Highly efficient white-light emission in a polar two-dimensional hybrid perovskite

Broadband white-light emission was realized in a polar two-dimensional hybrid perovskite, (2meptH2)PbBr4 (2mept = 2-methyl-1,5-diaminopentane). The white-light emission originates from self-trapped excitons owing to the distortion-induced polar structure. Notably, it exhibits a high photoluminescence quantum efficiency of 3.37% and an ultrahigh colour rendering index of 91.