金属成分对固态硫化CZTS薄膜性能的影响

Effect of the Metallic Compositions on the Properties of the CZTS Thin Films Prepared by Solid-State Sulfurization

采用磁控溅射法制备铜锌锡(CZT)金属预制膜,再利用固态硫化法制备了Cu2ZnSnS4(CZTS)薄膜。研究了CZT金属预制膜中Sn的原子数分数对CZTS薄膜的化学成分、结构组织和光学性能的影响规律。结果表明:实验制备的CZT金属预制膜硫化后均能得到主相为CZTS的薄膜。在适当的范围内增加CZT金属预制膜中Sn的原子数分数可提高CZTS薄膜的结晶度,有利于生长均匀致密的CZTS薄膜;Sn的原子数分数过高时,硫化后制得的CZTS薄膜存在杂相Sn2S3。当CZT预制膜中各成分的原子数分数比为yZn/ySn=0.24,yCu/yZn+Sn=0.33时,固态硫化后可获得表面均匀致密、具单相的CZTS薄膜,该薄膜中yZn/ySn=1.15,yCu/yZn+Sn=0.92,光吸收系数达104 cm-1,光学带隙为1.52 eV。

The Cu-Zn-Sn（CZT）metallic precursors were prepared by the magnetron sputtering method,then the Cu2ZnSnS4（CZTS）thin films were prepared by the solid-state sulfurization method.The effect rules of the atomicity fraction of Sn in the CZT metallic precursors on the chemical composition,structure and optical properties of the CZTS thin films were investigated.The results show that the CZTS thin films can be obtained through the sulfurized CZT metallic precursors prepared by the experiment.The increase of the suitable atomicity fraction of Sn in the CZT metallic precursors can improve the crystallinity of the CZTS thin films and make the CZTS thin films more uniform and compact.The excessive high atomicity fraction of Sn leads to the presence of Sn2S3 phase in sulfurized CZTS thin films.When the atomicity fraction ratios of yZn/ySnand yCu/yZn＋Snin CZT precursors are 0.24 and 0.33 respectively,the sulfurized CZTS thin film is uniform and single phase.The ratios of yZn/ySnand yCu/yZn＋Snare 1.15 and 0.92 respectively,the optical absorption coefficient is 104 cm-1 and optical band gap is 1.52 eV.