Influence of gamma-irradiation on the optical and structural properties of Se85Te15-xBix nano-thin chalcogenide films

In this work, bulk Se85Te15-xBix chalcogenide glasses were synthesized by melt quenching technique. The nanothin chalcogenide films of Se85Te15-xBix alloys with thickness 40 nm were deposited on glass/Si wafer by Physical Vapour Condensation Technique (PVCT). Their optical and structural properties were analysed by the exposure of different gamma irradiation doses. High resolution X-ray diffraction (HRXRD) and field emission scanning electron microscopy (FESEM) were used to demonstrate the crystalline and morphological properties. The phase transformation studies of nano-thin films were carried out before and after irradiation by 3, 6, and 9 kGy doses of gamma (gamma) rays. The optical parameters such as absorption coefficient, Urbach tail and extinction coefficient were found to be varied with the gamma irradiation doses. Importantly, the indirect allowed band gap increased as increasing the gamma irradiation doses. These notable shifts in the optical band gap and absorption coefficient values can be explained by the increment in disorderness and lattice strain due to gamma irradiation.

Automated summary

Bulk Se85Te15-xBix chalcogenide glasses were synthesized using melt quenching technique, and nanothin chalcogenide films of Se85Te15-xBix alloys were deposited on glass/Si wafer by PVCT. The optical and structural properties were analyzed by exposing the films to different doses of gamma irradiation, which led to variations in optical parameters and an increase in indirect band gap with higher irradiation doses. These changes were attributed to increased disorder and lattice strain caused by gamma irradiation.