Process and RTP equipment design for Cu(In, Ga)Se2 layer formation using in-situ XRD techniques

Centrotherm photovoltaics AG is one of the first turn-key supplier of fabrication lines for the production of whole Cu(In, Ga)Se₂ (CIGSe)-based thin-film modules of a size of ~1.5m². A novel atmospheric pressure Se deposition process in combination with an atmospheric through-type furnace offers a very fast approach for CIGSe manufacturing [1]. Centrotherm Photovoltaics AG has set up, a unique laboratory-scale in-situ X-Ray diffraction (XRD) system allowing for the real-time investigation of the relevant phase formation processes [2]. This device is build around a small rapid thermal processing (RTP) furnace, mapping centrotherms large furnace atmospheric CIGSe-formation process to a laboratory scale. In this paper we will report on the systematic progress made in CIGSe RTP process design using this unique laboratory tool. The combined analysis of the phase evolution by insitu-XRD (i-XRD) and morphological studies (SEM) at defined reaction stages and corresponding EXD mappings leads to a concise understanding of the reaction process.