CIGS absorbers and processes

The current status and future perspectives of Cu(In1-xGax)Se-2 (CIGS) solar cells and modules will be discussed in this paper. The conversion efficiencies of the state of the art laboratory-scale CIGS solar cells exceeded 20%, which are comparable to those of crystalline Si solar cells. The requirements on the properties of CIGS absorbers to achieve such high efficiencies will be described. The CIGS modules are already commercially available based on two major CIGS deposition techniques such as co-evaporation and selenization. The current status, problems, and prospects of co-evaporation and selenization will also be discussed. High-efficiency flexible CIGS solar cells with efficiencies similar to those fabricated on soda-lime glass (SLG) substrates have been achieved by developing a novel Na incorporation technique. Critical issues to demonstrate high-efficiency flexible solar cells will also be discussed. Copyright (C) 2010 John Wiley & Sons, Ltd.