Enhanced broadband orange-red emission of Eu³⁺ via Sm³⁺ co-doping in YAlO₃ single crystal

Sm3+/Eu3+: YAlO3 (Sm3+/Eu3+: YAP) single crystal with a size of Ф (25-35) mm × (50-60) mm was successfully grown and analyzed. The use of Sm3+ co-doping to enhance Eu3+: 5D0 → 7F2 orange-red emission has been investigated in the YAP crystal for the first time. Compared with the Eu3+ single-doped YAP crystal, the Sm3+/Eu3+ co-doped YAP crystal possessed a larger fluorescence emission cross section (0.90×10−21 cm2), higher quantum efficiency (78.4%), and comparative fluorescence lifetime (1.74 ms), corresponding to the stimulated emission of Eu3+: 5D0 → 7F2 transition. Moreover, the energy transition efficiency of the energy transition process from the Sm3+: 4G5/2 level to the Eu3+: 5D0 level was calculated to be as high as 47.31%. These results suggest that Sm3+ ion can be used as an efficient sensitizer to enhance the orange-red fluorescence emission and can lead to the expansion of the emission range from 585–640 nm in Sm3+/Eu3+ co-doped YAP crystal.