Ion-irradiation-induced ultraviolet color centers in polydimethylsiloxane

In this study, we examine the evolution of ion-irradiated UV color centers in polydimethylsiloxane (PDMS) at elevated temperatures using UV-Vis spectroscopy. The UV-Vis analysis of ion-irradiated PDMS reveals a distinct absorption peak at 220 nm, attributed to UV color centers. The peak intensity increases with increasing ion dose but gradually decreases during annealing at a given temperature. The characteristic wavelength of the UV color centers remains unchanged, regardless of ion dose and ion source. We propose that the evolution of the absorption peak follows first-order annihilation kinetics, with its intensity directly proportional to the concentration of the UV color centers. The temperature dependence of the rate constants follows the Arrhenius relation, and the activation energy increases with increasing ion dose. The temperature dependence of the equilibrium concentrations follows the van’t Hoff equation with the formation energy decreasing with increasing ion dose. These findings offer valuable insights for enhancing UV-resistant devices and advancing UV color center lasers, which are expected to drive advancements in materials science and optical technologies.