High-efficiency CIGS submodules

Abstract

The approaches and achievements in the development of high-efficiency CuInGaSe2 (CIGS) monolithically integrated submodules will be reported. Two types of techniques, the conventional (batch-process) and the in-line three-stage evaporation techniques, have been employed to deposit high-quality CIGS absorbers on 10 × 10-cm Mo/soda lime glass substrates. CIGS films deposited by both the conventional and the in-line evaporation techniques showed an in-depth compositional grading of In and Ga (referred as the double graded bandgap) which is a fingerprint of the three-stage evaporation process. The optimization of the integration processes such as mechanical scribing, as well as the improvement in electrical and optical properties of ZnO window layers, made possible the demonstration of high-efficency CIGS submodules with efficiencies as high as η = 16.6% (aperture area: 67.2 cm2) and η = 15.8% (aperture area: 76.5 cm 2) for the conventional and the in-line evaporation process, respectively. Copyright © 2012 John Wiley & Sons, Ltd.