Study on the Effect of [gamma]-Irradiation on Gadolinium Oxysulfide Nanophosphors (Gd2O2S-NPs)

Gadolinium oxysulfide nanophosphors (Gd2O2S-NPs) have been successfully synthesized using γ-irradiation and hydrogenation treatment. The primary stage of Gd2O2S-NPs synthesis was carried out using various doses of γ-irradiation to form diverse sizes of Gd2(SO4)3 precursor, followed by hydrogenation treatment at 900°C for 2 hours to form Gd2O2S-NPs. Then, the nanophosphors were characterized for the structure, morphology, and luminescence properties through X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and photoluminescence spectrometer (PL). Pure hexagonal phase of Gd2O2S-NPs was obtained with high crystallinity and without any impurities. The morphologies were observed from grain-like nanostructures transformed to spherical shape as the irradiation dose reached 40 kGy. Besides, Gd2O2S-NPs which were prepared at highest irradiation dose of 40 kGy show highest intensity of emission peak at 548 nm and corresponded to Stark level transition from the [subscript]GJ[/subscript] 6 state of Gd3+ ion. It can be emphasized that the different doses of γ-irradiation influenced the nucleation event of Gd2(SO4)3 precursor thus affecting the morphology and size particles of Gd2O2S-NPs. Hence, from the results, it can be suggested that Gd2O2S-NPs can be a promising host for optical applications.