Optical properties upon vacuum ultraviolet excitation of sol-gel based Y3Al5O12:Tb3+, Ce3+ powders

Optical properties in the vacuum ultraviolet (VUV) region of cerium and terbium activated Y3Al5O12 powders obtained by the sol-gel process were investigated at room and low temperatures. Both Tb3+ and Ce3+ doped samples exhibited a broad absorption band within the conventional Xe-Ne plasma emission range (140–190 nm). Optimal doping rates have been determined for both rare-earth ions. Emission spectra from cerium doped samples were recorded at 8.2 K and uncovered the splitting of the ground state of Ce3+ ions. Decay times of Ce3+ fluorescence can be fitted by double exponential curves, which can be ascribed to a retrapping phenomenon. Eventually, optical characteristics of codoped Y3Al5O12:(Tb,Ce) and Y3Al5O12:(Tb,Gd) were studied.