溅射Cu-Zn-Sn金属预制层后硫(硒)化法制备Cu2ZnSn(SxSe1-x)4薄膜及其光伏特性

采用溅射工艺制备Cu-Zn-Sn金属预制层并尝试在多种退火方案(硫化退火、硒化退火、不同温度下硫化后硒化)下对其进行退火处理,探索出一种只需采用金属预制层即可完成CZTSSe制备的退火工艺制度.通过扫描电镜对比研究了不同退火制度下Cu2ZnSn(SxSe1-x)4薄膜的形貌差异,发现低温硫化后硒化工艺可以有效减少因硫化温度过高引起的薄膜中孔洞较多的问题,有利于薄膜的平整与致密化.在此基础上,采用 X射线荧光光谱、扫描电镜、X 射线衍射及拉曼光谱对不同硫化温度(200 ℃、300℃、400 ℃、500 ℃)下硫化后硒化工艺制备的Cu2ZnSn(SxSe1-x)4薄膜的成分、形貌、物相结构及结晶性能进行了表征和分析.结果表明,300 ℃下硫化后硒化获得的Cu2ZnSn(SxSe1-x)4较其他温度下硫化后硒化获得的产物有着更好的形貌及结晶性能,其器件的光电转换效率为2.09%,远高于500 ℃下硫化后硒化工艺所得薄膜器件的效率(0.94%).

Photovoltaic Characteristics of Cu2ZnSn(SxSe1-x)4Thin Films Synthesized via the Process of Cu-Zn-Sn Presputtering and Subsequent Sulfurization (Selenization)Annealing

By applying several annealing schemes (sulfurization,selenization,sulfurization at various temperatures→seleniza-tion)to the annealing process of the magnetron sputtered Cu-Zn-Sn coating,this work made a successful attempt to develop an an-nealing scheme that enables the production of CZTSSe thin film on the basis of merely a presputtered metallic coating.We conducted the morphological analyses upon the Cu2ZnSn(SxSe1-x)4films formed through different annealing schemes and revealed that a rela-tively low sulfurization temperatures can benefit the flatness and densification of the resultant film by attenuating the heat-induced po-rosification effect.A comparative study was then carried out upon the effect of the sulfurization temperature (200 ℃,300 ℃,400℃,500 ℃)on the properties of Cu2ZnSn(SxSe1-x)4thin films,by measuring the films'composition,morphology,structure and crystallinity via XRF,SEM,XRD and Raman scattering.Among the above competitors,the Cu2ZnSn(SxSe1-x)4film obtained with 300 ℃ sulfurization→selenization exhibits the most favorable morphology and crystallinity,as well as a power conversion efficiency of 2.09% which far outperforms the one with 500 ℃ sulfurization→selenization (0.94%)owing to the boost of short-circuit current and fill factor.