Energy transfer and color-tunable luminescence properties of NaCaBO 3 :RE 3+ (RE 3+ = Tm 3+ , Dy 3+ , Tm 3+ /Dy 3+ ) phosphors

Abstract The Tm3+-doped, Dy3+-doped and Tm3+/Dy3+-codoped NaCaBO3 compounds were produced via a solid-state reaction process. The optimum doping concentrations for Tm3+ and Dy3+ ions in NaCaBO3 were determined to be 2 and 3 mol%, respectively. Under 358 nm excitation, the characteristic emission bands of the dopants were detected in the synthesized compounds. Besides, the emitting color of the obtained products was shifted from blue to pure white as a result of the efficient energy transfer (ET) from Tm3+ to Dy3+ ions. According to the PL emission intensity, the ET efficiency was calculated and found to be elevated with the introduction of the activators and the maximum efficiency was around 89.4%. The dipole–dipole interaction contributed to the ET from Tm3+ to Dy3+ ions. Additionally, the temperature-dependent PL emission spectra suggested that the as-synthesized phosphors possessed good thermal stability. Also, the NaCaBO3:Tm3+/Dy3+ phosphors possessed strong CL properties.