Fabrication, tunable fluorescence emission and energy transfer of Tm3+-Dy3+ co-activated P2O5-B2O3-SrO-K2O glasses

A growing demand for white light-emitting diodes (W-LEDs) gives rise to continuous exploration of functional fluorescence glasses. In this paper, Tm3+/Dy3+ single- and co-doped glasses with composition (in mol%) of 30P(2)O(5)-10B(2)O(3)-23SrO-37K(2)O were synthesized using the melt-quenching method in air. The physical properties, glass structure, luminescence characteristics and energy transfer mechanism of the glasses were systematically studied. As glass network modifiers, Tm3+ and Dy3+ ions can densify the glass structure. Excitation wavelength and doping concentration of Tm3+/Dy3+ ions have a direct impact on the emission intensities of blue and orange light as well as the color coordinate of the as-prepared glasses. A white light very close to standard white light can be obtained under 354 nm excitation when the content of Tm3+ and Dy3+ is 0.2 mol% and 1.0 mol%, respectively. The results of the emission spectra and decay curves reveal the existence of energy transfer from Tm3+ to Dy3+. The analytic results based on the Inokuti-Hirayama model indicate that the electrical dipole-dipole interaction may be the main mechanism of energy transfer. Moreover, Tm3+/Dy3+ co-activated glass phosphor has good thermal stability and chrominance stability and it is a promising candidate for white LEDs and display device.