Sensitizing effects of Sn2+ ions on Tm3+ emissions for deep UV excitation in phosphate glasses

In the present work, Tm3+-doped strontium phosphate glasses modified by Sn2+ are investigated. Sn2+ and Tm3+ can be co-excited with the deep UV light to emit the tunable blue light. The reinforced and purified blue emission is obtained at the excitation bands toward the deep-UV part of the spectrum. Photoluminescence emission and excitation spectra, and emission decay curves indicate consistently that the improved Tm3+ emission is in association with the presence of Sn2+ in the host glass where energy transfer from Sn2+ to Tm3+ occurs. Relevant mechanism is discussed.