UCLA

In contrast with conventional inorganic semiconductors such as silicon, defects in ionic metal halide perovskite materials are charged. The migration and redistribution of charged defects under a potential gradient (e.g. electrical bias) are known to underly a myriad of detrimental performance- and stability-limiting phenomena in perovskite-based optoelectronic devices. Crucially, the long-term instability issues remain the major bottleneck towards practical usage and commercialization of perovskite-based optoelectronics. Simultaneously, progress in compositional and crystal growth engineering have made possible the controlled fabrication of perovskite thin films with minimized bulk trap density, and it is becoming apparent that defects are predominantly located at the surface and interfaces.