All-vacuum fabrication of yellow perovskite light-emitting diodes

• 作者: Jinghui Li Longbo Yang Qingxun Guo Peipei Du Liang Wang Xue Zhao Nian Liu Xuke Yang Jiajun Luo Jiang Tang
• 来源期刊: 科学通报（英文版）
• 年，卷（期）: 2022,（2）
• 所属期刊栏目: ARTICLES
• 页码范围: 178-185
• 页数: 8页
• 语种: 英文

摘要

Yellow light-emitting diodes (LEDs) are widely utilized in high-quality lighting,light communication,indicator lamps,etc.Owing to their outstanding material properties and device performance,the metal halide perovskites have demonstrated a significant potential for LED applications.However,the perfor-mance of the yellow perovskite LEDs (PeLEDs) is inferior to that of their green and red counterparts,with the maximum external quantum efficiency (EQE) limited to ～3.1％.Further,a majority of the yellow PeLEDs are fabricated using the spin-coating methods.The current study reports the development of the yellow CsPbBr2I PeLEDs based on an all-vacuum deposition approach,which has been widely employed in the commercial organic LEDs (OLEDs).By controlling the co-evaporation rate of CsI and PbBr2,the growth kinetics of the perovskite layer are regulated to achieve a small grain size of～31.8 nm.Consequently,an improved radiative recombination rate (8.04 × 10-9 cm3/s) is obtained owing to the spatial confinement effect.The PeLEDs based on the optimal perovskite film demonstrate the yellow electroluminescence (574 nm) with a maximum EQE of ～3.7％ and luminance of～16,200 cd/m2,thus,representing one of the most efficient and bright yellow PeLEDs.Overall,this study provides a useful guideline for realizing the efficient PeLEDs based on the thermal evaporation strategy and highlights the potential of PeLED as an efficient and bright yellow light source.