Study of Structural and Optical Properties of Cu2ZnSnS4 and Cu2ZnGeS4 Thin Films Synthesized by Sulfurization of Stacked Metallic Layers

• Published in: Materials science forum Vol. 814; pp. 44 - 48
• Main Authors: He, Jun, Chen, Lei Lei, Chu, Jun Hao, Huang, Ling, Deng, Hong Mei, Yang, Ping Xiong
• Format: Journal Article
• Language: English
• Published: Pfaffikon Trans Tech Publications Ltd 01.03.2015
• Subjects: Copper; Efficiency; Materials science; Optical properties; Semiconductors; Spectrum analysis; Thin films; China; Solar Energy Materials; Cu2ZnGeS4 Thin Film; Sulfurization; Cu2ZnSnS4 Thin Film; Sputtering
• ISSN: 0255-5476; 1662-9752; 1662-9752
• DOI: 10.4028/www.scientific.net/MSF.814.44

Cu2ZnSnS4 and Cu2ZnGeS4 thin films made from the earth abundant and non-toxic materials are quaternary semiconducting compounds which have received increasing interest for solar cells applications. Cu2ZnSnS4 and Cu2ZnGeS4 thin films have been synthesized by sulfurization of radio frequency magnetron sputtered precursors. The structural and optical properties of the thin films have been investigated and discussed. The result of X-ray diffraction demonstrates that the Cu2ZnSnS4 and Cu2ZnGeS4 thin films have kesterite (KS; space group I) crystal structure. An obvious blue shift is observed in the Raman spectra as smaller Ge replaces Sn. It is due to the fact that the radius of Ge cation is smaller than that of Sn cation , which results in the shrink of the lattice. Further transmission spectra demonstrate that the values of band gap for CZTS and CZGS thin films are 1.54 eV and 1.98 eV, respectively.