Chemical etching of Cu(In,Ga)Se2 layers for fabrication of electronic devices

Cu(In,Ga)Se2 thin films have been grown by electrodeposition. The layers, having thicknesses of a few micrometers, have been exposed to various commonly used wet chemical etchants. The effect on surface composition and chemistry has been studied using X-ray photoelectron spectroscopy. The results indicate that the choice of etchant has a dramatic influence on both surface composition and chemistry. These etchants can result in strong selective dissolution of one of the constituent elements to such an extent that the element can be almost entirely removed from the surface layer. The possible effects on electronic device performance are discussed.