Manganese Doped Tin Oxide for Stable and Efficient Quantum Dot Light–Emitting Diodes
Wenchen Ma, Zhenwei Ren, Hengfei Shi, Xueqing Xia, Xinwen Wang, Huifei Ji, Hua Chen, Chengzhao Luo, Chinhua Wang, Song Chen, Yu Chen
Abstract
Abstract As an alternative electron transport material to the chemically unstable ZnO nanoparticles (NPs), SnO 2 NPs exhibit a great potential to construct high‐performance quantum dot light‐emitting diodes (QLEDs). However, only moderate device performance has been obtained for SnO 2 ‐based QLEDs due to the low electron mobility, unfavorable energy band, and massive defects of SnO 2 NPs. Herein, a strategy of transition metal doping is reported to achieve high‐quality manganese‐doped SnO 2 (Mn‐SnO 2 ) NPs to address the above problems. Specifically, the large bond energy of Mn─O bonds reduces the oxygen vacancy defects, prompting an effective suppression of the interfacial exciton quenching for massive radiative recombination. Moreover, the favorable energy band and high electron mobility for Mn‐SnO 2 promote efficient electron injection and transportation. The good optoelectronic properties for Mn‐SnO 2 NPs contribute to a great enhancement in device efficiency from 8.2 to 11.4% and a remarkable improvement in lifetime ( T 95 ) from 565.3 to 1009.2 h at 1000 cd −2 , among the best performing ZnO‐free QLEDs. Notably, the Mn‐SnO 2 based QLEDs show a very superior shelf stability to the QLEDs based on SnO 2 and ZnO analogs. Consequently, this work reports an effective approach to achieve high‐quality SnO 2 NPs for efficient and stable QLEDs.