Back-contact modification using a 10-nm ZnS layer in CZTSSe-based solar cell can play a crucial role in improving photovoltaic conversion efficiency. An ultrathin layer of ZnS is deposited over Mo-coated soda lime glass substrate before depositing CZTSSe using sputtering. The crystal structure of deposited CZTSSe thin films over ZnS is recognized as (112)-oriented, polycrystalline in nature, and free from the presence of any secondary phases such as Cu 2 (S,Se) or Zn(S,Se). The bandgap of CZTSSe thin films deposited over ultrathin ZnS is observed to increase from 1.49 (deposited over Mo directly) to 1.58 eV at room temperature, as determined by spectroscopic ellipsometry. In addition, numerical simulation has been performed using SCAPS software. The impact of ZnS layer has been simulated by using the defects in the absorber and at the interface of ZnS/CZTSSe. The simulated results have been validated with experimentally fabricated CZTSSe device. Simulated device with ZnS intermediate layer is observed to give rise to a photovoltaic conversion efficiency of 15.2%.

中文翻译：

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通过背接触改性提高 Cu2ZnSn(S,Se)4 基光伏转换效率


在CZTSSe基太阳能电池中使用10纳米ZnS层进行背接触改性可以在提高光伏转换效率方面发挥至关重要的作用。在使用溅射沉积 CZTSSe 之前，在镀 Mo 的钠钙玻璃基板上沉积超薄的 ZnS 层。 ZnS 上沉积的 CZTSSe 薄膜的晶体结构被认为是 (112) 取向的多晶性质，并且不存在任何第二相，例如 Cu 2 (S,Se) 或 Zn(S,Se)。通过椭圆偏振光谱法测定，室温下沉积在超薄 ZnS 上的 CZTSSe 薄膜的带隙从 1.49（直接沉积在 Mo 上）增加到 1.58 eV。此外，还利用SCAPS软件进行了数值模拟。利用吸收体和 ZnS/CZTSSe 界面处的缺陷模拟了 ZnS 层的影响。模拟结果已通过实验制造的 CZTSSe 器件得到验证。观察到具有 ZnS 中间层的模拟器件的光伏转换效率为 15.2%。