Reduction temperature effects on the characteristics of copper-indium-gallium diselenide thin films in sol-gel method

• Main Authors: Wen Jei Li, 李文傑
• Other Authors: M. J. Jeng
• Format: Others
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/89841822170283615411

碩士 === 長庚大學 === 光電工程研究所 === 100 === The reduction temperature influence on the characteristics of CIGS thin films prepared by sol-gel method is investigated. Five different reduction temperatures of 250, 280, 350, 380 and 450 oC are studied in this thesis. The EDS results indicate that the copper content in the precursor increases with the increasing reduction temperature. The XRD spectra exhibit that the precursor shows an amorphous structure when the reduction temperature is lower than the temperature of 280 oC and begins to form a crystalline structure of In2O3 phase when the reduction temperature is higher than the temperature of 350oC. After the selenization, both of the grain size and copper content in CIGS thin films increase with the increasing reduction temperature. In addition, there exist many large grain sizes of Cu-Se compounds on the surface of CIGS thin films when the ratio of copper to indium and gallium is higher than the value of 0.9. The forming In2O3 phase in the precursor cannot be removed after selenization processing when the reduction temperature is higher than 350 oC. From Raman measurements, it was also observed that the In2O3 phase existed in the CIGS thin films. It is noted that the gel cannot be removed completely when the reduction temperature is lower than 250 oC. Thus, it is suggested that the reduction temperature should be in the range of 250 to 280 oC to obtain a good quality of CIGS thin films.