Spectral Stable Blue-Light-Emitting Diodes via Asymmetric Organic Diamine Based Dion–Jacobson Perovskites
Yuqiang Liu, Luis K. Ono, Guoqing Tong, Tongle Bu, Hui Zhang, Chenfeng Ding, Wei Zhang, Yabing Qi
Abstract
perovskite via introduction of an asymmetric molecular configuration as the organic spacer cation in perovskites. The primary and tertiary ammonium groups on the asymmetric cations bridge with the lead halide octahedra forming the DJ phase structures. Stable photoluminescence spectra were demonstrated in perovskite films owing to the suppressed halide segregation. Meanwhile, the radiative recombination efficiency of charges is improved significantly as a result of the confinement effects and passivation of charge traps. Finally, we achieved an external quantum efficiency of 2.65% in blue PeLEDs with stable spectra emission under applied bias voltages. To our best knowledge, this is the first report of asymmetric cations used in PeLEDs, which provides a facile solution to the halide segregation issue in PeLEDs.