Nanocomposites (NC) of amorphous polycarbonate (PC) and cerium oxide (CeO2) nanoparticles (NPs) were prepared. The synthesized CeO2 had a nanonature of average particle size 22 nm, as indicated from their high resolution transmission electron microscopy images (HTEM). Samples of the PC/CeO2 NC films were irradiated with several γ ray doses (10-80 kGy). The resultant outcome of the γ irradiation on the optical properties of the NC films was studied using ultraviolet spectroscopy (UV-vis). Upon raising the γ ray dose up to 80 kGy, the maximum dose used, the direct bandgap decreased from 4.92 to 3.91 eV. The Urbach energy showed an opposite trend; it increased from 0.46 to 0.92 eV. This could be attributed to the domination of chain crosslinks. Also, the optical dielectric loss (ε”) assisted in identifying the nature of the microelectronic transitions. It was found that the PC/CeO2 NC films had direct allowed transitions. Additionally, the γ induced changes in the optical conductivity were studied. Moreover, the optical color changes between the pristine and the irradiated films were evaluated. The pristine NC film was uncolored. It showed significant color changes when irradiated with γ radiation up to 80 kGy. The induced modifications in the optical properties suggest that the γ radiation is an effective means for modifying the properties that allows the use of PC/CeO2 NC in optoelectronic devices.
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