Sensitized deep-UV excitation of Tm3+ ions in strontium phosphate glasses with Sb3+ co-doping

The novel Tm3+/Sb3+ co-doped phosphate glasses are studied in response to an improvement of blue light emitting source. The analysis of J-O intensity parameters suggests that the present strontium phosphate glass is an appropriate matrix for Tm3+ doping to obtain an enhanced blue emission. The 5 s2-type Sb3+ ion serves as a sensitizer to transfer its strong allowed excitation in the deep UV region to Tm3+ effectively. PL and PLE spectra show that by Sb3+ co-doping, the blue emission of the Tm3+ doped strontium phosphate glass is enhanced greatly, while the excitation band of Tm3+ extends largely to the deep UV region. The emission decay curves of Sb3+ demonstrate the existence of the energy transfer (ET) process from Sb3+ to Tm3+ with the maximum efficiency and probability of ET as 20.43% and 9.20%, respectively. The emission color of these glasses can be adjusted from warm to cold blue via modulating excitation wavelengths. The present work suggests that Sb3+/Tm3+co-doped strontium phosphate glasses are promising for applications in blue emitters and plasma display panels.