Optical, luminescence and scintillation characteristics of Bi-doped LuAG and YAG single crystalline films

Bi-doped Lu3Al5O12 (LuAG) single crystalline films (SCFs) of thickness within 8?31??m were grown by the liquid-phase epitaxy method onto Y3Al5O12 (YAG) single crystal substrates using a melt solution based on a Bi2O3 flux. Their characteristics were compared with YAG?:?Bi SCFs grown at the same conditions. The concentration of Bi3+ ions in LuAG?:?Bi and YAG?:?Bi SCFs was varied by changing the growth temperature in the ranges 0.05?0.18?at% and 0.13?0.57?at%, respectively. The absorption, luminescence and scintillation properties of these SCFs noticeably depend on the Bi3+ concentration. Luminescence spectra of both LuAG?:?Bi and YAG?:?Bi SCF consist of two broad emission bands in the UV and visible (VIS) spectral ranges peaking at 4.155?4.085?eV and 2.45?2.66?eV, respectively. Both the UV and VIS luminescence show complex non-exponential decays. Under 241Am ?-particle excitation the photoelectron yield of the best performing LuAG?:?Bi (0.18?at%) and YAG?:?Bi (0.13?at%) SCFs is about 15% and 21%, respectively, of that of the reference YAP?:?Ce single crystal.