Analysis of untreated cross sections of Cu(In,Ga)Se2 thin-film solar cells with varying Ga content using Kelvin probe force microscopy

Abstract

The potential distribution of the Cu(In,Ga)Se2/CdS/ZnO layer structure on untreated cross sections of Cu(In,Ga)Se2 thin-film solar cells are analyzed by Kelvin probe force microscopy under ambient conditions. The potential differences between the Cu(In,Ga)Se2 absorber and the ZnO window layer are systematically investigated, providing direct evidence for a Fermi energy shifting in Cu(In,Ga)Se2 absorbers with different Ga content. © 2011 American Institute of Physics.