Intrinsic white-light emission from low-dimensional perovskites for white-light-emitting diodes with high-color-rendering index

Abstract

High-performance white-light-emitting diodes (WLEDs) are regarded as a promising next-generation solid-state light source. However, a low-color-rendering index (CRI), consumption of rare-earth elements, and inevitable self-absorption remain the major challenges for high-performance WLEDs. Here, lead-doped Cs3Cu2Br5 nanocrystals (NCs) with a zero-dimensional structure are prepared to facilitate stable and intrinsic white-light emission (IWE) without phosphors and other compositions. The lead dopants are expected to be centers of isolated [PbBr6] octahedrons, in which self-trapped excitons originating from distorted octahedra can form. Subsequently, a broadband blue photoluminescence (PL) from the Cs3Cu2Br5 and a broadband red PL from the lead doping are observed, exhibiting intrinsic white-light emission overall. The doped Cs3Cu2Br5 NCs are then employed to fabricate WLEDs, which possess a high CRI of 98 and an excellent 200-h operating stability.