YAl3(BO3)4: Tm3+/Ho3+nanophosphors for blue-LED applications

The YAl3(BO3)4 nanophosphors activated with different concentrations of Tm3+/Ho3+ were synthesized by conventional solid-state reaction technique sintering at 1200 oC for 3 hours. Upon 359 nm near UV excitation, the YAl3(BO3)4:Tm3+/Ho3+ nanophosphors emit intense blue luminescence through Tm3+:1D2 → 3F4 (456 nm) and Tm3+:1G4 → 3H6 (481 nm) transitions. A quenching in luminescence was noticed beyond xTm3+/ yHo3+ (x = 1.0 mol% and y = 0.5 mol%) due to energy transfer at higher Tm3+ ions concentration through cross-relaxation mechanism. The experimental results show that the YAl3(BO3)4:xTm3+/yHo3+ (x = 1.0mol% and y = 0.5mol%) nanophosphors excited at 359 nm near UV radiation could be the best…