Determining the optical properties of Transparent and Conductive Oxides for thin film solar cells

This paper presents a method for determining the complex refractive index of a Transparent and Conductive Oxide that is embedded in a multilayer structure. The procedure assumes that the optical properties of others materials forming the structure are known and only the real and the imaginary part of the refractive index are unknowns. The refractive index is determined by exploiting the matrix model of light propagation along with experimental measurements of the light transmitted through the complete multilayer device. A simple multilayer structure, formed by a ZnO thin film deposited on a thick glass substrate, is analyzed to evidence the reliability of the method. Results show that the by adopting for the ZnO the refractive index extracted with the proposed procedure, a reliable description of light propagation through multiple layers can be obtained.