Determination of interference-free optical constants of thin films

Abstract

A computational procedure has been developed for the accurate determination of interference-free optical constants (refractive index, n 1 and extinction coefficient, k 1) of thin solid films from reflectance ( R) and transmittance ( T) measurements. By using (1− R)/ T function and a successive refinement loop, error in calculation of the absorption coefficient ( α) has been minimized. The method has been successfully used for the determination of optical constants and band gap of CuIn 1− x Ga x Se 2 and Sb 2S 3 thin films.