Advanced Physical Research

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<Te> composite films irradiated at absorbed doses of Φ_γ = 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)¹ᐟ² 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.