Contribution of 80 MeV silicon swift heavy ion irradiation for reforming of optical and structural properties of amorphous Ge23Se62As15 thin films for telecommunication and sensing applications

Abstract

Linear and non-linear optical properties are investigated for amorphous Ge23Se62As15 thin films irradiated under 80 MeV Silicon swift heavy ions. The changes in optical properties are understood in terms of glass network structure and parameters of incident ion. Besides, the study verifies the relation between the mean coordination number of glass network and electronic energy loss of the ion. The Swanepoel method and semi-empirical relations are used to determine the optical parameters. The study indicates that the most useful fluence to optimize optical properties is around 3 × 1012 ions/cm2. The amorphous phase of thin film samples is retained till the highest fluence (1 × 1013 ions/cm2) as confirmed using XRD measurements. A highly roughed surface is found at fluence 1 × 1013 ions/cm2 (SEM image observation). The micro Raman study reveals that Ge-Ge, Se-Se bonds, and GeSe4/2 tetrahedral corner-shared structural units are responsible for optical properties modification. Modification in surface morphology and optical/structural properties with the glass network structure and ion treatment parameters is useful for telecom and sensing applications.