Effect of Li⁺, Na⁺, and K⁺ Co-Doping on Structural, Morphological and Luminescent Properties of Ce³⁺/Pr³⁺-Activated Lu₃Al₅O₁₂ Garnet powder scintillators

Abstract

This PhD research investigates the synthesis and the structural, morphological, and optical properties of Lu₃Al₅O₁₂ (LuAG) garnet-based scintillators, doped with Ce³⁺ or Pr³⁺, and co-doped with alkali metal ions (Li⁺, Na⁺, and K⁺) using the sol-gel method. Through experimental studies and theoretical simulations, the effects of alkali codoping on luminescence efficiency, crystallite size, and defect density were systematically analyzed. Li⁺ co-doping was particularly effective in reducing crystallite size, enhancing photoluminescence (PL) and radioluminescence (RL), and minimizing trap densities, thereby improving scintillation efficiency and charge transport. Moreover, RL studies revealed faster scintillation compared to single crystals, with no afterglow observed. For LuAG:Pr³⁺, Li⁺ also enhanced emission intensity and decay characteristics,reinforcing its potential for fast scintillation applications. These findings emphasize the importance of defect control and codoping strategies in optimizing garnet-based scintillators, positioning them as promising candidates for advanced radiation detection and optical technologies.