Efficient single-component white light emitting diodes enabled by lanthanide ions doped lead halide perovskites via controlling Förster energy transfer and specific defect clearance
Rui Sun, Donglei Zhou, Yujiao Ding, Yue Wang, Yuqi Wang, Xinmeng Zhuang, Shuainan Liu, Nan Ding, Tianyuan Wang, Wen Xu, Hongwei Song
Abstract
Abstract Currently, a major challenge for metal-halide perovskite light emitting diodes (LEDs) is to achieve stable and efficient white light emission due to halide ion segregation. Herein, we report a promising method to fabricate white perovskite LEDs using lanthanide (Ln 3+ ) ions doped CsPbCl 3 perovskite nanocrystals (PeNCs). First, K + ions are doped into the lattice to tune the perovskite bandgap by partially substituting Cs + ions, which are well matched to the transition energy of some Ln 3+ ions from the ground state to the excited state, thereby greatly improving the Förster energy transfer efficiency from excitons to Ln 3+ ions. Then, creatine phosphate (CP), a phospholipid widely found in organisms, serves as a tightly binding surface-capping multi-functional ligand which regulates the film formation and enhances the optical and electrical properties of PeNC film. Consequently, the Eu 3+ doped PeNCs based-white LEDs show a peak luminance of 1678 cd m -2 and a maximum external quantum efficiency (EQE) of 5.4%, demonstrating excellent performance among existing white PeNC LEDs from a single chip. Furthermore, the method of bandgap modulation and the defect passivation were generalized to other Ln 3+ ions doped perovskite LEDs and successfully obtained improved electroluminescence (EL). This work demonstrates the comprehensive and universal strategies in the realization of highly efficient and stable white LEDs via single-component Ln 3+ ions doped PeNCs, which provides an optimal solution for the development of low-cost and simple white perovskite LEDs.