Pressure-induced dynamics and disorder in the CH3NH3PbBr3 hybrid perovskite

Lead halide perovskite (LHP) semiconductors have garnered much research interest due to their unusual and remarkable properties as optoelectronic materials. The device-relevant high-temperature phase has been measured with X-ray diffraction to be cubic, however there is significant dynamic structural disorder which governs the optoelectronic properties. Despite the ever-increasing understanding of the physics underlying LHP performance, several issues must be addressed before widespread deployment of LHP-based devices is possible. One issue is halide migration, which causes material loss and the buildup of space-charge potentials at interfaces. Halide migration can be reduced with the application of external pressure, suggesting that disorder and migration are linked. In this study we characterize the static and dynamic disorder at high pressures in the prototypical LHP, CH3NH3PbBr3, with a combination of X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS).

Pressure