Related papers: Broadband critical dynamics in disordered lead-bas…
In the prevalent picture of ultrafast structural phase transitions, the atomic motion occurs in a slowly varying potential energy surface determined adiabatically by the fast electrons. However, this ignores non-conservative forces caused…
Point defect tolerance in materials, which extends operational lifetime, is essential for societal sustainability, and the creation of a framework to design such properties is a grand challenge in the material sciences. Using three…
Halide perovskites make efficient solar cells due to their exceptional optoelectronic properties, but suffer from several stability issues. The characterization of the degradation processes is challenging because of the limitations in the…
The ability to control the structure of a crystalline solid on ultrafast timescales bears enormous potential for information storage and manipulation or generating new functional states of matter [1]. In many materials where the ultrafast…
State-of-the-art hybrid perovskites have demonstrated excellent functionality in photovoltaics and light-emitting applications, and have emerged as a promising candidate for exciton-polariton (polariton) optoelectronics. In the strong…
Relaxor ferrolectrics are important in technological applications due to a strong electromechanical response, energy storage capacity, electrocaloric effect, and pyroelectric energy conversion properties. Current efforts to discover and…
The low-energy part of vibration spectrum in PbMg$_{1/3}$Nb$_{2/3}$O$_3$ relaxor ferroelectric was studied by inelastic neutron scattering. We observed the coexistence of a resolution-limited central peak with strong quasielastic…
Pb-based perovskites with multiple cations are fascinating materials showing various phenomena such as high piezoelectric, electromechanical, and relaxor properties. While chemical disordering accompanied by polar nanoregions and nanosized…
Ruddlesden-Popper hybrid halide perovskite are quasi-two-dimensional materials with a layered structure and structural dynamics that are determined by the interplay between the organic and inorganic layers. While their optical properties…
Structural phase transitions in the organic inorganic metal halide perovskites are driven via rearrangement of methylammonium cation and distortion in the PbX6 octahedra. Compositional tuning is usually incorporated for suppression of the…
Organic-inorganic halide perovskites have been intensively re-investigated due to their applications, yet the opto-electronic function of the organic cation remains unclear. Through organic-selective resonant Auger electron spectroscopy…
Recent advances of highly efficient solar cells based on organic-inorganic halide perovskites have triggered intense research efforts to establish the fundamental properties of these materials. In this work, we utilized diamond anvil cell…
We identify the existence of nonlinear optical (NLO) activity in a number of novel $ABX_3$-type metal-free perovskites, where $A$ is a highly tuneable organic cation, $B$ is a NH$_4$ cation and $X$ a halide anion. Through systematic…
Anharmonicity and local disorder (polymorphism) are ubiquitous in perovskite physics, inducing various phenomena observed in scattering and spectroscopy experiments. Several of these phenomena still lack interpretation from first-principles…
Doping organic metal-halide perovskites with cesium could be the best solution to stabilize highly-efficient perovskite solar cells. The understanding of the respective roles of the organic molecule, on one hand, and the inorganic lattice,…
The development of next generation perovskite-based optoelectronic devices relies critically on the understanding of the interaction between charge carriers and the polar lattice in out-of-equilibrium conditions. While it has become…
Lead-free metal halide perovskites are emerging as less-toxic alternatives to their lead-based counterparts. However, their applicability in optoelectronic devices is limited, and the charge transport dynamics remain poorly understood.…
Hot carrier solar cells hold promise for exceeding the Shockley-Queisser limit. Slow hot carrier cooling is one of the most intriguing properties of lead halide perovskites and distinguishes this class of materials from competing materials…
Halide perovskite semiconductors respond to electric fields in a way that varies across time and length scales. We discuss the microscopic processes that give rise to the macroscopic polarization of these materials, ranging from the optical…
Metal halide perovskites make up a promising class of materials for semiconductor spintronics. Here we report a systematic investigation of coherent spin precession, spin dephasing and spin relaxation of electrons and holes in two hybrid…