Suppression of defect related host luminescence in LuAG single crystals

To study suppression of the unwanted host luminescence in aluminum garnet crystals, effect of Ga substitution in both undoped and Eu doped Lu3Al5O12 single crystal was examined at the crystals grown by the micro-pulling down(μ-PD) method. Optical properties such as excitation spectra, radioluminescence spectra and photoluminescence decay are presented. In the GA-admixed crystal strong suppression of host luminescence due to an exciton localized around the Lu-Al antisite defect was observed even at the Ga concentration of 10 mol%. Ga substitution also modify the charge transfer excitation band in the Eu doped LuGAG and change the decay time in the Eu3+ red emission lines.