Gradient Conduction Band Energy Engineering Driven High‐Efficiency Solution‐Processed Cu2ZnSn(S, Se)4/ZnxCd1–x S Solar Cells. (4th November 2022)

• Record Type: Journal Article
• Authors: Xu, Zhen; Gao, Qianqian; Cui, Changcheng; Yuan, Shengjie; Kou, Dongxing; Zhou, Zhengji; Zhou, Wenhui; Meng, Yuena; Qi, Yafang; Ishaq, Muhammad; Shah, Usman Ali; Wu, Sixin
• Is Part Of: Advanced functional materials. Volume 33:Number 3(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-11-04
• Subjects: CZTSSe -- gradient band structures -- interface engineering -- solar cells -- Zn‐doping CdS; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.202209187
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: The photovoltaic performance of the environmentally friendly Cu2 ZnSn(S, Se)4 (CZTSSe) solar cells is lower than its predecessor Cu(In, Ga)Se2 solar cells. Severe carrier recombination at the CZTSSe/CdS interface is one major reason that results in a large open‐circuit voltage loss. Doping zinc into CdS is a feasible strategy to modifying the CdS buffer layer film, but the present methods are not satisfactory. In this study, novel zinc incorporation strategy is developed to deposit a gradient composition ternary Znx Cd1–x S buffer layer for optimizing the heterojunction interface. The application of gradient composition Znx Cd1–x S buffer layer constructs a gradient conduction band energy configuration in the CZTSSe/buffer layer interface, which highly reduces the interface recombination. The suppressed interface recombination contributes to the enhanced open circuit voltage and device performance. Consequently, the CZTSSe solar cell based on gradient composition Znx Cd1–x S buffer layers achieves champion efficiency of 12.35% with V OC of 504.81 mV, J SC of 36.90 mA cm −2, and FF of 66.28%. It is worth noting that flammable and the toxic hydrazine solvent are replaced by the safe and low‐toxic 2‐methoxyethanol, making it more promising for the future commercialization of CZTSSe solar cells. Abstract : A novel Zn incorporation strategy is developed to deposit a gradient composition ternary Znx Cd1–x S buffer layer. The gradient band configuration is constructed in the CZTSSe/CdS interface through the control of gradient composition, which suppresses interface recombination, resulting more favorable band alignment, and larger V OC . Accordingly, the CZTSSe device of 12.35% is achieved.