White light emission from Eu3 +/Tb3 +/Tm3 + triply-doped aluminoborate glass excited by UV light

The Eu^3 +/Tb^3 +/Tm^3 + triply-doped glasses with the composition of CaO―Al₂O₃―B₂O₃―RE₂O₃ (RE = Eu,Tb,Tm) have been synthesized by melt quenching method. The photoluminescence of these Eu^3 +/Tb^3 +/Tm^3 + triply-doped glasses (CaAlB:RE^3 +) were studied and the emission spectra combining with blue, green and reddish orange bands were observed. Under 360 nm wavelength excitation the white light emission is achieved when the concentration (x) of Tm^3 + in Ca_0.931 ?xAlB:Eu^3 +_0.038,Tb^3 +_0.031,Tm^3 +_x glass is in the range of 0.0013-0.011 per mol matrix. In addition, the energy transfer (ET) between Tb^3 + and Eu^3 + ions in Eu^3 +/Tb^3 +/Tm^3 + triply-doped glasses was validated and the electric dipole–dipole interaction is responsible for the ET process of Tb^3 + → Eu^3 + at low concentrations. Hence, the Eu^3 +/Tb^3 +/Tm^3 + triply-doped aluminoborate glass could be a potential candidate for white LEDs.