Cu2ZnSnS4光电功能材料湿法微结构可控沉积及其性能基础研究

Coprecipitation of copper zinc tin sulfid CZTS(Cu2ZnSnS4) photovoltaic material is presented in this project, which aims at solving the problems in traditional vacuum process of CZTS(Cu2ZnSnS4) photovoltaic material such as the difficulty in generation of secondary phases, poor morphology and high cost. Efforts will be devoted to revealing the thermodynamic conditions of coprecipitation of copper zinc tin oxide particles based on the theory analysis of phase diagram of metal-water system. Besides, relevant parameters of coprecipitation will be explored on composition of the copper zinc tin oxide particles, structure of organization,microstructure and evolving law research on the growth mechanism of copper zinc tin oxide particles,then the generation process of oxide particles will be in fine regulation. Furthermore, the influence of microstructure of copper zinc tin oxide particles on the growth mechanism of CZTS thin flim is investigated to determine the best microstructure characteristics of particles .Concurrently, the influence of sulfide annealing treatment process parameters on the powder phase change is investigated. Finally, the optimized parameters of method and system of sulfide annealing will be determined. Revealing CZTS thin film growth of mechanism and defect formation law, the relationship between thin film optical, electrical properties and photovoltaic properties can be established to obtian more than 5% of photoelectric conversion efficiency of small area of solar cell device. Consequently, the project is of great significance in promoting technology of copper zinc tin sulfur (CZTS) photovoltaic material, and further motivating the low-cost production and large scale application of CZTS thin film solar cells.

本项目提出采用共沉淀法制备铜锌锡硫CZTS(Cu2ZnSnS4)光伏材料，以解决传统真空法制备过程中存在的二次相易生成、形貌差和成本高等不足。项目将结合金属水系相图理论分析，揭示共沉淀法制备铜锌锡氧化物颗粒的热力学适宜条件；考查共沉淀工艺参数对铜锌锡氧化物颗粒成分、组织结构和微观形貌的影响，归纳颗粒的形成与生长机制，进而对铜锌锡氧化物的生成过程进行精细调控。研究铜锌锡氧化物颗粒微结构对后续CZTS薄膜生长机制的影响规律，确定最佳的颗粒微结构特性；考察CZTS薄膜退火工艺参数对粉体物相变化的影响，确定优化的退火方式与退火制度。揭示CZTS薄膜的生长机理和缺陷形成规律，建立薄膜光学、电学性能与太阳电池光伏特性之间的关系，获得光电转换效率超过5%的小面积太阳电池器件。本项目的开展可有效促进铜锌锡硫(CZTS)光伏材料制备技术的进步，推动CZTS薄膜太阳电池的低成本制造和规模应用。

CZTS（Cu2ZnSnS4）薄膜材料是一种较理想的光电转换材料，具有直接带隙1.5eV与太阳匹配性好、光吸收系数高（104cm-1）、原料地壳储量大和环境友好等优良特性。但传统制备过程中存在的二次相易生成、形貌差和成本高等不足，为解决此问题，本项目通过共沉淀-煅烧-纳米墨水涂覆-硫化/硒化退火制备性能良好的CZTS/CZTSSe薄膜，并通过器件表征获得了4.11%的光电转换效率。通过精细调控相关参数如pH、温度和PVP含量对铜-锌-锡复合氧化物颗粒成分和尺寸的影响，实现了过程的精确控制；研究了铜锌锡氧化物颗粒微结构对后续薄膜生长机制的影响规律，确定了最佳的颗粒微结构特性，实现了制备CZTS材料的掺杂和改性。考察了CZTS薄膜硫化/硒化退火工艺参数对粉体物相变化的影响，确定了优化的硫化/硒化退火制度。揭示了薄膜的生长机理和缺陷形成规律，建立了薄膜光学、电学性能与太阳电池光伏特性之间的关系。本项目的开展取得了一定意义的工作成果，实现了一种在开放水溶液体系中制备CZTS/CZTSSe薄膜的方法，有望促进铜锌锡硫(CZTS)光伏材料制备技术的进步，推动CZTS薄膜太阳电池的低成本应用。