钙钛矿(结构)
纳米
量子效率
材料科学
光电子学
异质结
发光二极管
二极管
亮度
电致发光
图层(电子)
纳米技术
光学
化学
结晶学
物理
复合材料
作者
Xinquan Gong,Xiaoming Hao,Junjie Si,Yunzhou Deng,Kai Nan An,Qianqing Hu,Qiuting Cai,Yun Gao,You Ke,Nana Wang,Zhuopeng Du,Muzhi Cai,Zhizhen Ye,Xingliang Dai,Zugang Liu
出处
期刊:ACS Nano
[American Chemical Society]
日期:2024-03-12
标识
DOI:10.1021/acsnano.3c09004
摘要
Developing green perovskite light-emitting diodes (PeLEDs) with a high external quantum efficiency (EQE) and low efficiency roll-off at high brightness remains a critical challenge. Nanostructured emitter-based devices have shown high efficiency but restricted ascending luminance at high current densities, while devices based on large-sized crystals exhibit low efficiency roll-off but face great challenges to high efficiency. Herein, we develop an all-inorganic device architecture combined with utilizing tens-of-nanometers-sized CsPbBr3 (TNS-CsPbBr3) emitters in a carrier-confined heterostructure to realize green PeLEDs that exhibit high EQEs and low efficiency roll-off. A typical type-I heterojunction containing TNS-CsPbBr3 crystals and wide-bandgap Cs4PbBr6 within a grain is formed by carefully controlling the precursor ratio. These heterostructured TNS-CsPbBr3 emitters simultaneously enhance carrier confinement and retain low Auger recombination under a large injected carrier density. Benefiting from a simple device architecture consisting of an emissive layer and an oxide electron-transporting layer, the PeLEDs exhibit a sub-bandgap turn-on voltage of 2.0 V and steeply rising luminance. In consequence, we achieved green PeLEDs demonstrating a peak EQE of 17.0% at the brightness of 36,000 cd m-2, and the EQE remained at 15.7% and 12.6% at the brightness of 100,000 and 200,000 cd m-2, respectively. In addition, our results underscore the role of interface degradation during device operation as a factor in device failure.
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