Adv. Mater.: Open-shell Diradical-sensitized Electron Transport Layer for High-Performance Colloidal Quantum Dot Solar Cells

Title：

Open-shell Diradical-sensitized Electron Transport Layer for High-Performance Colloidal Quantum Dot Solar Cells

Authors：

Shiwen Fang^1,2#, Jiaxing Huang^3#, Ran Tao¹, Qi Wei³, Xiaobo Ding¹, Shota Yajima⁴, Zhongxin Chen³,Weiya Zhu³, Cheng Liu¹, Yusheng Li⁴, Ni Yin⁵, Leliang Song¹,Yang Liu¹, Guozheng Shi¹,Hao Wu¹, Yiyuan Gao¹,Xin Wen¹, Qi Chen⁵,Qing Shen⁴, Youyong Li¹, Zeke Liu^1,2*, Yuan Li³* and Wanli Ma^1,2*

Institutions：

¹Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute ofFunctional Nano & Soft Materials (FUNSOM), Joint International Research Laboratory of Carbon-Based Functional Materials and Devices, Soochow University, 199 Ren'ai Road, Suzhou, 215123, Jiangsu, China

²Jiangsu Key Laboratory of Advanced Negative Carbon Technologies, Soochow University, Suzhou, 215123, Jiangsu, PR China

³Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, P. R. China.

⁴Faculty of Informatics and Engineering, The University of Electro-Communications, 1-5-1 Chofugaoka, Chofu, Tokyo 182-8585, Japan.

⁵i-Lab, CAS Key Laboratory of Nanophotonic Materials and Devices, Suzhou Institute of Nano-Tech and Nano-Bionics, Suzhou 215123, China

Abstract：

The zinc oxide (ZnO) nanoparticles (NPs) are well-documented as an excellent electron transport layer (ETL) in optoelectronic devices. However, the intrinsic surface flaw of the ZnO NPs can easily result in serious surface recombination of carriers. Exploring effective passivation methods of ZnO NPs is essential to maximize the device's performance. Herein, a hybrid strategy is explored for the first time to improve the quality of ZnO ETL by incorporating stable organic open-shell donor-acceptor type diradicaloids. The high electron-donating feature of the diradical molecules can efficiently passivate the deep-level trap states and improve the conductivity of ZnO NP film. The unique advantage of the radical strategy is that its passivation effectiveness is highly correlated with the electron-donating ability of radical molecules, which can be precisely controlled by the rational design of molecular chemical structures. The well-passivated ZnO ETL is applied in lead sulfide (PbS) colloidal quantum dot solar cells, delivering a power conversion efficiency of 13.54%. More importantly, as a proof-of-concept study, this work will inspire the exploration of general strategies using radical molecules to construct high-efficiency solution-processed optoelectronic devices.

IF：

32.086

Link：

https://onlinelibrary.wiley.com/doi/10.1002/adma.202212184