A5031559723- Perovskite Materials and Applications
- Solid-state spectroscopy and crystallography
- Chalcogenide Semiconductor Thin Films
- Quantum Dots Synthesis And Properties
- Thermal Expansion and Ionic Conductivity
- Optical properties and cooling technologies in crystalline materials
- Luminescence Properties of Advanced Materials
- Conducting polymers and applications
- Nonlinear Optical Materials Research
- Diamond and Carbon-based Materials Research
- High-pressure geophysics and materials
- Nuclear Physics and Applications
- X-ray Diffraction in Crystallography
- Force Microscopy Techniques and Applications
- Molecular Spectroscopy and Structure
- Crystallization and Solubility Studies
- Crystal Structures and Properties
Helmholtz-Zentrum Berlin für Materialien und Energie
2017-2023
University of Potsdam
2019-2020
TU Dortmund University
2019
By using synchrotron X-ray powder diffraction, the temperature dependent phase diagram of hybrid perovskite tri-halide compounds, methyl ammonium lead iodide (MAPbI3, MA+ = CH3NH3+) and bromide (MAPbBr3), as well their solid solutions, has been established. The existence a large miscibility gap between 0.29 ≤ x 0.92 (±0.02) for MAPb(I1-x Br )3 solution proven. A systematic study lattice parameters series at room revealed distinct deviations from Vegard's law. Furthermore, measurements showed...
Abstract Excellent conversion efficiencies of over 20 % and facile cell production have placed hybrid perovskites at the forefront novel solar materials, with CH 3 NH PbI being an archetypal compound. The question why has such extraordinary characteristics, particularly a very efficient power from absorbed light to electrical power, is hotly debated, ferroelectricity promising candidate. This does, however, require crystal structure be non‐centrosymmetric we herein present crystallographic...
This paper discusses the full structural solution of hybrid perovskite formamidinium lead tribromide (FAPbBr 3 ) and its temperature-dependent phase transitions in range from K to 300 using neutron powder diffraction synchrotron X-ray diffraction. Special emphasis is put on influence deuteration formamidinium, position unit cell disordering comparison fully hydrogenated FAPbBr . The measurements show that critically influences crystal structures, i.e. results partially-ordered modifications...
Abstract The halide perovskite CsPbBr 3 belongs to the Cs‐Pb‐Br material system, which features two additional thermodynamically stable ternary phases, Cs 4 PbBr 6 and CsPb 2 Br 5 . coexistence of these phases their reportedly similar photoluminescence (PL) have resulted in a debate on nature emission systems. Herein, optical microscopic characterizations are combined with an effective mass, correlated electron–hole model excitons confined systems, investigate properties system. It is found...
The hybrid halide perovskites MAPbI$_{3}$, MAPbI$_{2.94}$Cl$_{0.06}$, and MAPbCl$_{3}$ (MA - methylammonium) have been investigated using inelastic quasielastic neutron scattering (QENS) with the aim of elucidating impact chloride substitution on rotational dynamics MA. In this context, we discuss influence caused by low-energy phonons QENS resulting from MA in MAPbI$_{3-x}$Cl$_{x}$. Through a comparative temperature-dependent investigation different energy resolutions, which allow wide...
Applications of nitrogen-vacancy (NV) centers in diamond quantum technology have attracted considerable attention recent years. Deterministic generation ensembles NV can advance the research on sensing, many-body systems, multipartite entanglement, and so on. Here we report complete process controlled as well their characterization: growing films through chemical vapor deposition (CVD), ion implantation, spectroscopic characterization defect using a confocal microscope. A microwave-assisted...
In recent years, inorganic cesium–lead–halide perovskites, CsPbX3 (X = I, Br, Cl), have attracted interest for optoelectronic applications such as highly efficient thin-film light-emitting diodes or wide-gap absorber materials photovoltaics. However, phase segregation and secondary phases in as-deposited thin films are still considered to be limiting factors devices based on CsPbX3. Here, we report a correlative electron microscopy spectroscopy approach the identification of their...
Organic or inorganic (A) metal (M) halide (X) perovskites (AMX <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> ) are semiconductor materials setting the basis for development of highly efficient, low-cost and multijunction solar energy conversion devices. The best efficiencies nowadays obtained with mixed compositions containing methylammonium, formamidinium, Cs Rb as well iodine, bromine chlorine anions. understanding fundamental...
Abstract Ihre außergewöhnlich hohen Konversionseffizienzen von über 20 % und die einfache Zellherstellung machen Hybridperowskite zu heißen Kandidaten für alternative Solarzellenmaterialien. CH 3 NH PbI als Archetyp dieser Materialklasse besitzt außergewöhnliche Eigenschaften wie eine sehr effiziente Umwandlung Solarenergie, wobei besonders Ferroelektrizität mögliche Erklärung in den Fokus gerückt ist. Diese erfordert allerdings nicht‐zentrosymmetrische Kristallstruktur notwendige...
The FALCON Laue diffractometer at the Berlin neutron source BERII was developed in collaboration with ILL, Grenoble.It is designed for fast scattering data acquisition of single crystals and makes use a white ("pink") beam wavelength band 0.8-3.2Å as derived from TOF data.Pattern performed by means backscattering transmission detector consisting four iCDD cameras each (Photonic Science).The detectors cover read activ area 400x400 mm2 can be moved to optimize sample-detector...
The halide perovskite CsPbBr$_3$ belongs to the Cs-Pb-Br material system, which features two additional thermodynamically stable ternary phases, Cs$_4$PbBr$_6$ and CsPb$_2$Br$_5$. coexistence of these phases their reportedly similar photoluminescence have resulted in a debate on nature emission systems. Here, we combine optical microscopic characterization with an effective mass, correlated electron-hole model excitons confined systems, investigate properties system. We find that all exhibit...
Inorganic cesium lead halide compounds have gained an increasing interest in the perovskite photovoltaics research community. These are mixed into state of art organic solar cells to provide for more thermal stability, and CsPbX <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> (x=I, Br, Cl) nanocubes investigated as standalone emitter material light emitting diodes. Eventually, reproducible, single-phase CsPbBr thin films couldalso us...
Organic or inorganic (A) metal (M) halide (X) perovskites (AMX3) are semiconductor materials setting the basis for development of highly efficient, low-cost and multijunction solar energy conversion devices. The best efficiencies nowadays obtained with mixed compositions containing methylammonium, formamidinium, Cs Rb as well iodine, bromine chlorine anions. understanding fundamental properties such crystal structure its effect on band gap, their phase stability is essential. In this...
Research interest has increasingly focused on hybrid perovskites MABX 3 like [CH NH ] + (MA), B = Pb and X I or Cl as a future photovoltaic material.In QENS studies it could be shown that chlorine substitution large influence the rotational dynamics of MA molecule in MAPbI 3-x x perovskites.The results show low temperature orthorhombic phase leads to weakening hydrogen bridge bonds (these connect molecules with [PbX 6 -octahedra host structure) since characteristic relaxation times C...
Excellent conversion efficiencies of over 20 % and facile cell production have placed hybrid perovskites at the forefront novel solar materials with CH3NH3PbI3 being its archetypal compound. The question why has such extraordinary characteristics, particularly a hugely efficient light absorption, is hotly debated ferroelectricity promising candidate. This does, however, afford crystal structure to be non-centrosymmetric we herein present crystallographic evidence as how symmetry breaking...