Increased luminescence and improved decay kinetics in lithium and cerium co-doped yttrium aluminum garnet scintillators grown by the Czochralski method

In this study, four yttrium aluminum garnet single crystals co-doped with cerium and lithium were produced by the Czochralski method and the scintillation and defect properties were investigated. Our results demonstrated an increase in luminescence with Li co-doping as well as elimination of longer decay times. Surprisingly, although Li is monovalent, no oxidation of cerium from Ce³⁺ to Ce⁴⁺ was found as would be expected to maintain charge neutrality. Additionally, thermoluminescence results indicated a reduction in the trapping of charge carriers by shallow and deep traps, and room temperature photoluminescence measurements showed an improvement in the Ce³⁺ 5d to 4f transition efficiency.