Defect passivation with novel silicone copolymers for efficient perovskite light-emitting diodes

Authors：He, Fangru^*; Liu, Zhe; Qing, Jian; Zhao, Xinxin; Liu, Xinyan; Ma, Fulong; Dai, Yanpeng; Su, Shi-Jian; Hou, Lintao; Qi, Zhengjian

Source：Journal of Physics D - Applied Physics, 2021, 54(7): 074005.

DOI：10.1088/1361-6463/abc4a9

• perovskite light-emitting diodes
• silicone copolymers
• amphiphilic
• passivation

Pinhole-free perovskite films with low defect density are essential to boost the efficiency of metal halide perovskite light-emitting diodes (PeLEDs). In this work, a novel amphiphilic silicone copolymer (Si-14-PEG(14)-QAC) is introduced into perovskite as a passivation agent to improve the performance of PeLEDs. Si-14-PEG(14)-QAC possesses polyethylene glycol and -NCH3 units, which can interact with perovskite by hydrogen bonding, resulting in high-quality perovskite films with small-size crystals, high coverage, low defect density, and enhanced photoluminescence quantum yield. Consequently, the perovskite films with Si-14-PEG(14)-QAC enable efficient green PeLEDs with an external quantum efficiency of 4.5%, which is much higher than that of the control device without the polymer passivator (0.86%). This work suggests the great potential of silicone copolymers as passivation agents for high-quality perovskite films with high performance.