Effect of Ga3+ ion doping on emission thermal stability and efficiency of MgAl2O4:Cr3+ phosphor

In this work, we fabricated a novel spinel-type phosphor material MgAl2-xGaxO4 doped with Cr3+ by the high-temperature solid-state sintering method. The crystal field environment of the spinel was tuned by replacing the Al ions with Ga3+ ions of different concentrations. The cell volume and D-q/B gradient increase from 2.82 to 2.62 with increasing Ga3+ ion doping concentration. This also implies a gradual decrease in the field strength of the crystal. Based on this, the excitation spectra of MgAl1.995-xGaxO4:0.5%Cr3+ phosphors yield a redshift. Increasing the Ga3+ ion doping concentration also improves the emission intensity and thermal stability of the phosphors, and the emission intensity of the Ga3+-doped phosphors is significantly increased. For a Ga/Al ratio of 1, the thermal stability of the phosphor emission is optimal. The emission intensity at 140 & DEG;C can maintain 76% of the emission intensity at room temperature, indicating that appropriate Ga3+ ion doping can improve the emission efficiency and thermal stability of the phosphors.

Automated summary

In this study, a novel spinel-type phosphor material MgAl2-xGaxO4 doped with Cr3+ was fabricated using the high-temperature solid-state sintering method. The crystal field environment of the spinel was adjusted by replacing Al ions with Ga3+ ions of varying concentrations. Increasing the Ga3+ ion doping concentration resulted in larger cell volume and D-q/B gradient, indicating a decrease in the crystal's field strength. The excitation spectra of MgAl1.995-xGaxO4:0.5%Cr3+ phosphors showed a redshift. Additionally, higher Ga3+ ion doping concentration improved the emission intensity and thermal stability of the phosphors.