A5063450864- Perovskite Materials and Applications
- Quantum Dots Synthesis And Properties
- Luminescence Properties of Advanced Materials
- Optical properties and cooling technologies in crystalline materials
- Chalcogenide Semiconductor Thin Films
- Solid-state spectroscopy and crystallography
- Conducting polymers and applications
- Photorefractive and Nonlinear Optics
- Organic Electronics and Photovoltaics
- Solid State Laser Technologies
- Glass properties and applications
- Catalysis and Oxidation Reactions
- Magnetic and transport properties of perovskites and related materials
- Gas Sensing Nanomaterials and Sensors
- Electronic and Structural Properties of Oxides
- Organic Light-Emitting Diodes Research
- Radiation Detection and Scintillator Technologies
- ZnO doping and properties
- Advancements in Solid Oxide Fuel Cells
- Advanced Sensor and Energy Harvesting Materials
- Advanced Photocatalysis Techniques
- 2D Materials and Applications
- Spectroscopy and Quantum Chemical Studies
- Food Chemistry and Fat Analysis
- Zeolite Catalysis and Synthesis
Friedrich-Alexander-Universität Erlangen-Nürnberg
2015-2023
Siemens Healthcare (Germany)
2020
Siemens Healthcare (United States)
2019
Centre for Materials for Electronics Technology
2016-2018
S&N (Germany)
2016
Bavarian Center for Applied Energy Research
2016
A major bottleneck delaying the further commercialization of thin-film solar cells based on hybrid organohalide lead perovskites is interface loss in state-of-the-art devices. We present a generic architecture that combines solution-processed, reliable, and cost-efficient hole-transporting materials without compromising efficiency, stability, or scalability perovskite cells. Tantalum-doped tungsten oxide (Ta-WO x )/conjugated polymer multilayers offer surprisingly small barrier form...
In the past few years, hybrid organic–inorganic and all-inorganic metal halide perovskite nanocrystals have become one of most interesting materials for optoelectronic applications. Here, we report a facile rapid room temperature synthesis 15–25 nm formamidinium CH(NH2)2PbX3 (X = Cl, Br, I, or mixed Cl/Br Br/I) colloidal by ligand-assisted reprecipitation (LARP). The cubic platelet-like with their emission in range 415–740 nm, full width at half-maximum (fwhm) 20–44 radiative lifetimes 5–166...
As they combine decent mobilities with extremely long carrier lifetimes, organic-inorganic perovskites have opened a whole new field in opto\-electronics. Measurements of their underlying electronic structure, however, are still lacking. Using angle-resolved photoelectron spectroscopy, we measure the valence band dispersion single-crystal CH$_3$NH$_3$PbBr$_3$. The highest energy is extracted applying modified leading edge method, which accounts for particular density states perovskites....
Abstract Organic solar cells that are free of burn‐in, the commonly observed rapid performance loss under light, presented. The based on poly(3‐hexylthiophene) (P3HT) with varying molecular weights and a nonfullerene acceptor (rhodanine‐benzothiadiazole‐coupled indacenodithiophene, IDTBR) fabricated in air. P3HT:IDTBR light‐soaked over course 2000 h lose about 5% power conversion efficiency (PCE), stark contrast to [6,6]‐Phenyl C61 butyric acid methyl ester (PCBM)‐based whose PCE shows...
Photoinduced degradation mechanisms of CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub> thin films under vacuum and in air are reported.
Long carrier lifetimes and diffusion lengths form the basis for successful application of organic-inorganic perovskite (CH$_3$NH$_3$)PbI$_3$ in solar cells lasers. The mechanism behind long is still not completely understood. Spin-split bands a resulting indirect band gap have been proposed by theory. Using near band-gap left-handed right-handed circularly polarized light we induce photocurrents opposite directions single-crystal device at low temperature ($4~\mathrm{K}$). phenomenom known...
Here we demonstrate a maximum AVT of 46% with an efficiency 3.6%, which is the highest combination and transparency for full device stack to date.
Quantum size-confined CH3NH3PbX3 (X = Br and I) perovskite nanoplatelets with remarkably high photoluminescence quantum yield (up to 90%) were synthesized by ligand-assisted re-precipitation. Thickness-tunability was realized varying the oleylamine oleic acid ligand ratio. This method allows tailoring nanoplatelet thickness adjusting number of unit cell monolayers. Broadly tunable emission wavelengths (450-730 nm) are achieved via pronounced size effect without anion-halide mixing.
While perovskite-based semitransparent solar cells for window applications show competitive levels of transparency and efficiency compared to organic photovoltaics, the color perception perovskite films is highly restricted because band gap engineering results in losses power conversion efficiencies. To overcome limitation visual aesthetics, we combined with dielectric mirrors. This approach enables one tailor device appearance almost any desired simultaneously offers additional light...
Abstract Currently, lead‐based perovskites with mixed multiple cations and hybrid halides are attracting intense research interests due to their promising stability high efficiency. A tremendous amount of 3D 2D perovskite compositions configurations causing a strong demand for throughput synthesis characterization. Furthermore, wide bandgap (≈1.75 eV) as top‐cell materials perovskite–silicon tandem require the screening different overcome photoinduced halide segregation still yielding...
Abstract Here the fabrication of an inorganic metal‐halide perovskite CsPbBr 3 based X‐ray detector is reported utilizing a simple, scalable, and cost‐sensitive melt processing directly on substrate any size. diffraction analysis several 100 mm thick processed films confirms crystalline domains in cm 2 range. The film features resistance 8.5 GΩ hole mobility 18 V −1 s . An to current conversion rate 1450 µC Gy air −2 at electric field 1.2 × 10 4 detection limit sub µ regime demonstrated....
Effective engineering of surface ligands in semiconductor nanocrystals can facilitate the electronic interaction between individual nanocrystals, making them promising for low‐cost optoelectronic applications. Here, use high purity Cu 2 ZnSnS 4 (CZTS) as photoactive layer and hole‐transporting material is reported low‐temperature solution‐processed solar cells. The CZTS are prepared by capped originally with long‐chain organic ligand oleylamine. After removal, show substantial improvement...
We present colloidally stable and highly luminescent Zn<sub>x</sub>Cd<sub>1–x</sub>S:Mn/ZnS core–shell nanocrystals (NCs) as cost-effective light converters for silicon photovoltaic (PV).
Solution-processed oxo-functionalized graphene is used to substitute hydrophilic PEDOT:PSS as an anode interfacial layer for perovskite solar cells. The resulting devices exhibit a reasonable PCE of 15.2% and improved stability.
Metal halide perovskite semiconductors have the potential to enable low-cost, flexible, and efficient solar cells for a wide range of applications. Physical vapor deposition by co-evaporation precursors is method that results in very smooth pinhole-free thin films allows excellent control over film thickness composition. However, become industrially scalable, reproducible process high device yields are essential. Unfortunately, date, reproducibility evaporating organic such as methylammonium...
We measure temperature-dependent one-photon and two-photon induced photoluminescence from (${\mathrm{CH}}_{3}{\mathrm{NH}}_{3}$)${\mathrm{PbBr}}_{3}$ single crystals cleaved in ultrahigh vacuum. An approach is presented to extract absorption spectra a comparison of both measurements. Cleaved exhibit broad spectra. identify the direct optical band gap 2.31 eV. Below 200 K, increases with temperature, it decreases at elevated as described by Bose-Einstein model. excitonic transition found 22...
Solution‐based perovskite solar cell fabrication typically involves rather complex processing sequences to yield highest performance. While most studies concentrate on the exploration of conditions, purity levels common precursor solutions have been investigated and a number impurities that are critically important toward controlling crystallization perovskites found. In this study, an in‐depth chemical study possible formed during CH 3 NH I preparation is presented their relevance revealed....
The hot injection technique for the synthesis of quantum dots (QDs) is a well-established and widely used method in lab. However, scale-up rules do not exist. One reason that particular role process parameters like mixing on particle formation largely unknown, as systematic examination latter impossible laborious complex manual synthesis. Herein we studied induced self-focusing size distributions (PSDs) CdSe QDs using automation combination with defined stirrer geometry. Basis our study...
CsPbBr3 single crystals have potential for application in ionizing-radiation detection devices due to their optimal optoelectronic properties. Yet, mixed ionic-electronic conductivity produces instability and hysteretic artifacts hindering the long-term device operation. Herein, we report an electrical characterization of operating up time scale hours. Our fast time-of-flight measurements reveal bulk mobilities 13-26 cm2 V-1 s-1 with a negative voltage bias dependency. By means guard ring...
Lead halide perovskite nanocrystals (NCs) are the most promising candidates for displays satisfying Rec. 2020 UHDTV color standard. However, moisture sensitivity currently limits light-emitting applications requiring stability and purity. In this study, we propose a large-area FAPbBr3-based quantum dot brightness enhancing film (QDEF) strategy developed in our group five years ago. The combination of polymeric binder tailored to ligands optimized NCs light conversion demonstrates QDEF with...
Despite the intense research on photovoltaic lead halide perovskites, reported optical properties as basic absorption onset and band gap vary significantly. To unambiguously answer question whether discrepancies are a result of differences between bulk "near-surface" material, we perform two nonlinear spectroscopies with drastically different information depths single crystals prototypical (CH3NH3)PbI3 methylammonium iodide. Two-photon absorption, detected via resulting generation carriers...