Spectroscopic ellipsometry investigation of optical and interface properties of CdTe films deposited on metal foils

Optical and interface properties of the CdTe films electrodeposited on Molybdenum and Stainless Steel substrates were investigated using variable angle spectroscopic ellipsometer measurement and multilayer optical analysis. The refractive index of CdTe film obtained from the multilayer optical modeling is found to be lower than single crystal data. The Bruggeman effective medium analysis shows that the films consist of nearly 11% void due to poor crystallinity resulting in the lower refractive index. The multilayer optical model also indicates the presence of a Te rich interface between CdTe and substrate, which can be associated to the kinetics of CdTe electrodeposition that starts from nucleating Te on substrate surface followed by the formation of CdTe.