Abbas Muhammad, Liang Lifeng, Jian Yue, Ishaq Muhammad, Chen Yong, Ahmad Munir, Su Zhenghua, Chen Shuo, Hu Juguang, Liang Guangxing
Institute of Thin Film Physics and Applications, Shenzhen Key Laboratory of Advanced Thin Films and Applications, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, State Key Laboratory of Radio Frequency Heterogeneous Integration, College of Electronics and Information Engineering, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, Guangdong, 518060, China.
Small. 2025 Jul;21(26):e2500947. doi: 10.1002/smll.202500947. Epub 2025 May 6.
Kesterite CuZnSn(S,Se) (CZTSSe)-based photocathodes present promising solutions for solar hydrogen evolution, owing to their non-toxic, cost-effective nature and exceptional photoelectrochemical (PEC) properties. Traditionally, the development of CZTSSe-based photocathodes for PEC water splitting have utilized CdS as the electron transport layer (ETL) owing to its favorable band alignment with the CZTSSe light-absorbing thin film. However, its environmental concerns pose a significant challenge. Therefore, it is crucial to identifying an eco-friendly ETL that ensures effective band alignment with kesterite materials. In this study, the Zn/Sn ratio and the thickness of the (Zn,Sn)O buffer layer is optimized to fabricate a Cd-free CZTSSe/(Zn,Sn)O/TiO₂/Pt photocathode. This design not only promotes environmental safety but also establishes optimal spike-like band alignments with the CZTSSe thin film. The optimized photocathode demonstrates excellent charge carrier separation and transfer, resulting in a photocurrent density of 29.80 mA cm at 0 V and a half-cell solar-to-hydrogen (HC-STH) conversion efficiency of 4.0% in a 0.5 M H₂SO₄ electrolyte. As research continues to optimize the alternative materials, Cd-free CZTSSe/(Zn, Sn)O-based photocathodes along with their eco-friendly nature hold great promise for achieving competitive efficiencies in sustainable solar-to-hydrogen energy applications.
基于硫铜锡锌矿CuZnSn(S,Se)（CZTSSe）的光阴极由于其无毒、成本效益高的特性以及优异的光电化学（PEC）性能，为太阳能制氢提供了有前景的解决方案。传统上，用于PEC水分解的基于CZTSSe的光阴极开发一直使用硫化镉（CdS）作为电子传输层（ETL），因为它与CZTSSe光吸收薄膜具有良好的能带对准。然而，其对环境的影响带来了重大挑战。因此，识别一种能确保与硫铜锡锌矿材料有效能带对准的环保型ETL至关重要。在本研究中，优化了（Zn,Sn）O缓冲层的锌/锡比和厚度，以制备无镉的CZTSSe/（Zn,Sn）O/TiO₂/Pt光阴极。这种设计不仅促进了环境安全，还与CZTSSe薄膜建立了最佳的尖峰状能带对准。优化后的光阴极表现出优异的电荷载流子分离和转移，在0.5 M硫酸电解液中，在0 V时的光电流密度为29.80 mA cm，半电池太阳能制氢（HC-STH）转换效率为4.0%。随着研究不断优化替代材料，基于无镉CZTSSe/（Zn,Sn）O的光阴极及其环保特性在可持续太阳能制氢能源应用中实现具有竞争力的效率方面具有巨大潜力。
