High-Performance Green Light-Emitting Diodes Based on MAPbBr3–Polymer Composite Films Prepared by Gas-Assisted Crystallization

The morphology of perovskite films has a significant impact on luminous characteristics of perovskite light-emitting diodes (PeLEDs). To obtain a highly uniform methylammonium lead tribromide (MAPbBr3) film, a gas-assisted crystallization method is introduced with a mixed solution of MAPbBr3 precursor and polymer matrix. The ultrafast evaporation of the solvent causes a high degree of supersaturation which expedites the generation of a large number of nuclei to form a MAPbBr3–polymer composite film with full surface coverage and nano-sized grains. The addition of the polymer matrix significantly affects the optical properties and morphology of MAPbBr3 films. The PeLED made of the MAPbBr3–polymer composite film exhibits an outstanding device performance of a maximum luminance of 6800 cd·m–2 and a maximum current efficiency of 1.12 cd·A–1. Furthermore, 1 cm2 area pixel of PeLED displays full coverage of a strong green electroluminescence, implying that the high-quality perovskite film can be useful for larg...