Synthesis of a library of white light-emitting perovskites

A strict barrier regulation strategy was developed for the synthesis of broadband white light-emitting perovskites. This study was led by Professor Jun Xing (College of Molecular Chemistry and Engineering, Qingdao University of Science and Technology) and Professor Weigao Xu (College of Chemistry and Chemical Engineering, Nanjing University).

The authors revealed the effect of molecular composition on structural distortion of perovskites and devised a stringent barrier regulation strategy to synthesize predictably broadband white light-emitting perovskites. Spacer molecules containing CC (-NH₂) – C group was applied to synthesize 2D perovskites, which introduces large spacer hindrance in the in-plane direction and induces structural deformation.

The degree of structural deformation in perovskites can be regulated by controlling CC (-NH₂) -C bond angle of the molecule, which determines the self-trapping free excitons. The as-synthesized perovskites exhibit tunable broadband emission from 400 to 800 nm, and larger molecular hindrance leads to greater structural distortion and a higher rate of self-trapping excitons, resulting in cool to warm white light.

According to this strategy, functional molecules can be extended to secondary and tertiary amines with group C-NH_x-C and 40 types of perovskites with broadband emission were successfully synthesized. This work opens a general avenue for the directed synthesis of white light-emitting perovskites and reveals the relationship between molecular hindrance, structural deformation and STEs in perovskites.

The paper has been published in the journal China Chemistry Science.