Achieving zero-thermal quenching luminescence in ZnGa2O4: 0.02Eu3+ red phosphor

The struggle with "thermal load" is always an unavoidable challenge for photo-luminescent material. In this work, a novel red phosphor of ZnGa 2 O 4 : Eu 3+ with spinel-type structure is prepared by high-temperature solid-phase method. Due to the charge imbalance during the replacement processes of Ga 3+ →Zn 2+ and Eu 3+ →Zn 2+ in mixed spinel structure, vacancy defects can be introduced into the lattice structure of ZnGa 2 O 4 : 0.02Eu 3+ . The results of Density Function Theory (DFT) calculation demonstrate that the existence of vacancy defects can construct defect energy levels in the energy band structure of the host crystal, which can assist enhancing the fluorescence emission intensity of the phosphor at high temperature. The strong thermal stability of its own structure combined with the assistance of defect energy levels enables the achievement of zero-thermal quenching in ZnGa 2 O 4 : 0.02Eu 3+ under multi-wavelength excitation. Our results open up a new way for the exploration and utilization of zero-thermal quenching phosphors.