YIELD ISSUES ON THE FABRICATION OF 30 CM X 30 CM-SIZED Cu(In,Ga)Se2-BASED THIN-FILM MODULES

• Published in: Solar energy materials and solar cells 2003-01, Vol.75 (1-2), p.171-178
• Main Authors: Kushiya, K, Ohshita, M, Hara, I, Tanaka, Y, Sang, B, Nagoya, Y, Tachiyuki, M
• Format: Article
• Language: English
• ISSN: 0927-0248
• DOI: 10.1016/S0927-0248(02)00144-7

The approaches to establish a more robust and reproducible baseline process for 30 cm x 30 cm-sized CIGS-based thin-film circuits with a Zn(O,S,OH)x buffer layer are reported, which also lead to an achievement of 12.93% efficiency on an aperture area of 864 cm2. Monitoring the transparency or transmittance (%T) of dip solution as a process control parameter in the chemical bath deposition (CBD)-buffer deposition step and setting the end point of dipping the CIGS-based absorbers in the solution as the %T of 60% contribute to make CBD-buffer deposition process more reproducible. By considering the growth process of MOCVD-ZnO:B window, a thin layer of high-resistivity, intrinsic ZnO is deposited on the Zn(O,S,OH)x buffer layer to simulate the film structure of MOCVD-ZnO:B window in the case of sputtered-5.7 GZO window. Achievement of the reproducibility of 85% for the CIGS-based thin-film circuits with a sputtered-5.7 GZO window confirms that the yield goal of 85% is surely attainable independent of window-layer deposition techniques, such as MOCVD and sputtering. It is emphasized how important to eliminate unknown factors in the fabrication process for CIGS-based thin-film modules to improve both reproducibility and efficiency. 4 refs.