High-Performance All-Inorganic Architecture Perovskite Light-Emitting Diodes Based on Tens-of-Nanometers-Sized CsPbBr3 Emitters in a Carrier-Confined Heterostructure

作者：Xinquan Gong, Xiaoming Hao, Junjie Si, Yunzhou Deng, Kai An, Qianqing Hu, Qiuting Cai, Yun Gao, You Ke, Nana Wang, Zhuopeng Du, Muzhi Cai, Zhizhen Ye, Xingliang Dai, Zugang Liu · 发表于：ACS Nano · 年份：2024 · DOI：10.1021/acsnano.3c09004 · 被引用次数：30 · 研究领域：Perovskite Materials and Applications、Organic Light-Emitting Diodes Research、2D Materials and Applications

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 CsPbBr 3 (TNS-CsPbBr 3 ) 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-CsPbBr 3 crystals and wide-bandgap Cs 4 PbBr 6 within a grain is formed by carefully controlling the precursor ratio. These heterostructured TNS-CsPbBr 3 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 degradat...