Formation of ZnS particles in the Cu₂ZnSnS₄ (CZTS) light absorber layer of CZTS solar cells may impede the photocarrier collection as well as the open circuit voltage. Coevaporation of Cu, Zn, Sn, and S elements can provide a uniform and well‐mixed Cu–Zn–Sn–S precursor at atomic level, yet the annealing/sulfurization process does not preserve such elemental distribution. The Zn element in the formed CZTS absorber thin films from such a uniform precursor distributes unevenly, especially aggregating near the rear interface, and thus deteriorates the film quality. Herein, the movement pathway of the Zn element in the coevaporated precursor during annealing is investigated through energy dispersive X‐ray spectroscopy (EDX) mapping and secondary ion mass spectroscopy (SIMS) profiling. With the understanding of the segregation behavior of the Zn element, an active manipulation of the initial distribution of Zn in the precursor is accordingly designed to effectively alleviate the accumulation of Zn near the rear Mo/CZTS interface and therefore improve the crystalline quality of the absorber. The results suggest that properly controlling the precursor.

中文翻译：

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ZnS颗粒在Cu2ZnSnS4薄膜太阳能电池性能中的作用：通过共蒸发前驱体中锌沉积的主动控制进行的比较研究

在Cu ₂ ZnSnS _4中形成ZnS颗粒CZTS太阳能电池的（CZTS）光吸收层可能会阻止光载流子的收集以及开路电压。Cu，Zn，Sn和S元素的共蒸发可以在原子水平上提供均匀且充分混合的Cu-Zn-Sn-S前体，但是退火/硫化过程不能保留这种元素分布。由这种均匀的前体形成的CZTS吸收体薄膜中的Zn元素不均匀地分布，特别是在后界面附近聚集，从而使膜质量劣化。本文中，通过能量色散X射线能谱（EDX）映射和二次离子质谱（SIMS）谱图研究了退火过程中共蒸发前体中Zn元素的移动路径。了解了Zn元素的偏析行为后，因此，设计了对前驱体中Zn初始分布的主动控制，以有效减轻Zn在Mo / CZTS后界面附近的积累，从而提高吸收剂的结晶质量。结果表明适当控制了前体。