@article{Cao2025, 
author = {Xiaoyu Cao and Hongzheng Dong and Kaijian Zhu and Qiyu Qu and Dongjian Jiang and Yuzhan Zheng and Changping Yao and Bo Wang and Fatwa F. Abdi and Wenjun Luo and Zhigang Zou},
title = {Enhanced performance of quantum-dot-sensitized solar cells by suppressing back transfer in TiO2/CdS faradaic junction photoelectrode},
year = {2025},
journal = {Nano Research},
volume = {18},
number = {6},
pages = {94907455},
keywords = {TiO2/CdS heterojunction, back transfer, interfacial charge transfer mechanism, Gd(OH)3 treatment},
url = {https://www.sciopen.com/article/10.26599/NR.2025.94907455},
doi = {10.26599/NR.2025.94907455},
abstract = {Quantum-dot-sensitized solar cells (QDSSCs) represent a promising technology for efficient solar energy conversion, benefiting from multiple exciton generation and solution-based fabrication. However, interface recombination remains a major barrier to performance enhancement, particularly the back transfer of photo-generated electrons to the electrolyte. In this study, we identify that charge transfer at the TiO2/CdS interface does not occur through the conduction band but rather via the faradaic layer of TiO2, which plays a pivotal role in back electron transfer. To address this issue, we introduce a uniform Gd(OH)3 thin film on the surface of TiO2 by a successive ionic layer adsorption and reaction (SILAR) method, which effectively inhibits back transfer by reducing polysulfides (Sn2−) reduction, leading to a substantial improvement in the short-circuit current density (JSC) and open-circuit voltage (VOC). Using techniques such as transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), in situ Raman and in situ ultraviolet–visible (UV–vis), we clarify the interfacial charge transfer mechanism, demonstrating how the Gd3+ treatment effectively suppresses the back reaction. This work provides a simple approach to improve QDSSCs performance and offers valuable insights for optimizing other photoelectrode materials.}
}