Optical and structural properties of ZnGa2O4: Eu3+ nanophosphor by hydrothermal method

Nanophosphor of ZnGa2O4:Eu3+ was synthesized through a hydrothermal method. The particle size was about 20 nm confirmed by X-ray diffractometry and scanning electron microscopy. Excitation peaks attributed to the charge transfer of Eu–O were redshifted to longer wavelength sides. Red emission peaks originating from 5D–7Fj (image) transitions of Eu3+ were split into two sub-bands, indicating that two different Eu3+ ions exist at tetrahedral Zn2+ and octahedral Ga3+ sites. Relative intensities of two sub-bands were different from those of bulk phosphor. The color purity of ZnGa2O4:Eu3+ nanophosphor is enhanced in comparison with that of bulk phosphor. Optical characteristics of ZnGa2O4:Eu3+ nanophosphor can be explained by different site occupancy of Eu3+ from ZnGa2O4:Eu3+ bulk phosphor.