Intriguing formation pathways of metal halide perovskites and their impact

Metal halide perovskites-based optoelectronic devices have shown remarkable progress in the last several years. However, despite their success in the device performances, there remain many open questions about their fundamental properties. Single crystals are often seen as the model for understanding the fundamental properties and assessing the limits and possibilities of these materials. In addition to delivering high-quality crystals, the nature of the crystallization is closely related to the crystallization of perovskites in thin films, and proper understanding of the mechanism enables a critically needed advance in the reproducibility and quality of both thin films and single crystals for optoelectronic devices. 

In this seminar, I will unveil the reasons behind the observed rapid crystallization in metal halide perovskites. I will show the applications of the newly found information towards the preparation of high-quality thin films, single crystals, and solar cells. To consolidate the electronic properties of these hybrid materials, I will present a comparative study on single crystals and polycrystalline thin films. I will then discuss the impact of heterovalent doping in halide perovskites which is contrary to earlier conclusions. These findings are of central importance to enabling the continued advancement of perovskite optoelectronics and to the improved reproducibility, homogeneity and eventual manufacturability of these technologies. In passing, I will discuss the role of interfacial chemistry in the development of semi-transparent and flexible perovskite-based solar cells.