Thermodynamics-Induced Injection Enhanced Deep-Blue Perovskite Quantum Dot LEDs
Cheng Yan, Chao Luo, Wen Li, Xiaodong Peng, Jingjing Cao, Xiankan Zeng, Yue Gao, Xuehai Fu, Xiang Chu, Wen Deng, Fengjun Chun, Shiyu Yang, Qungui Wang, Weiqing Yang
Abstract
Precisely tuning emission spectra through the component control of mixed halides has been proved to be an efficient method for procuring deep-blue perovskite LEDs (PeLEDs). However, the inferior color instability and lifetime attenuation, originated from vacancy- and trap-mediated mechanisms under an external field, remain an uninterruptedly formidable challenge for the commercial development of PeLEDs. Here, an ultrafast thermodynamics-induced injection enhancement strategy was employed to promote efficient carrier recombination within perovskite quantum dots (QDs), accompanied by less inefficient charge accumulation and trap generation, enabling deep-blue PeLEDs with improved thermal and spectral stability. The resultant PeLEDs feature an external quantum efficiency (EQE) of 3.66%, a max luminance of 2100 cd/m2 at the electroluminescence (EL) of 460 nm, and a halftime of 288 s. This work provides a general platform for promoting the EL performances and a deep insight into unraveling the degradation mechanism of blue PeLEDs.