Broadening the processing window is of high importance for developing efficient Cu₂ZnSn(S,Se)₄ (CZTSSe) solar cells. Herein, a high efficiency (active-area: 13.5%) of CZTSSe solar cells achieved from thioglycolic acid (TGA)-ammonia based water solution method is first reported. The cell performance exhibits the high tolerance to the element composition variations of the CZTSSe film. Film crystallization and chemical mechanism studies reveal that this high composition-tolerance mainly benefits from an existence of a conductive carbon framework layer with high element accommodating ability and a phase-segregation growth behavior of CZTSSe grains driven by thermodynamics properties of the heterogeneous film system. It is shown that Sn–TGA coordination capable to induce large metal–organic molecule clusters plays a critical role in forming the mesoscopic carbon layer. These results and related material mechanism provide new routes to regulate crystal growth of the CZTSSe film for further improving cell performance.

中文翻译：

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高效且成分耐受的黄铜矿 Cu2ZnSn(S, Se)4 太阳能电池源自原位形成的多功能碳框架

拓宽加工窗口对于开发高效的 Cu ₂ ZnSn(S,Se) _{4 非常重要}(CZTSSe) 太阳能电池。在此，首次报道了通过巯基乙酸（TGA）-氨水溶液法获得的高效率（活性面积：13.5%）的 CZTSSe 太阳能电池。电池性能表现出对 CZTSSe 膜元素组成变化的高耐受性。薄膜结晶和化学机理研究表明，这种高成分耐受性主要得益于具有高元素容纳能力的导电碳骨架层的存在以及由异质薄膜系统的热力学特性驱动的 CZTSSe 晶粒的相分离生长行为。结果表明，能够诱导大金属有机分子簇的 Sn-TGA 配位在形成介观碳层中起着关键作用。