. Systems exhibiting NN CD\textendashee dependence hold promise for highly accurate enantiomeric excess characterization, which is essential for the refinement of enantio-separating and -purifying processes in pharmaceuticals, asymmetric catalysis, and chiral sensing. Our findings suggest that a whole class of single-species systems, i.e., racemate crystals, might possess NN CD\textendashee dependence and thus provide us a vast playground to better understand and exploit this phenomenon.},

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

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Transformation-Optics-Designed Plasmonic Singularities for Efficient Photocatalytic Hydrogen Evolution at Metal/Semiconductor Interfaces},

author = {T Lin and T Yang and Y Cai and J Li and G Lu and S Chen and Y Li and L Guo and S A Maier and C Liu and J Huang},

url = {https://doi.org/10.1021/acs.nanolett.3c01287},

doi = {10.1021/acs.nanolett.3c01287},

issn = {1530-6984},

journal = {Nano Letters},

volume = {23},

number = {11},

pages = {5288-5296},

abstract = {Inspired by transformation optics, we propose a new concept for plasmonic photocatalysis by creating a novel hybrid nanostructure with a plasmonic singularity. Our geometry enables broad and strong spectral light harvesting at the active site of a nearby semiconductor where the chemical reaction occurs. A proof-of-concept nanostructure comprising Cu2ZnSnS4 (CZTS) and Au\textendashAu dimer (t-CZTS@Au\textendashAu) is fabricated via a colloidal strategy combining templating and seeded growth. On the basis of numerical and experimental results of different related hybrid nanostructures, we show that both the sharpness of the singular feature and the relative position to the reactive site play a pivotal role in optimizing photocatalytic activity. Compared with bare CZTS, the hybrid nanostructure (t-CZTS@Au\textendashAu) exhibits an enhancement of the photocatalytic hydrogen evolution rate by up to ∼9 times. The insights gained from this work might be beneficial for designing efficient composite plasmonic photocatalysts for diverse photocatalytic reactions.},

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

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Structure\textendashActivity Relationships in Ni- Carboxylate-Type Metal\textendashOrganic Frameworks’ Metamorphosis for the Oxygen Evolution Reaction},

author = {X Ma and D J Zheng and S Hou and S Mukherjee and R Khare and G Gao and Q Ai and B Garlyyev and W Li and M Koch and J Mink and Y Shao-Horn and J Warnan and A S Bandarenka and R A Fischer},

url = {https://doi.org/10.1021/acscatal.3c00625},

doi = {10.1021/acscatal.3c00625},

journal = {ACS Catalysis},

volume = {13},

number = {11},

pages = {7587-7596},

abstract = {Metal\textendashorganic frameworks (MOFs) have been reported to catalyze the oxygen evolution reaction (OER). Despite the established links between the pristine MOFs and their derived metal hydroxide electrocatalysts, several limitations still preclude understanding of the critical factors determining the OER performance. Of prime importance appears the choice of MOF and how its compositions relate to the catalyst stability and in turn to the reconstruction or metamorphosis mechanisms into the active species under OER conditions. An isoreticular series of Ni-carboxylate-type MOFs [Ni2(OH)2L] was chosen to elucidate the effects of the carboxylate linker length expansion and modulation of the linker\textendashlinker π\textendashπ interactions (L = 1,4-benzodicarboxylate, 2,6-napthalenedicarboxylate, biphenyl-4,4′-dicarboxylate, and p-terphenyl-4,4″-dicarboxylate). Degradation and reconstruction of MOFs were systematically investigated. The linker controls the transformation of Ni-MOF into distinct nickel hydroxide phases, and the conversion from α-Ni(OH)2 to β-Ni(OH)2, thus correlating the Ni-MOF composition with the OER activity of the Ni-MOF-derived metastable nickel hydroxide phase mixture.},

keywords = {Foundry Organic, Molecularly-Functionalized},

pubstate = {published},

tppubtype = {article}

}