suggest that form Cu2Sn form as an intermediate phase on the way to forming CzTS because Cu and Sn have a strong tendency to form alloys during the deposition of the metal stack.These alloys are sulfidized first to form Cuzsns, and then eventually convert to CZTS at above 500 °C. Moreover, Sn losses through desorption of sns(e) from CzTs(e) and the formation of ternary semiconductors Cu2sns(e), at elevated temperatures have been observed in many cases, which would impede the thorough control of film composition and film homogeneity.