Abstract It is theoretically and experimentally challenging to fabricate single phase Cu2ZnSnS4 (CZTS) and more difficult to synthesize it by sol–gel method. Theoretical work reveals that Na can passivate the dangling bonds in the grain boundaries of CZTS and thus enhance the photovoltaic performance. Therefore, Na incorporation may be an effective way in passivating defects in CZTS films and fabricating CZTS with high quality and single phase. In this study, we will try to incorporate Na into CZTS films by sol–gel method to help passivate defects in CZTS and achieve single phase kesterite CZTS films using a different solvent 2-methoxybutanol. Different Na/(Cu + Zn + Sn) atomic ratios (0%-3%) will be employed. Through controlling Na incorporation amount in solution, we can prevent the generation of other phases like SnO2 and a pure single phase kesterite CZTS can be achieved. The optical band gap of the optimal CZTS film is 1.24 eV. All Na doped CZTS films show p-type conduction behavior.

中文翻译：

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Na掺入控制的单相黄铜矿Cu2ZnSnS4太阳能电池材料

摘要 制备单相 Cu2ZnSnS4（CZTS）在理论上和实验上都具有挑战性，而通过溶胶-凝胶法合成则更加困难。理论工作表明，Na 可以钝化 CZTS 晶界中的悬空键，从而提高光伏性能。因此，Na 掺入可能是钝化 CZTS 薄膜缺陷和制备高质量单相 CZTS 的有效方法。在这项研究中，我们将尝试通过溶胶-凝胶法将 Na 掺入 CZTS 薄膜中，以帮助钝化 CZTS 中的缺陷，并使用不同的溶剂 2-甲氧基丁醇实现单相锌黄铜矿 CZTS 薄膜。将采用不同的 Na/(Cu + Zn + Sn) 原子比 (0%-3%)。通过控制溶液中Na的掺入量，我们可以防止其他相如 SnO2 的生成，并且可以实现纯单相锌黄锡矿 CZTS。最佳 CZTS 薄膜的光学带隙为 1.24 eV。所有 Na 掺杂的 CZTS 薄膜都表现出 p 型导电行为。