Shallow traps and radiative recombination processes in Lu3Al5O12:Ce single crystal scintillator

Thermally stimulated luminescence (TSL) glow curves and emission spectra were studied in undoped and Ce-doped Lu3 Al5 O12 single crystals by wavelength resolved TSL measurements in the 10-310 K temperature range. Isothermal phosphorescence measurements in the 10-100 K range were also performed, which point to the existence of a tunneling-driven radiative recombination process. These processes can explain the presence and time-dependence of the submicrosecond slow decay component in the scintillation decay. Electron paramagnetic resonance experiments suggest the presence of LuAl defects in the vicinity of Ce3+ ions, which are the most probable electron and hole traps participating in the tunneling-driven radiative recombination process. © 2007 The American Physical Society.