Physical and optical studies of Gd 2 O 2 S:Eu 3+ nanophosphors by microwave irradiation and γ‐irradiation methods

Gd 2 O 2 S:Eu 3+ nanophosphors have been successfully synthesized using microwave irradiation and γ‐irradiation methods with polyvinyl pyrrolidone as a stabilizer. The physical and luminescence spectra were compared. The morphologies of both Gd 2 O 2 S:Eu 3+ nanophosphors were in the hexagonal phase and mainly consisted of spherical nanostructures with diameters of ~90 nm and ~50 nm for both microwave irradiation and γ‐irradiation methods. Upon 325 nm of ultraviolet (UV) light excitation, strong red emissions (626 nm) were observed for both methods; these emissions corresponded to the 5 D 0 → 7 F 2 transition of Eu 3+ ions. However, Gd 2 O 2 S:Eu 3+ nanophosphors following microwave treatment showed better luminescence intensity than Gd 2 O 2 S:Eu 3+ nanophosphors treated with γ‐irradiation. This difference was attributed to the crystallinity phase and surface quenching effects of Gd 2 O 2 S:Eu 3+ nanophosphors. The reaction mechanisms of Gd 2 O 2 S:Eu 3+ nanophosphors in both methods are discussed in detail.