The effect of coloration on optical properties of molybdenum trioxide thin films prepared by thermal evaporation technique

Thin films of molybdenum trioxide (MoO
₃
) were deposited onto a glass substrate by thermal evaporation technique. The nanostructure of the deposited films was controlled by heat treatment. The effect of UV irradiation on samples were systematically studied. This UV irradiation has been found as effective way for colouring the samples, and a correlation was established between, microstructure and UV irradiation. The optical properties of the MoO
₃
films were studied by calculating the index of refraction and the extinction coefficient. A strong dependence of the coloration on the optical constants and optical properties of the MoO
₃
thin films was obtained.