Optical, luminescence and scintillation characteristics of Gd(3)Sc(2)(Al(3-x)Ga(x))O(12): Ce,Mg (x = 0, 1, 2) single crystalline films
Abstract
Optical, luminescence and scintillation characteristics of Ce(3+) - doped Gd(3)Sc(2)(Al(3-x)Ga(x))O(12) (x = 0, 1, 2) single crystalline films fabricated by the liquid phase epitaxy (LPE) technique are investigated. A blue shift of the photo-and radio-luminescence spectra is observed as Ga content increased due to a decrease in crystal field splitting of the Ce(3+) 5d levels.
Temperature-dependent characteristics of radioluminescence (RL) intensity and photoluminescence (PL) decay time are investigated. At room temperature, the decrease of PL- & RL- intensity and PL decay time with increasing Ga content can be explained by thermal ionization of the Ce(3+) 5d(1) excited state.
Gd(3)Sc(2)Al(2)GaO(12):Ce exhibits the highest light yield (LY alpha) value of 1010 ph/MeV along with fast scintillation decay time of 12 ns (27%) + 52 ns (73%) under excitation with 5.5 MeV alpha - particles. Shortening of scintillation decay time with a decrease of the LY value is also obtained in Mg(2+)-codoped samples.