Efficient Thermally Evaporated Perovskite Light-Emitting Devices via a Bilateral Interface Engineering Strategy
Li Song, Lixin Huang, Yuan Liu, Xiaoyang Guo, Chong Geng, Shu Xu, Yuanqin Xia, Yuan Zhang, Nannan Luan, Yongsheng Hu
Abstract
Physical vapor deposition has emerged as a promising strategy for efficient and stable all-inorganic perovskite light-emitting devices (PeLEDs). However, the thermally evaporated PeLEDs still suffer from unsatisfactory optoelectrical performance because of the massive nonradiative defects. Herein, we demonstrate an efficient bilateral interfacial defect-passivation strategy toward high-performance PeLEDs with a thermally deposited CsPbBr3 emissive layer (EML). Specifically, the nonradiative defects from the bulk as well as the EML/charge transport layer (CTL) interface are significantly suppressed by implementing the 3-amino-1-propanol (3AP)-modified PEDOT:PSS and introducing ammonium salts, respectively. Simultaneously, both the 3AP induced less-conductive Cs4PbBr6 and ammonium salts can balance the charge injection into the EML effectively. As a result, we achieved efficient PeLEDs based on thermally evaporated CsPbBr3 with a luminance of 15745 cd/m2, current efficiency of 32 cd/A, external quantum efficiency of 8.86%, and lifetime of 3.74 h. The strategy proposed here may shed light on the development of highly efficient thermally evaporated PeLEDs.