Synthesis & thermoluminescence characteristics & structural and optical studies of ZnO/Ag/ZnO system for dosimetric applications

This study demonstrated a novel dosimeter ZnO/Ag/ZnO) multilayer thin films that were fabricated via radiofrequency and direct current RF/DC sputtering at room temperature. The sequence of ZnO_{(200 nm)} Ag_{(x nm)} ZnO_{(50 nm)} was selected with Ag layer of varying thickness (x = 5, 10, 14, 20, 30, and 40 nm). The dosimetric properties were investigated where samples were irradiated with X-ray doses in the range of 0.01–4 Gy. The optimum TL intensity found at ZnO_{(200 nm),} Ag_{(10 nm)} ZnO_{(50 nm)}. The glow curve revealed a single peak, the dosimetric peak consistent to 230 °C. In contrast, the best heating rate and annealing temperature and time recorded 3 °C/s, 200 °C, and 30 min respectively. The dose-response demonstrated good linearity within the dose range of 0.01–4 Gy. The other properties have been studied, such as reused, thermal fading, and optical fading; the results in this study revealed that the new host dosimeter exhibits a suitable TL property for radiation detection. The Photoluminescence PL study depicted two sharp peaks of ZnO/Ag/ZnO multilayer thin films at both visible regions at 740–810 nm and UV region of 380 nm (band-edge), corresponding to deep-level emission (DLE) and exciton emission respectively. X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), energy dispersive x-ray (EDX), and Ultra-Violet Visible (UV–Vis) were utilized to study crystalline structure, morphology, and element composites and optical properties respectively.