Enhancing the performance of perovskite light-emitting devices through 1,3,5-tris(2--phenylbenzimidazolyl)benzene interlayer incorporation.

Interface engineering is important for enhancing the luminance efficiency and stability of perovskite light-emitting devices. In this work, we study the effects of spin-coated 1,3,5-tris(2--phenylbenzimidazolyl)benzene (TPBi) layer incorporation on the crystal structure, morphology, photo-physics, and charge transport characteristics of the underlying MAPbBr layer. Introduction of such a TPBi interlayer effectively reduces defect density and increases radiative recombination in the MAPbBr layer. Related perovskite light-emitting devices with a TPBi interlayer show a maximum external quantum efficiency of 9.9% and power efficiency of 22.1 lm W, which are 2.0 and 1.6 times those of the devices without a TPBi interlayer, respectively. The study provides a simple and effective method to enhance the performance of perovskite light-emitting devices.