Highest Solar-to-Hydrogen Conversion Efficiency in Cu2ZnSnS4 Photocathodes and Its Directly Unbiased Solar Seawater Splitting

作者：Muhammad Abbas, Shuo Chen, Zhidong Li, Muhammad Ishaq, Zhuanghao Zheng, Juguang Hu, Zhenghua Su, Yanbo Li, Liming Ding, Guangxing Liang · 发表于：Nano-Micro Letters · 年份：2025 · DOI：10.1007/s40820-025-01755-8 · 被引用次数：44 · 研究领域：Chalcogenide Semiconductor Thin Films、Quantum Dots Synthesis And Properties、Copper-based nanomaterials and applications

Abstract Despite being an excellent candidate for a photocathode, Cu 2 ZnSnS 4 (CZTS) performance is limited by suboptimal bulk and interfacial charge carrier dynamics. In this work, we introduce a facile and versatile CZTS precursor seed layer engineering technique, which significantly enhances crystal growth and mitigates detrimental defects in the post-sulfurized CZTS light-absorbing films. This effective optimization of defects and charge carrier dynamics results in a highly efficient CZTS/CdS/TiO 2 /Pt thin-film photocathode, achieving a record half-cell solar-to-hydrogen (HC-STH) conversion efficiency of 9.91%. Additionally, the photocathode exhibits a highest photocurrent density ( J ph ) of 29.44 mA cm −2 (at 0 V RHE ) and favorable onset potential ( V on ) of 0.73 V RHE . Furthermore, our CTZS photocathode demonstrates a remarkable J ph of 16.54 mA cm −2 and HC-STH efficiency of 2.56% in natural seawater, followed by an impressive unbiased STH efficiency of 2.20% in a CZTS-BiVO 4 tandem cell. The scalability of this approach is underscored by the successful fabrication of a 4 × 4 cm 2 module, highlighting its significant potential for practical, unbiased in situ solar seawater splitting applications.