Abstract A facile and effective sulfurization method is developed to grow the large-grained Cu2ZnSnS4 (CZTS) films. This method involves short duration of high temperature and adding SnS powder. The roles of SnS powder to promote the growth of CZTS large grains are comprehensively investigated. SnS can suppress the loss of Sn in CZTS precursor during the sulfurization process. More importantly, the reaction between SnS and S leads to the formation of SnS2 intermediate phase, which is a fluxing agent under high S atmosphere and more easily reacts with other secondary phases. Consequently, large grains of CZTS through the whole film thickness are successfully prepared with the help of SnS2. Furthermore, the CZTS solar cell with efficiency of 5.8% (active area efficiency 6.4%) without MgF2 anti-reflection coating is fabricated. The severe carrier recombination within the heterojunction interface is the major factor limiting device efficiency. The optimization for the heterojunction interface is expected to further improve efficiency.

中文翻译：

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生长大晶粒Cu2ZnSnS4薄膜的改性硫化工艺机制

摘要 开发了一种简便有效的硫化方法来生长大晶粒 Cu2ZnSnS4 (CZTS) 薄膜。该方法涉及高温持续时间短和添加 SnS 粉末。全面研究了 SnS 粉末促进 CZTS 大晶粒生长的作用。SnS 可以抑制硫化过程中 CZTS 前驱体中 Sn 的损失。更重要的是，SnS 和 S 之间的反应导致形成 SnS2 中间相，它是高 S 气氛下的助熔剂，更容易与其他第二相反应。因此，在 SnS2 的帮助下，成功制备了贯穿整个薄膜厚度的大颗粒 CZTS。此外，还制备了效率为 5.8%（有效面积效率为 6.4%）的 CZTS 太阳能电池，没有 MgF2 抗反射涂层。异质结界面内严重的载流子复合是限制器件效率的主要因素。异质结界面的优化有望进一步提高效率。