@article{Wang2026, 
author = {Lishuang Wang and Guofa Li and Renjie Xiang and Huahao Wu and Zurong Huang and Shuya Huang and Zhaobing Tang and Xiaoyang Guo and Daocheng Pan and Heng Zhang and Jialong Zhao and Bingsuo Zou},
title = {Over 30% efficient and highly stable Co-SnO2-based QLEDs through ultrathin MgCl2 interface engineering},
year = {2026},
journal = {Nano Research},
keywords = {external quantum efficiency (EQE), Co doped tin oxide, quantum dot light-emitting diodes (QLEDs), MgCl2 interlayer, interface engineering},
url = {https://www.sciopen.com/article/10.26599/NR.2026.94909019},
doi = {10.26599/NR.2026.94909019},
abstract = {SnO2-based quantum dot light-emitting diodes (QLEDs) offer superior environmental stability over ZnO-based devices, yet their electroluminescent performance is often limited by interfacial exciton quenching and unbalanced carrier injection. Here, we employed solution-processed Co-doped SnO2 (CSO) nanoparticles as the electron transport layer to reduce oxygen vacancies and optimize energy-level alignment. As a result, the red QLED with 5wt% CSO achieved an external quantum efficiency (EQE) of 21.5% at a luminance of 187 cd/m2. However, at high luminance the carrier-balance improvement cannot be maintained and the CSO-device still shows significant efficiency roll-off. To further optimize the interface, we introduced an ultrathin MgCl2 interlayer between the quantum dot layer and the CSO layer. The MgCl2 layer acts as a functional modifier, passivating surface defects, tuning energy levels, and improving carrier balance. Consequently, the device achieved a maximum EQE exceeding 30% and a long operational lifetime (T95 at 1000 cd/m2) of 3367.7 h. This synergistic strategy provides a practical pathway toward high-performance and stable QLEDs.}
}