Lattice-matched molecular-anchor design for high-performance perovskite quantum dot light-emitting diodes
Jiawei Chen, Xiangyu Liu, Bo Cai, Yuanzhuang Cheng, Hao Wen, Danlei Zhu, Yaonan Xiong, Linjie Dai, Xinghua Yan, Baixu Xiang, Xiyu Luo, Wenjing Feng, Jiuyao Du, Shuyue Dong, Qingsong Shan, Shulin Chen, Haibo Zeng, Qihua Xiong, Lian Duan, Dongxin Ma
Abstract
Perovskite quantum dot light-emitting diodes have rapidly achieved high external quantum efficiencies of over 25%; however, hindered by limited operating stability originating from surface defects or ion migration in quantum dots. Here, we design a lattice-matched anchoring molecule, tris(4-methoxyphenyl)phosphine oxide (TMeOPPO-p), to anchor the multi-site defects and stabilise the lattice. The target quantum dots exhibit high exciton recombination features with near-unity photoluminescence quantum yields (97%), and the as-fabricated quantum dot light-emitting diodes present a maximum external quantum efficiency of up to 27% at 693 nm, a low efficiency roll-off (over 20% at a current density of 100 mA cm−2 for the typical device) and an operating half-life of over 23,000 h. Besides, the air-processed devices maintain a maximum external quantum efficiency of over 26% with good storage stability. We expect this work to exert a profound influence on rational and on-demand molecule design for perovskite QDs, indicating great promise in optoelectronic applications. Chen et al. report a lattice-matched molecule, tris(4-methoxyphenyl) phosphine oxide, to anchor multi-site defects and stabilise the lattice of perovskite quantum dots, enabling deep-red LEDs with efficiency up to 26.91% at 693 nm. The air-processed devices can still maintain an efficiency of 26.28%.