Modifications to perovskites and other ternary metal halide nanocrystals for optoelectronic applications

Lead-based perovskites have advanced tremendously over the last decade, producing LEDs with external quantum efficiency (EQE) over 20 % for both red and green. Here we report our ongoing work to improve the EQE, color and photo-stability of these devices, and the emission properties of perovskite nanocrystals. In particular, we report several findings that enable us to produce higher quantum yield, deeper blue, and more highly confined perovskite nanocrystals, nanorods and nanoplatelets for use in LEDs and other emission applications. Since the toxicity and instability of lead halide perovskites may still limit their applications, we have also prepared lead-free ternary metal halide nanocrystals for emission applications. These self-trapped excitonic (STE) emitters, as nano-, micro- or single crystals can be produced as highly luminescent, long-lived emitters with red to near-IR emission peaks.