Phase dimensions resolving of efficient and stable perovskite light-emitting diodes at high brightness

The efficiency and stability issues of perovskite light-emitting diodes, especially at high brightness, need to be urgently solved for displays and lighting applications. Herein we present a simple chemical washing method called solvent sieve to resolve the phase dimension issue of metal halide perovskites. After being sieved, undesirable defect-rich low-n phases are selectively screened out of perovskite multi-quantum-well structures. With better intrinsic structure refinement, the sieved perovskites demonstrated not only a record external quantum efficiency, current efficiency, and T50 lifetime of 29.5%, 127.4 cd A-1, and 18.67 h at 12,000 cd m-2 (the equivalent of over 50,317 h or 5.7 years at 100 cd m-2), respectively, with a maximum luminance of over 147,872.8 cd m-2, but also extraordinary resistance to air and moisture, maintaining over 75% of film photoluminescence quantum yield and 80% of device EQE after being stored at ambience for 100 days. The simple solvent sieve treatment we reported here confirms the feasibility of metal halide perovskites for luminescence and unleashes the efficiency and stability potentials of high-brightness perovskite light-emitting diodes for future commercial applications. A chemical washing method called solvent sieve is developed to resolve the phase dimension issue of metal halide perovskites. The sieved perovskites demonstrate a record external quantum efficiency of 29.5% and a T50 lifetime of 18.67 h at 12,000 cd m-2; 80% of the device external quantum efficiency lasts for 100 days in the ambient.