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Vol. 17 (2025)

Revealing the Role of Hydrogen in Highly Efficient Ag-Substituted CZTSSe Photovoltaic Devices: Photoelectric Properties Modulation and Defect Passivation

https://doi.org/10.1007/s40820-024-01574-3
Xiaoyue Zhao
The Key Laboratory for Special Functional Materials of MOE, School of Nanoscience and Materials Engineering, National and Local Joint Engineering Research Center for High‑Efficiency Display and Lighting Technology, Collaborative Innovation Center of Nano Functional Materials and Applications, Henan University, Kaifeng 475004, People’s Republic of China
Jingru Li
The Key Laboratory for Special Functional Materials of MOE, School of Nanoscience and Materials Engineering, National and Local Joint Engineering Research Center for High‑Efficiency Display and Lighting Technology, Collaborative Innovation Center of Nano Functional Materials and Applications, Henan University, Kaifeng 475004, People’s Republic of China
Chenyang Hu
The Key Laboratory for Special Functional Materials of MOE, School of Nanoscience and Materials Engineering, National and Local Joint Engineering Research Center for High‑Efficiency Display and Lighting Technology, Collaborative Innovation Center of Nano Functional Materials and Applications, Henan University, Kaifeng 475004, People’s Republic of China
Yafang Qi
The Key Laboratory for Special Functional Materials of MOE, School of Nanoscience and Materials Engineering, National and Local Joint Engineering Research Center for High‑Efficiency Display and Lighting Technology, Collaborative Innovation Center of Nano Functional Materials and Applications, Henan University, Kaifeng 475004, People’s Republic of China
Zhengji Zhou
The Key Laboratory for Special Functional Materials of MOE, School of Nanoscience and Materials Engineering, National and Local Joint Engineering Research Center for High‑Efficiency Display and Lighting Technology, Collaborative Innovation Center of Nano Functional Materials and Applications, Henan University, Kaifeng 475004, People’s Republic of China
Dongxing Kou
The Key Laboratory for Special Functional Materials of MOE, School of Nanoscience and Materials Engineering, National and Local Joint Engineering Research Center for High‑Efficiency Display and Lighting Technology, Collaborative Innovation Center of Nano Functional Materials and Applications, Henan University, Kaifeng 475004, People’s Republic of China
Wenhui Zhou
The Key Laboratory for Special Functional Materials of MOE, School of Nanoscience and Materials Engineering, National and Local Joint Engineering Research Center for High‑Efficiency Display and Lighting Technology, Collaborative Innovation Center of Nano Functional Materials and Applications, Henan University, Kaifeng 475004, People’s Republic of China
Shengjie Yuan
The Key Laboratory for Special Functional Materials of MOE, School of Nanoscience and Materials Engineering, National and Local Joint Engineering Research Center for High‑Efficiency Display and Lighting Technology, Collaborative Innovation Center of Nano Functional Materials and Applications, Henan University, Kaifeng 475004, People’s Republic of China
Sixin Wu
The Key Laboratory for Special Functional Materials of MOE, School of Nanoscience and Materials Engineering, National and Local Joint Engineering Research Center for High‑Efficiency Display and Lighting Technology, Collaborative Innovation Center of Nano Functional Materials and Applications, Henan University, Kaifeng 475004, People’s Republic of China

Corresponding Author: Sixin Wu

wusixin@henu.edu.cn

Nano-Micro Letters, Vol. 17 (2025), Article Number: 84

Abstract

The presence of SnZn-related defects in Cu2ZnSn(S,Se)4 (CZTSSe) absorber results in large irreversible energy loss and extra irreversible electron–hole non-radiative recombination, thus hindering the efficiency enhancement of CZTSSe devices. Although the incorporation of Ag in CZTSSe can effectively suppress the SnZn-related defects and significantly improve the resulting cell performance, an excellent efficiency has not been achieved to date primarily owing to the poor electrical-conductivity and the low carrier density of the CZTSSe film induced by Ag substitution. Herein, this study exquisitely devises an Ag/H co-doping strategy in CZTSSe absorber via Ag substitution programs followed by hydrogen-plasma treatment procedure to suppress SnZn defects for achieving efficient CZTSSe devices. In-depth investigation results demonstrate that the incorporation of H in Ag-based CZTSSe absorber is expected to improve the poor electrical-conductivity and the low carrier density caused by Ag substitution. Importantly, the C=O and O–H functional groups induced by hydrogen incorporation, serving as an electron donor, can interact with under-coordinated cations in CZTSSe material, effectively passivating the SnZn-related defects. Consequently, the incorporation of an appropriate amount of Ag/H in CZTSSe mitigates carrier non-radiative recombination, prolongs minority carrier lifetime, and thus yields a champion efficiency of 14.74%, showing its promising application in kesterite-based CZTSSe devices.


Highlights:
1 The Ag/H co-doping strategy has been proposed to promote the performance of Cu2ZnSn(S,Se)4 (CZTSSe) devices.
2 The incorporation of H in Ag-based CZTSSe photovoltaic absorber is expected to improve the poor electrical conductivity and the low carrier density caused by Ag substitution.
3 Benefiting from the synergism of the excellent defect passivation effect and photoelectric properties complementary effect enabled by Ag/H co-doping, a champion device with 14.74% efficiency is achieved.

Keywords

CZTSSe Ag/H co-doping Photoelectric properties modulation Defect passivation Non-radiative recombination
Zhao, Xiaoyue, Jingru Li, Chenyang Hu, Yafang Qi, Zhengji Zhou, Dongxing Kou, Wenhui Zhou, Shengjie Yuan, and Sixin Wu. 2024. “Revealing the Role of Hydrogen in Highly Efficient Ag-Substituted CZTSSe Photovoltaic Devices: Photoelectric Properties Modulation and Defect Passivation”. Nano-Micro Letters 17 (December):84. https://doi.org/10.1007/s40820-024-01574-3.
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