Abstract
The luminescence kinetics of Ti(3+) ions, resulting from the spin-allowed (2)E → (2)T(2) electron transition, are generally expected to be fast, within the microsecond range. However, in this study, we observed average lifetimes of up to 30 ms in nanocrystalline LaAlO(3):Ti(3+) powders. Our detailed analysis of the spectroscopic and thermoluminescence properties of LaAlO(3):Ti(3+) suggests that this prolonged Ti(3+) kinetics is associated with the presence of electron traps and the proximity of the Ti(3+) excited state to the conduction band, which facilitates energy transfer between them. Furthermore, the observed shift in Urbach states with an increasing Ti(3+) concentration correlates with the efficiency of energy transfer between deeper traps and Ti(3+) ions. This study provides a comprehensive strategy for controlling the luminescence kinetics of Ti(3+) ions through electron trap engineering, induced by dopant ion concentration, which can be applied in various fields including luminescence thermometry.