Effect of Gamma- Irradiation on the Optical Properties of HDPE/GaAs Composite Films

This work presents a systematic investigation of the effect of gamma irradiation on the optical properties and band gap characteristics of high-density polyethylene (HDPE) polymer and HDPE/GaAs composite films irradiated at absorbed doses of Φγ = 100, 200, and 300 kGy at room temperature.The optical absorption coefficient was determined from UV-Visible spectra, and the dependences of (αhν) 2 and (αhν) 1 2 on photon energy were analyzed for pristine and irradiated samples.The optical absorption edge parameters associated with direct-and indirect-type electronic transitions were evaluated using the Mott-Davis approach, and their dose-dependent evolution was established.A comparative analysis reveals a linear decrease of the optical gap parameters with increasing irradiation dose for both polymer and composite films.Notably, the slope of the dose dependence associated with indirect-type transitions exhibits a pronounced sensitivity to gamma irradiation, indicating the dominant role of radiation-induced localized states and interfacial disorder in governing optical absorption.The results demonstrate that controlled gamma irradiation provides an effective route for tuning the optical response of polymer-semiconductor composite systems intended for radiation-resistant optoelectronic applications.