SCALABILITY AND PILOT OPERATION IN SOLAR-CELLS OF CUINSE2 AND THEIR ALLOYS

The compound Cu(Ga,In)Se-2 (CIGS), and related compounds, have demonst rated their high potential for high-efficiency thin-film solar cells u p to levels approaching 18%, It is expected that this quality can be f urther improved by optimizing process conditions and combining the CIG S with other group I, III and VI elements. Other material combinations are render development, Several companies and research institutes are developing CIGS-based technology with the aim of low cost/high volume production, The key process is a scalable technology to fabricate hig hest quality CIGS films on a large area with high throughput and proce ss yield. The Centre for Solar Energy and Hydrogen Research (ZSW) and the University of Stuttgart (IPE) are working together on CIS technolo gy. On the module basis ZSW is negotiating with private companies to c ommercialize module technology. These activities are compared with oth ers worldwide, With the aim of developing relevant high-volume fabrica tion technologies, all laboratory deposition techniques that have pl o ven highest device performance are applied also on the module level to prevent physical and chemical effects that could limit device perform ance, All film deposition techniques are developed for high-vacuum in- line fabrication on a large area except for the buffer layer of CdS, a nd monolithic integration is realized by patterning steps, Modules are prepared on substrate areas of 10 x 10 up to 30 x 30 cm(2). Actual re sults of modules of these sizes are 14% and 10%, respectively. Estimat ions of fabrication costs with increasing fabrication volume show that if is possible to produce CIGS modules at costs wed below US$1 W-p(-1 ). (C) 1998 John Wiley & Sells, Ltd.