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@article{nokey,

title = {Optimizing Carrier Balance in CsPbBr3 Nanocrystal LEDs: The Role of Alkyl Ligands and Polar Electron Transport Layers},

author = {R Jayabalan and G K Hanumantharaju and T Hettiger and A Sarkar and F S Zu and A Ullrich and A Abfalterer and A S Urban and N Koch and D Andrienko and M Scheele and W Br\"{u}tting},

url = {\<Go to ISI\>://WOS:001556372500001},

doi = {10.1002/adom.202501361},

issn = {2195-1071},

year  = {2025},

date = {2025-08-26},

journal = {Advanced Optical Materials},

abstract = {The study of lead halide perovskite nanocrystal based light-emitting diodes (LEDs) has advanced significantly, with notable improvements in stability and optical properties. However, optimizing charge carrier injection and transport remains a challenge. Efficient electroluminescence requires a balanced transport of both holes and electrons within the emitting material. Here, cubic CsPbBr3 nanocrystals passivated with oleylamine and oleic acid are investigated, comparing them to ligand-exchanged nanocrystals with didodecyldimethylammonium bromide (DDABr). Nuclear magnetic resonance spectroscopy and transmission electron microscopy confirm successful ligand exchange, revealing reduced ligand coverage in DDABr-treated nanocrystals. Photoelectron spectroscopy, spectroelectrochemistry, and single-carrier devices indicate improved hole injection in DDABr-capped nanocrystals. Density functional theory calculations further reveal the influence of ligand type and coverage on energy levels, with oleic acid introducing localized states in native nanocrystals. Additionally, incorporation of a polar electron transport layer enhances LED performance by over an order of magnitude in DDABr-capped nanocrystals, driven by improved charge balance arising from the spontaneous orientation polarization of the electron transport layer. These findings highlight the critical role of ligand selection, passivation degree, and charge transport control by the adjacent organic transport layers in optimizing LED efficiency.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Design Rules for Perovskite Nanocrystals: Volume-Governed Absorption Versus Shape-Controlled Auger Recombination},

author = {A Singldinger and P Haussmann and G Debuisschert and N A Henke and J Paul and L Luber and P Ganswindt and A Abfalterer and A S Urban},

url = {\<Go to ISI\>://WOS:001523269600001},

doi = {10.1002/adom.202501137},

issn = {2195-1071},

year  = {2025},

date = {2025-07-07},

journal = {Advanced Optical Materials},

abstract = {Understanding the interplay between morphology and optical properties in lead halide perovskite nanocrystals is critical for advancing optoelectronic applications. In this study, the one-photon absorption (OPA) cross-section and biexciton Auger lifetimes of CsPbBr3 nanocrystals with varying dimensionality, including nanocubes, nanoplatelets, and nanorods, are investigated. Using ultrafast transient absorption spectroscopy, the OPA cross-section is extracted from fluence-dependent measurements and the decay dynamics of excitonic states are examined. The results reveal that the OPA cross-section scales linearly with nanocrystal volume, irrespective of morphology, providing the most comprehensive experimental validation of this relationship to date. Furthermore, the universal volume scaling law for biexciton Auger recombination is confirmed in the strong confinement regime, but deviations from it in the weak confinement regime are demonstrated. The biexciton Auger lifetime saturates for nanocrystals with dimensions exceeding the exciton Bohr radius, while nanorods and nanoplatelets exhibit shape-dependent confinement effects that influence their carrier recombination dynamics. These findings offer valuable insights into the design of perovskite nanocrystals for high-performance optoelectronic devices, including light-emitting diodes, lasers, and photodetectors.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Locking in Color: Stable RGB Perovskite Nanocrystal Films via UV Cross-Linking},

author = {P Ganswindt and I Tepfenhart and A Singldinger and A Abfalterer and L Spies and E Kostyurina and M Stadler and B Nickel and A S Urban},

url = {https://doi.org/10.1002/adom.202500166},

doi = {https://doi.org/10.1002/adom.202500166},

issn = {2195-1071},

year  = {2025},

date = {2025-04-07},

journal = {Advanced Optical Materials},

volume = {n/a},

number = {n/a},

pages = {2500166},

abstract = {Abstract Perovskite nanocrystals have positioned themselves at the forefront of next-generation emitter applications due to their extraordinary optoelectronic properties, which include widely tunable narrow emission spectra and low-cost syntheses. However, stability issues and halide ion exchange inhibit the realization of heterostructures, severely limiting their applicability and decelerating their commercialization. Here, a block copolymer templated halide perovskite nanocrystal synthesis with a post-synthetic treatment is combined with UV-C light to obtain ultra-stable thin film emitters. The UV light induces cross-linking between the polymer strands, thereby rendering them insoluble to the organic solvent and nearly impervious to halide ion diffusion while retaining the nanocrystals? optical properties. This method enabled the fabrication of an all-perovskite nanocrystal white light-emitting thin film. The resulting films feature narrow linewidths (\<95 meV) for each RGB emission peak. Additionally, the color temperature of the ?white? light can be tuned with a color gamut approximating the Rec. 2020 standard. These RGB-emissive phosphor films can be combined with commercial UV or blue LED backlights to create the next-generation high-efficiency, high-quality phosphor-converted white LEDs or color displays.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Synthesis of Cs3Cu2I5 Nanocrystals in a Continuous Flow System},

author = {K Arslanova and P Ganswindt and T Lorenzen and E Kostyurina and K Karaghiosoff and B Nickel and K M\"{u}ller-Caspary and A S Urban},

url = {https://doi.org/10.1002/smll.202403572},

doi = {https://doi.org/10.1002/smll.202403572},

issn = {1613-6810},

year  = {2024},

date = {2024-11-01},

journal = {Small},

volume = {20},

number = {44},

pages = {2403572},

abstract = {Abstract Achieving the goal of generating all of the world's energy via renewable sources and significantly reducing the energy usage will require the development of novel, abundant, nontoxic energy conversion materials. Here, a cost-efficient and scalable continuous flow synthesis of Cs3Cu2I5 nanocrystals is developed as a basis for the rapid advancement of novel nanomaterials. Ideal precursor solutions are obtained through a novel batch synthesis, whose product served as a benchmark for the subsequent flow synthesis. Realizing this setup enabled a reproducible fabrication of Cs3Cu2I5 nanocrystals. The effect of volumetric flow rate and temperature on the final product's morphology and optical properties are determined, obtaining 21% quantum yield with the optimal configuration. Consequently, the size and morphology of the nanocrystals can be tuned with far more precision and in a much broader range than previously achievable. The flow setup is readily applicable to other relevant nanomaterials. It should enable a rapid determination of a material's potential and subsequently optimize its desired properties for renewable energy generation or efficient optoelectronics.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Antisolvent controls the shape and size of anisotropic lead halide perovskite nanocrystals},

author = {K Frank and N A Henke and C Lampe and T Lorenzen and B M\"{a}rz and X Sun and S Haas and O Gutowski and A-C Dippel and V Mayer and K M\"{u}ller-Caspary and A S Urban and B Nickel},

url = {https://doi.org/10.1038/s41467-024-53221-5},

doi = {10.1038/s41467-024-53221-5},

issn = {2041-1723},

year  = {2024},

date = {2024-10-17},

journal = {Nature Communications},

volume = {15},

number = {1},

pages = {8952},

abstract = {Colloidal lead halide perovskite nanocrystals have potential for lighting applications due to their optical properties. Precise control of the nanocrystal dimensions and composition is a prerequisite for establishing practical applications. However, the rapid nature of their synthesis precludes a detailed understanding of the synthetic pathways, thereby limiting the optimisation. Here, we deduce the formation mechanisms of anisotropic lead halide perovskite nanocrystals, 1D nanorods and 2D nanoplatelets, by combining in situ X-ray scattering and photoluminescence spectroscopy. In both cases, emissive prolate nanoclusters form when the two precursor solutions are mixed. The ensuing antisolvent addition induces the divergent anisotropy: The intermediate nanoclusters are driven into a dense hexagonal mesophase, fusing to form nanorods. Contrastingly, nanoplatelets grow freely dispersed from dissolving nanoclusters, stacking subsequently in lamellar superstructures. Shape and size control of the nanocrystals are determined primarily by the antisolvent’s dipole moment and Hansen hydrogen bonding parameter. Exploiting the interplay of antisolvent and organic ligands could enable more complex nanocrystal geometries in the future.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Fine-Tuning Blue-Emitting Halide Perovskite Nanocrystals},

author = {S Martin and N A Henke and C Lampe and M D\"{o}blinger and K Frank and P Ganswindt and B Nickel and A S Urban},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adom.202301009},

doi = {https://doi.org/10.1002/adom.202301009},

issn = {2195-1071},

year  = {2023},

date = {2023-08-02},

journal = {Advanced Optical Materials},

volume = {n/a},

number = {n/a},

pages = {2301009},

abstract = {Abstract Lead halide perovskite nanocrystals (NCs) with narrow, bright emission in the visible range are promising candidates for light-emitting applications. Near-unity quantum yields have been realized for green and red-emitting perovskites, but efficient, stable blue-emitting perovskite materials are scarce. Current methods to synthesize quantum-confined CsPbBr3 NCs with blue emission are limited to specific wavelength ranges and still suffer from inhomogeneously broadened emission profiles. Herein, anisotropic blue-green emitting CsPbBr3 NCs are synthesized in ambient atmosphere using a spontaneous crystallization method. Optical spectroscopy reveals a gradual, asymptotic photoluminescence (PL) redshift of pristine colloidal NCs after synthesis. During this process, the emission quality improves notably as the PL spectra become narrower and more symmetric, accompanied by a PL intensity increase. Electron microscopy indicates that the gradual redshift stems from an isotropic growth of the CsPbBr3 NCs in at least two dimensions, likely due to residual precursor ions in the dispersion. Most importantly, the growth process can be halted at any point by injecting an enhancement solution containing PbBr2 and organic capping ligands. Thus, excellent control over NC size is achieved, allowing for nanometer-precise tunability of the respective emission wavelength in the range between 475 and 500 nm, enhancing the functionality of these already impressive NCs.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Lead-free, luminescent perovskite nanocrystals obtained through ambient condition synthesis},

author = {F Treber and K Frank and B Nickel and C Lampe and A S Urban},

url = {https://arxiv.org/abs/2301.08936},

doi = {https://doi.org/10.48550/arXiv.2301.08936},

year  = {2023},

date = {2023-01-21},

journal = {arXiv preprint arXiv:2301.08936},

abstract = {Heterovalent substitution of toxic lead is an increasingly popular design strategy to obtain environmentally sustainable variants of the exciting material class of halide perovskites. Perovskite nanocrystals (NCs) obtained through solution-based methods exhibit exceedingly high optical quality. Unfortunately, most of these synthesis routes still require reaction under inert gas and at very high temperatures. Herein we present a novel synthesis routine for lead-free double perovskite NCs. We combine hot injection and ligand-assisted reprecipitation (LARP) methods to achieve a low-temperature and ambient atmosphere-based synthesis for manganese-doped Cs_2NaBiCl_6 NCs. Mn incorporation is critical for the otherwise non-emissive material, with a 9:1 Bi:Mn precursor ratio maximizing the bright orange photoluminescence (PL) and quantum yield (QY). Higher temperatures slightly increased the material's performance, yet NCs synthesized at room temperature were still emissive, highlighting the versatility of the synthetic approach. Furthermore, the NCs show excellent long-term stability in ambient conditions, facilitating additional investigations and energy-related applications.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Rapid Data-Efficient Optimization of Perovskite Nanocrystal Syntheses through Machine Learning Algorithm Fusion},

author = {C Lampe and I Kouroudis and M Harth and S Martin and A Gagliardi and A S Urban},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adma.202208772},

doi = {https://doi.org/10.1002/adma.202208772},

issn = {0935-9648},

year  = {2023},

date = {2023-01-21},

urldate = {2023-01-21},

journal = {Advanced Materials},

volume = {35},

issue = {16},

pages = {2208772},

abstract = {Abstract With the demand for renewable energy and efficient devices rapidly increasing, a need arises to find and optimize novel (nano)materials. With sheer limitless possibilities for material combinations and synthetic procedures, obtaining novel, highly functional materials has been a tedious trial and error process. Recently, machine learning has emerged as a powerful tool to help optimize syntheses; however, most approaches require a substantial amount of input data, limiting their pertinence. Here, we merge three well-known machine-learning models with Bayesian Optimization into one to optimize the synthesis of CsPbBr3 nanoplatelets with limited data demand. The algorithm can accurately predict the photoluminescence emission maxima of nanoplatelet dispersions using only the three precursor ratios as input parameters. This allowed us to fabricate previously unobtainable 7 and 8 monolayer-thick nanoplatelets. Moreover, the algorithm dramatically improved the homogeneity of 2-6 monolayer-thick nanoplatelet dispersions, as evidenced by narrower and more symmetric photoluminescence spectra. Decisively, only 200 total syntheses were required to achieve this vast improvement, highlighting how rapidly material properties can be optimized. The algorithm is highly versatile and can incorporate additional synthetic parameters. Accordingly, it is readily applicable to other less-explored nanocrystal syntheses and can help rapidly identify and improve exciting compositions' quality. This article is protected by copyright. All rights reserved},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {High-Performance Monolayer MoS2 Field-Effect Transistors on Cyclic Olefin Copolymer-Passivated SiO2 Gate Dielectric},

author = {S B Kalkan and E Najafidehaghani and Z Gan and J Drewniok and M F Lichtenegger and U H\"{u}bner and A S Urban and A George and A Turchanin and B Nickel},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adom.202201653},

doi = {https://doi.org/10.1002/adom.202201653},

issn = {2195-1071},

year  = {2022},

date = {2022-11-18},

journal = {Advanced Optical Materials},

volume = {n/a},

number = {n/a},

pages = {2201653},

abstract = {Abstract Trap states of the semiconductor/gate dielectric interface give rise to a pronounced subthreshold behavior in field-effect transistors (FETs) diminishing and masking intrinsic properties of 2D materials. To reduce the well-known detrimental effect of SiO2 surface traps, this work spin-coated an ultrathin (≈5 nm) cyclic olefin copolymer (COC) layer onto the oxide and this hydrophobic layer acts as a surface passivator. The chemical resistance of COC allows to fabricate monolayer MoS2 FETs on SiO2 by standard cleanroom processes. This way, the interface trap density is lowered and stabilized almost fivefold, to around 5 × 1011 cm−2 eV−1, which enables low-voltage FETs even on 300 nm thick SiO2. In addition to this superior electrical performance, the photoresponsivity of the MoS2 devices on passivated oxide is also enhanced by four orders of magnitude compared to nonpassivated MoS2 FETs. Under these conditions, negative photoconductivity and a photoresponsivity of 3 × 107 A W−1 is observed which is a new highest value for MoS2. These findings indicate that the ultrathin COC passivation of the gate dielectric enables to probe exciting properties of the atomically thin 2D semiconductor, rather than interface trap dominated effects.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Machine-Learning-Optimized Perovskite Nanoplatelet Synthesis},

author = {C Lampe and I Kouroudis and M Harth and S Martin and A Gagliardi and A S Urban},

url = {https://arxiv.org/abs/2210.09783},

doi = {https://doi.org/10.48550/arXiv.2210.09783},

year  = {2022},

date = {2022-10-18},

journal = {arXiv preprint arXiv:2210.09783},

abstract = {With the demand for renewable energy and efficient devices rapidly increasing, a need arises to find and optimize novel (nano)materials. This can be an extremely tedious process, often relying significantly on trial and error. Machine learning has emerged recently as a powerful alternative; however, most approaches require a substantial amount of data points, i.e., syntheses. Here, we merge three machine-learning models with Bayesian Optimization and are able to dramatically improve the quality of CsPbBr3 nanoplatelets (NPLs) using only approximately 200 total syntheses. The algorithm can predict the resulting PL emission maxima of the NPL dispersions based on the precursor ratios, which lead to previously unobtainable 7 and 8 ML NPLs. Aided by heuristic knowledge, the algorithm should be easily applicable to other nanocrystal syntheses and significantly help to identify interesting compositions and rapidly improve their quality.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Thickness-Dependent Dark-Bright Exciton Splitting and Phonon Bottleneck in CsPbBr3-Based Nanoplatelets Revealed via Magneto-Optical Spectroscopy},

author = {S Wang and M Dyksik and C Lampe and M Gramlich and D K Maude and M Baranowski and A S Urban and P Plochocka and A Surrente},

url = {https://doi.org/10.1021/acs.nanolett.2c01826},

doi = {10.1021/acs.nanolett.2c01826},

issn = {1530-6984},

year  = {2022},

date = {2022-08-29},

journal = {Nano Letters},

volume = {22},

number = {17},

pages = {7011-7019},

abstract = {The optimized exploitation of perovskite nanocrystals and nanoplatelets as highly efficient light sources requires a detailed understanding of the energy spacing within the exciton manifold. Dark exciton states are particularly relevant because they represent a channel that reduces radiative efficiency. Here, we apply large in-plane magnetic fields to brighten optically inactive states of CsPbBr3-based nanoplatelets for the first time. This approach allows us to access the dark states and directly determine the dark-bright splitting, which reaches 22 meV for the thinnest nanoplatelets. The splitting is significantly less for thicker nanoplatelets due to reduced exciton confinement. Additionally, the form of the magneto-PL spectrum suggests that dark and bright state populations are nonthermalized, which is indicative of a phonon bottleneck in the exciton relaxation process.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Energy Transfer in Stability-Optimized Perovskite Nanocrystals},

author = {M G Greiner and A Singldinger and N A Henke and C Lampe and U Leo and M Gramlich and A S Urban},

url = {https://doi.org/10.1021/acs.nanolett.2c02108},

doi = {10.1021/acs.nanolett.2c02108},

issn = {1530-6984},

year  = {2022},

date = {2022-08-08},

urldate = {2022-08-08},

journal = {Nano Letters},

volume = {22},

issue = {16},

pages = {6709-6715},

abstract = {Outstanding optoelectronic properties and a facile synthesis render halide perovskite nanocrystals (NCs) a promising material for nanostructure-based devices. However, the commercialization is hindered mainly by the lack of NC stability under ambient conditions and inefficient charge carrier injection. Here, we investigate solutions to both problems, employing methylammonium lead bromide (MAPbBr3) NCs encapsulated in diblock copolymer core\textendashshell micelles of tunable size. We confirm that the shell does not prohibit energy transfer, as FRET efficiencies between these NCs and 2D CsPbBr3 nanoplatelets (NPLs) reach 73.6%. This value strongly correlates to the micelle size, with thicker shells displaying significantly reduced FRET efficiencies. Those high efficiencies come with a price, as the thinnest shells protect the encapsulated NCs less from environmentally induced degradation. Finding the sweet spot between efficiency and protection could lead to the realization of tailored energy funnels with enhanced carrier densities for high-power perovskite NC-based optoelectronic applications.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Electron\textendashHole Binding Governs Carrier Transport in Halide Perovskite Nanocrystal Thin Films},

author = {M F Lichtenegger and J Drewniok and A Bornschlegl and C Lampe and A Singldinger and N A Henke and A S Urban},

url = {https://doi.org/10.1021/acsnano.2c00369},

doi = {10.1021/acsnano.2c00369},

issn = {1936-0851},

year  = {2022},

date = {2022-03-18},

journal = {ACS Nano},

abstract = {Two-dimensional halide perovskite nanoplatelets (NPLs) have exceptional light-emitting properties, including wide spectral tunability, ultrafast radiative decays, high quantum yields (QY), and oriented emission. Due to the high binding energies of electron\textendashhole pairs, excitons are generally considered the dominant species responsible for carrier transfer in NPL films. To realize efficient devices, it is imperative to understand how exciton transport progresses therein. We employ spatially and temporally resolved optical microscopy to map exciton diffusion in perovskite nanocrystal (NC) thin films between 15 °C and 55 °C. At room temperature (RT), we find the diffusion length to be inversely correlated to the thickness of the nanocrystals (NCs). With increasing temperatures, exciton diffusion declines for all NC films, but at different rates. This leads to specific temperature turnover points, at which thinner NPLs exhibit higher diffusion lengths. We attribute this anomalous diffusion behavior to the coexistence of excitons and free electron hole-pairs inside the individual NCs within our temperature range. The organic ligand shell surrounding the NCs prevents charge transfer. Accordingly, any time an electron\textendashhole pair spends in the unbound state reduces the FRET-mediated inter-NC transfer rates and, consequently, the overall diffusion. These results clarify how exciton diffusion progresses in strongly confined halide perovskite NC films, emphasizing critical considerations for optoelectronic devices.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {How Exciton\textendashPhonon Coupling Impacts Photoluminescence in Halide Perovskite Nanoplatelets},

author = {M Gramlich and C Lampe and J Drewniok and A S Urban},

url = {https://doi.org/10.1021/acs.jpclett.1c03437},

doi = {10.1021/acs.jpclett.1c03437},

year  = {2021},

date = {2021-11-18},

journal = {The Journal of Physical Chemistry Letters},

pages = {11371-11377},

abstract = {Semiconductor nanocrystals are receiving increased interest as narrow-band emitters for display applications. Here, we investigate the underlying photoluminescence (PL) linewidth broadening mechanisms in thickness-tunable 2D halide perovskite (Csn−1PbnBr3n+1) nanoplatelets (NPLs). Temperature-dependent PL spectroscopy on NPL thin films reveals a blue-shift of the PL maximum for thicker NPLs, no shift for three monolayer (ML) thick NPLs, and a red-shift for the thinnest (2 ML) NPLs with increasing temperature. Emission linewidths also strongly depend on NPL thickness, with the thinnest NPLs showing the smallest temperature-induced broadening. We determine the combined interaction of exciton\textendashphonon coupling and thermal lattice expansion to be responsible for both effects. Additionally, the 2 ML NPLs exhibit a significantly larger Fr\"{o}hlich coupling constant and optical phonon energy, possibly due to an inversion in the exciton fine structure. These results illustrate that ultrathin halide perovskite NPLs could illuminate the next generation of displays, provided a slightly greater sample homogeneity and improved stability.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Dark and Bright Excitons in Halide Perovskite Nanoplatelets},

author = {M Gramlich and M W Swift and C Lampe and M D\"{o}blinger and J L Lyons and A L Efros and P C Sercel and A S Urban},

year  = {2021},

date = {2021-10-01},

journal = {arXiv preprint arXiv},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Thickness-Dependence of Exciton-Exciton Annihilation in Halide Perovskite Nanoplatelets},

author = {M Gramlich and B J Bohn and Y Tong and L Polavarapu and J Feldmann and A S Urban},

url = {\<Go to ISI\>://WOS:000547468400064},

doi = {10.1021/acs.jpclett.0c01291},

issn = {1948-7185},

year  = {2020},

date = {2020-06-14},

journal = {Journal of Physical Chemistry Letters},

volume = {11},

number = {13},

pages = {5361-5366},

abstract = {Exciton-exciton annihilation (EEA) and Auger recombination are detrimental processes occurring in semiconductor optoelectronic devices at high carrier densities. Despite constituting one of the main obstacles for realizing lasing in semiconductor nanocrystals (NCs), the dependencies on NC size are not fully understood, especially for those with both weakly and strongly confined dimensions. Here, we use differential transmission spectroscopy to investigate the dependence of EEA on the physical dimensions of thickness-controlled 2D halide perovskite nanoplatelets (NPIs). We find the EEA lifetimes to be extremely short on the order of 7-60 ps. Moreover, they are strongly determined by the NP1 thickness with a power law dependence according to tau(2) proportional to d(5.3). Additional measurements show that the EEA lifetimes also increase for NPIs with larger lateral dimensions. dimensions is critical for deciphering the fundamental laws governing These results show that a precise control of the physical the process especially in 1D and 2D NCs.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Nonradiative Energy Transfer between Thickness-Controlled Halide Perovskite Nanoplatelets},

author = {A Singldinger and M Gramlich and C Gruber and C Lampe and A S Urban},

url = {\<Go to ISI\>://WOS:000535176100006},

doi = {10.1021/acsenergylett.0c00471},

issn = {2380-8195},

year  = {2020},

date = {2020-05-08},

journal = {Acs Energy Letters},

volume = {5},

number = {5},

pages = {1380-1385},

abstract = {Despite showing great promise for optoelectronics, the commercialization of halide perovskite nanostructure-based devices is hampered by inefficient electrical excitation and strong exciton binding energies. While transport of excitons in an energy-tailored system via Forster resonance energy transfer (FRET) could be an efficient alternative, halide ion migration makes the realization of cascaded structures difficult. Here, we show how these could be obtained by exploiting the pronounced quantum confinement effect in two-dimensional CsPbBr3-based nanoplatelets (NPls). In thin films of NPls of two predetermined thicknesses, we observe an enhanced acceptor photoluminescence (PL) emission and a decreased donor PL lifetime. This indicates a FRET-mediated process, benefitted by the structural parameters of the NPls. We determine corresponding transfer rates up to k(FRET) = 0.99 ns(-1) and efficiencies of nearly eta(FRET) = 70%. We also show FRET to occur between perovskite NPls of other thicknesses. Consequently, this strategy could lead to tailored energy cascade nanostructures for improved optoelectronic devices.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Real-Time Electron and Hole Transport Dynamics in Halide Perovskite Nanowires},

author = {L Janker and Y Tong and L Polavarapu and J Feldmann and A S Urban and H J Krenner},

url = {\<Go to ISI\>://WOS:000502687500044},

doi = {10.1021/acs.nanolett.9b03396},

issn = {1530-6984},

year  = {2019},

date = {2019-10-30},

journal = {Nano Letters},

volume = {19},

number = {12},

pages = {8701-8707},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Polymer Nanoreactors Shield Perovskite Nanocrystals from Degradation},

author = {V A Hintermayr and C Lampe and M Low and J Roemer and W Vanderlinden and M Gramlich and A X Bohm and C Sattler and B Nickel and T Lohmuller and A S Urban},

url = {\<Go to ISI\>://WOS:000481563800015},

doi = {10.1021/acs.nanolett.9b00982},

issn = {1530-6984},

year  = {2019},

date = {2019-07-19},

journal = {Nano Letters},

volume = {19},

number = {8},

pages = {4928-4933},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Identifying and Reducing Interfacial Losses to Enhance Color-Pure Electroluminescence in Blue-Emitting Perovskite Nanoplatelet Light-Emitting Diodes},

author = {R L Z Hoye and M L Lai and M Anaya and Y Tong and K Galkowski and T Doherty and W W Li and T N Huq and S Mackowski and L Polavarapu and J Feldmann and J L Macmanus-Driscoll and R H Friend and A S Urban and S D Stranks},

url = {\<Go to ISI\>://WOS:000468015600025},

doi = {10.1021/acsenergylett.9b00571},

issn = {2380-8195},

year  = {2019},

date = {2019-04-17},

journal = {Acs Energy Letters},

volume = {4},

number = {5},

pages = {1181-1188},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Tuning the optical bandgap in layered hybrid perovskites through variation of alkyl chain length},

author = {J A Sichert and A Hemmerling and C Cardenas-Daw and A S Urban and J Feldmann},

url = {\<Go to ISI\>://WOS:000466615300017},

doi = {10.1063/1.5087296},

issn = {2166-532X},

year  = {2019},

date = {2019-04-16},

journal = {Apl Materials},

volume = {7},

number = {4},

keywords = {},

pubstate = {published},

tppubtype = {article}

}