Related papers: Anisotropic Defect Diffusion in Layered CsPbBr$_\m…
Strong deviations in the finite temperature atomic structure of halide perovskites from their average geometry can have profound impacts on optoelectronic and other device-relevant properties. Detailed mechanistic understandings of these…
The post-perovskite phase of (Mg,Fe)SiO3 is believed to be the main mineral phase of the Earth's lowermost mantle (the D" layer). Its properties explain numerous geophysical observations associated with this layer - for example, the D''…
The oxygen-exchange behavior has been studied in half-doped manganese and cobalt perovskite oxides. We have found that the oxygen diffusivity in Gd_{0.5}Ba_{0.5}MnO_{3-\delta} can be enhanced by orders of magnitude by inducing…
Halide perovskites exhibit significant advantages for active optical components such as light emitting diodes, solar cells and photodetectors due to their excellent optoelectronic properties. Their nonlinear optical effects and other…
Organic-inorganic halide perovskite solar cells have recently attracted much attention due to their low-cost fabrication, flexibility, and high-power conversion efficiency. The reduction from three- to two-dimension (2D) promises an…
Phase segregation is a critical phenomenon that influences the stability and performance of mixed halide perovskite based opto-electronic devices. In addition to the underlying physical mechanisms, the spatial pattern and randomness…
The long-term stability of halide perovskite solar cells (PSCs) remains the critical problem of this photovoltaic technology. Different structural defects formed in the thin-film perovskite films were considered as a main trigger for the…
Using first principles density functional theory calculations, we show how Rashba-type energy band splitting in the hybrid organic-inorganic halide perovskites APbX$_3$ (A=CH$_3$NH$_3^+$, CH(NH$_2$)$_2^+$, Cs$^+$ and X=I, Br) can be tuned…
Investigation of the inherent field-driven charge transport behaviour of 3D lead halide perovskites has largely remained a challenging task, owing primarily to undesirable ionic migration effects near room temperature. In addition, the…
Solar cells based on hybrid perovskites have shown high efficiency while possessing simple processing methods. To gain a fundamental understanding of their properties on an atomic level, we investigate single crystals of CH3NH3PbI3 with a…
Halide perovskites have emerged as promising photonic materials for fundamental physics studies and technological applications. Their potential for nonlinear optics has also drawn great interest recently; yet, to date, continuous-wave (CW)…
We show that the decomposition of caesium lead halide perovskite nanocrystals under continuous X-ray illumination depends on the surface ligand. For oleic acid/oleylamine, we observe a fast decay accompanied by the formation of elemental…
The unprecedented structural flexibility and diversity of inorganic frameworks of layered hybrid halide perovskites (LHHPs) rise up a wide range of useful optoelectronic properties thus predetermining the extraordinary high interest to this…
Mixed-halide lead perovskites, with photoexcited charge-carrier properties suitable for high-efficiency photovoltaics, hold significant promise for high-efficiency tandem solar cells. However, phase segregation under illumination, where an…
The local crystal structures of many perovskite-structured materials deviate from the average space group symmetry. We demonstrate, from lattice-dynamics calculations based on quantum chemical force constants, that all the caesium-lead and…
Coherent misfitting precipitates in elastically stressed media such as $\gamma \prime$ particles in nickel-based super-alloys show various splitting patterns such as doublets, quartets, or octets due to their misfit strain energy. While it…
Organic-inorganic hybrid halide perovskites have ignited tremendous interests for photovoltaic applications. However, their nonlinear optical response has not been studied although many of these structures lack the centrosymmetry and…
Organic or inorganic (A) metal (M) halide (X) perovskites (AMX3) are semiconductor materials setting the basis for the development of highly efficient, low-cost and multijunction solar energy conversion devices. The best efficiencies…
Hybrid lead-halide perovskites have emerged as an excellent class of photovoltaic materials. Recent reports suggest that the organic molecular cation is responsible for local polar fluctuations that inhibit carrier recombination. We combine…
A uniaxial strain applied to graphene-like materials moves the Dirac nodes along the boundary of the Brillouin zone. An extreme case is the merging of the Dirac node positions to a single degenerate spectral node which gives rise to a new…