Ji Yongqiang, Zhong Qixuan, Yang Xiaoyu, Li Lei, Li Qiuyang, Xu Hongyu, Chen Peng, Li Shunde, Yan Haoming, Xiao Yun, Xu Fan, Qiu Hengwei, Gong Qihuang, Zhao Lichen, Zhu Rui
State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Frontiers Science Center for Nano-optoelectronics & Collaborative Innovation Center of Quantum Matter, Peking University, Beijing 100871, China.
Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 3PU, U.K.
Nano Lett. 2024 Aug 28;24(34):10418-10425. doi: 10.1021/acs.nanolett.4c00959. Epub 2024 Aug 19.
Surface ligand chemistry is vital to control the synthesis, diminish surface defects, and improve the electronic coupling of quantum dots (QDs) toward emerging applications in optoelectronic devices. Here, we successfully develop highly homogeneous and dispersed AgBiS QDs, focus on the control of interdot spacing, and substitute the long-chain ligands with ammonium iodide in solution. This results in improved electronic coupling of AgBiS QDs with excellent surface passivation, which greatly facilitates carrier transport within the QD films. Based on the stable AgBiS QD dispersion with the optimal ligand state, a homogeneous and densely packed QD film is prepared by a facile one-step coating process, delivering a champion power conversion efficiency of approximately 8% in the QD solar cells with outstanding shelf life stability. The proposed surface engineering strategy holds the potential to become a universal preprocessing step in the realm of high-performance QD optoelectronic devices.
表面配体化学对于控制量子点（QD）的合成、减少表面缺陷以及改善其在光电器件新兴应用中的电子耦合至关重要。在此，我们成功开发出高度均匀且分散的AgBiS量子点，着重控制量子点间间距，并在溶液中用碘化铵替代长链配体。这使得AgBiS量子点的电子耦合得到改善，表面钝化效果优异，极大地促进了量子点薄膜内的载流子传输。基于具有最佳配体状态的稳定AgBiS量子点分散体，通过简便的一步涂布工艺制备出均匀且紧密堆积的量子点薄膜，在量子点太阳能电池中实现了约8%的最佳功率转换效率，且具有出色的储存寿命稳定性。所提出的表面工程策略有望成为高性能量子点光电器件领域的通用预处理步骤。
