Abstract

Colloidal metal halide nanocrystals took materials science by storm since their emergence several years ago. Exemplified by cesium lead halide perovskites, such materials show bright and tunable photoluminescence and are cheap and deceptively simple to make. On the one hand, these characteristics spurred applications of colloidal perovskites as low-cost phosphors in LEDs, color converters, and light absorbers in thin-film solar cells. On the other hand, intense attention has uncovered phenomena unique to or remarkably pronounced only in colloidal metal halides. In this talk, I will discuss my pursuit of two such phenomena: the search for cooperative light emission (superfluorescence) and the discovery of structural coherence in metal halide nanocrystal superlattices.