He Yarong, Yan Jiaxu, Xu Lei, Zhang Bangmin, Cheng Qian, Cao Yu, Zhang Ju, Tao Cong, Wei Yingqiang, Wen Kaichuan, Kuang Zhiyuan, Chow Gan Moog, Shen Zexiang, Peng Qiming, Huang Wei, Wang Jianpu
Key Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing, 211816, China.
Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore.
Adv Mater. 2021 Apr;33(14):e2006302. doi: 10.1002/adma.202006302. Epub 2021 Mar 3.
Room-temperature-high-efficiency light-emitting diodes based on metal halide perovskite FAPbI are shown to be able to work perfectly at low temperatures. A peak external quantum efficiency (EQE) of 32.8%, corresponding to an internal quantum efficiency of 100%, is achieved at 45 K. Importantly, the devices show almost no degradation after working at a constant current density of 200 mA m for 330 h. The enhanced EQEs at low temperatures result from the increased photoluminescence quantum efficiencies of the perovskite, which is caused by the increased radiative recombination rate. Spectroscopic and calculation results suggest that the phase transitions of the FAPbI play an important role for the enhancement of exciton binding energy, which increases the recombination rate.
基于金属卤化物钙钛矿FAPbI的室温高效发光二极管被证明能够在低温下完美工作。在45K时实现了32.8%的峰值外量子效率（EQE），对应于100%的内量子效率。重要的是，这些器件在200 mA m的恒定电流密度下工作330小时后几乎没有退化。低温下EQE的提高源于钙钛矿光致发光量子效率的增加，这是由辐射复合率的增加引起的。光谱和计算结果表明，FAPbI的相变对激子结合能的增强起着重要作用，从而提高了复合率。
