Fabrication process and device application of chalcopyrite phosphides based on thermodynamics

Abstract

In this article, we introduce our studies on application of chalcopyrite phosphides to solar cells, such as bulk crystal growth based on phase diagram, and thin film deposition based on chemical potential diagram. As well known, phase diagram is a useful tool for fabrication of multicomponent materials, while chemical potential diagram, which is a kind of phase diagram with chemical potentials as axes, is well adaptable with vapor growth. The difference of deposition mechanism between ZnSnP₂ and CdSnP₂ thin films is well explained. We also introduce a discussion on the stability of hetero-interface through chemical potential diagrams, and bandgap control via order-disorder phenomena. Especially, we demonstrated the bandgap of ZnSnP₂ is controlled from 1.2 to 1.7 eV without composition change.