Laser-induced modification in structural, morphological, linear and non-linear optical parameters of Ge20Ag10Te10Se60 thin films for optoelectronic applications

The current study reveals the time dependent laser irradiation induced modifications in structural and optical properties of the thermally evaporated Ge20Ag10Te10Se60 thin films. The amorphous nature of the films is unchanged with irradiation time. The morphological study depicts very small changes in the microstructure of the films. The average particle size is found to be 8.24 nm from transmission electron microscopy for the high irradiated film. The indirect optical bandgap of the films increased while the refractive index decreased with increase in irradiation time. The dispersion parameters decreased along with the decrease in dielectric loss with increase in irradiation time, making the material useful for various electrical applications. The non-linear refractive index (n2) and susceptibilities (chi(1) and chi (3)) are found to be decreased with increased irradiation time. The non-linear absorption coefficient increased with increase in incident energy. The surface wettability study shows the hydrophobicity nature of the films which enables it for application in different coating materials. The observed changes in different optical parameters of the films under laser irradiation makes it eligible for various optoelectronics applications.