Abstract Thin film of Cu2SnS3 (CTS), a truly inexpensive photovoltaic absorber is deposited by low cost and non-vacuum spray pyrolysis technique on glass substrates. As deposited CTS films are of p-type in nature, however they are characterised with undesirably high free carrier concentration which leads to a large amount of recombination. Such a high carrier concentration is successfully reduced from 1020 cm−3 to the order of 1018 cm−3 by varying the initial molar copper concentration in the precursor solution. A combined XRD and Raman spectroscopy analysis reveals that the coexistence of secondary Cu3SnS4 phase is responsible for the higher carrier concentration of the order of 1021 cm−3, due to its semi-metallic nature. The optical study of the film also shows the reduction in the band gap from 1.73 eV to 1.29 eV with the absorption coefficient of >104 cm-1. These features of the precursor optimised CTS film enable it as a promising photovoltaic absorber.

中文翻译：

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通过改变光伏应用中的铜前体浓度对喷雾热解 Cu2SnS3 薄膜的电性能进行调节

摘要 Cu2SnS3 (CTS) 薄膜是一种真正廉价的光伏吸收体，通过低成本和非真空喷雾热解技术沉积在玻璃基板上。由于沉积的 CTS 薄膜本质上是 p 型的，然而它们的特征是不希望的高自由载流子浓度，这导致大量的复合。通过改变前体溶液中的初始摩尔铜浓度，如此高的载流子浓度成功地从 1020 cm-3 降低到 1018 cm-3 的数量级。结合 XRD 和拉曼光谱分析表明，由于其半金属性质，二次 Cu3SnS4 相的共存是导致 1021 cm-3 数量级的较高载流子浓度的原因。薄膜的光学研究还显示带隙从 1.73 eV 减小到 1。29 eV，吸收系数 >104 cm-1。前体优化的 CTS 薄膜的这些特性使其成为一种有前途的光伏吸收剂。