Self-stabilizing molecular solution for Cu2SnS3 thin film: An insight into the oxidation inhibitor of bivalent tin ion
Self-stabilizing molecular solution for Cu2SnS3 thin film: An insight into the oxidation inhibitor of bivalent tin ion
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DOI：
10.1016/j.jpowsour.2021.229699
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发表时间：
2021-05
影响因子：
9.2
通讯作者：
M. Yang;Xiao-Juan Huang;L. Yao;Limei Lin;Aicheng Chen;Yongqing Chen;Yuliang Che;Shuiyuan Chen-Shuiyuan-C
中科院分区：
文献类型：
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作者：
M. Yang;Xiao-Juan Huang;L. Yao;Limei Lin;Aicheng Chen;Yongqing Chen;Yuliang Che;Shuiyuan Chen-Shuiyuan-C
金属-硫脲络合物分子溶液法是一种简便有效的Cu_2SnS_3（CTS）薄膜沉积方法。然而，由于柔性金属盐前体，其稳定性仍然具有挑战性。本文报道了一种提高Cu-Sn-S分子溶液稳定性的策略，即利用二价Sn抑制硫脲中S2-的氧化还原反应。系统的实验揭示了自稳定机制，并通过金属-硫脲体系的自发反应过程得到了证实。结果表明，低价态Sn的存在减弱了硫脲向Cu ~（2+）和Sn ~（4+）的孤对电子转移，由于Sn ~（2+）的易还原性，减少了硫脲氧化硫的析出。添加Sn ~（2+）抗氧化剂的溶液可在空气中长期保存，然后用Sn粉补偿进行旋涂和硫化。最终实现了具有成分控制的均匀CTS薄膜，并提供了1.15%的器件效率。这一工作为硫系薄膜沉积中溶液前驱体的稳定化提供了指导。
Molecular solution with the metal-thiourea complex is a facile and effective route for Cu2SnS3(CTS) thin film deposition. However, its stability is still challenging due to flexible metal salts precursors. Here we report a strategy to enhance the stability of the Cu–Sn–S molecular solution that use bivalent Sn to suppress the oxidation of the S2-of thiourea via the redox reaction. The self-stabilizing mechanism has been carefully revealed by the systematic experiments and confirmed by the spontaneous reaction process of metal-thiourea system. It demonstrates that Sn with a low valence state weakens the transfer of lone pair electrons from thiourea to Cu2+and Sn4+ions, alleviating the sulfur precipitates from thiourea oxidation because of the easily reducible character of Sn2+ion. The solution with Sn2+antioxidant additive can be stored for a long time under air ambient, which is then spin-coated and sulfurized with Sn powder compensation. The uniform CTS thin film with composition control is finally achieved and delivers a device efficiency of 1.15%. This work provides a guide on stabilizing the solution precursor for chalcogenide thin film deposition.