高效铜锌锡硫薄膜太阳能电池：由DMSO前驱体溶液到半导体膜材料的化学反应路径研究

铜锌锡硫因为具有理想的吸收太阳光的带隙宽度、使用储量高成本低的原材料、可以从简单金属盐由溶液法直接制备及其快速增长的效率而成为最具应用前景的薄膜太阳能电池材料。目前铜锌锡硫12.6%的效率由肼的溶液中制备，而肼的爆炸性及对环境和人类健康的危害将限制其工业化生产。在非肼溶液法制备铜锌锡硫电池的研究中，二甲亚砜（DMSO）溶液处于领先地位。然而目前对该溶液中的化学反应，由溶液到半导体膜材料的化学反应路径还知之甚少。本项目将通过研究铜、锌、锡的盐与硫脲在DMSO溶液的生成的化合物，并以这些配合物为新的前驱体，探究前驱体溶液影响半导体材料性质的机理，进一步优化溶液组成，更精确地控制成膜工艺，将CZTSSe电池的效率提高到世界领先水平。并通过在溶液中直接加入掺杂剂的方法研究掺杂对铜锌锡硫光电性能的影响，探讨CZTSSe的缺陷态化学，进一步提高对铜锌锡硫半导体材料的认识。

Copper-zinc-tin sulfoselenide (CZTS) is one of the most promising semiconductors for thin film solar cells because it has a direct bandgap ideally suited to the solar spectrum, composed of Earth-abundant elements, high quality thin films can be formed by solution processing and rapid improvement in efficiency. The current best CZTSSe solar cells with the efficiency of 12.6% are made from hydrazine solution processed CZTSSe absorber material. Safety and environmental concerns of this solvent might prevent it from industrial manufacturing. Among a variety of non-hydrazine solutions explored, DMSO solution is the most promising one. However, the solution chemistry of the DMSO precursor solution and the reaction pathways from solution to solid state film remains unknown. This project will investigate the mechanism of how the precursor solution affects the final CZTSSe absorber materials, optimize CZTS molecular ink composition, rationally control film processing condition and fabricate high quality CZTS semiconducting films. This project will also investigate the effect of the dopants to the photovoltaic performance of CZTSSe solar cells by adding the dopants directly to the precursor solutions and study their point defect chemistry which will lead to better understanding of this semiconductor as photovoltaic material.