Luminescence properties of Eu3+-doped potassium-gadolinium-phosphate glasses

초록

Eu<inf>2</inf>O<inf>3</inf>-doped K<inf>2</inf>O-Gd<inf>2</inf>O<inf>3</inf>-P<inf>2</inf>O<inf>5</inf> glasses were fabricated using the melt-quenching technique. The result indicates that the glasses' density and refractive index increase while the molar volume decreases from 0.05 to 0.5 mol% and then increases from 0.5 to 2 mol% with increased Eu<inf>2</inf>O<inf>3</inf> concentration. The absorption spectra in the UV-Vis and NIR regions exhibit an energy transition from a ground state to possible excited states for 7F<inf>0</inf> → 5K<inf>5</inf>, 7F<inf>0</inf> → 3P<inf>0</inf>, 7F<inf>1</inf> → 5G<inf>2</inf>, 7F<inf>0</inf> → 5L<inf>6</inf>, 7F<inf>1</inf> → 5D<inf>3</inf>, 7F<inf>0</inf> → 5D<inf>2</inf>, 7F<inf>1</inf> → 5D<inf>1</inf> and 7F<inf>0</inf> → 7F<inf>6</inf>, and 7F<inf>1</inf> → 7F<inf>6</inf>. The luminescence characteristics were examined by photoluminescence (PL) and radioluminescence (RL). Both PL and RL confirmed that the optimum value at 2 mol% of Eu<inf>2</inf>O<inf>3</inf> concentration. Similarly, the luminescence efficiency of 2 mol% Eu<inf>2</inf>O<inf>3</inf> concentration compared with the BGO crystal equals 16.77%. As the concentration of Eu<inf>2</inf>O<inf>3</inf> increased, the experimental decay curve dropped while the energy transfers efficiency (ɳ<inf>ET</inf>) and the energy transfer parameter (Q) raised. Interestingly, the CIE of emission spectra under 393 nm (UV lamp) were reddish orange (0.64, 0.35). The branching ratio (β<inf>R</inf>) was most significant at 612 nm, and the JO parameter trend was Ω<inf>2</inf> > Ω<inf>6</inf> > Ω<inf>4</inf>. Furthermore, all characterizations confirm its applicability in optical display devices. © 2024

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