Role of Lithium Codoping in Enhancing the Scintillation Yield of Aluminate Garnets

• DOI: 10.1103/physrevapplied.13.064060
• Publication Date: 2020-06-26T12:01:16Z
• Authors: Yuntao Wu; Ge Yang; Dan Han; Ming Liu; Ayman Hawari; Mao-Hua Du; Jing Peng; Camera Foster; Shiyou Chen; Merry Koschan; Charles L. Melcher
• Keywords: 0103 physical sciences; 01 natural sciences

The aim of this work is to clarify the scintillation-yield enhancement in $\mathrm{Lu}\mathrm{YAG}:\mathrm{Pr}$ scintillators obtained by $\mathrm{Li}$ codoping via integrated study valence state activators, preferential site occupancy codopants, and defect structures from experimental theoretical insights. With codoping, light yield energy resolution $10\ifmmode\times\else\texttimes\fi{}10\ifmmode\times\else\texttimes\fi{}10\phantom{\rule{0.1em}{0ex}}{\mathrm{mm}}^{3}$ samples are improved 15 600 24 800 photons/MeV, 5.3 4.3% at 662 keV, respectively. optical absorption spectra indicate that does not induce conversion stable ${\mathrm{Pr}}^{3+}$ ${\mathrm{Pr}}^{4+}$ single crystals. Based on formation energies substitutional interstitial sites using density-functional-theory (DFT) calculations ${}^{7}\mathrm{Li}$ nuclear magnetic resonance results, it shown ions prefer dominantly occupy fourfold coordinated $\mathrm{Al}$ sites. systematic analysis thermoluminescence glow curves, positron annihilation lifetime spectroscopies, derived DFT reveals concentration isolated $\mathrm{Lu}$ vacancies as dominant acceptor defects reduced whilst shallow ${\mathrm{Li}}_{i}$ deep ${V}_{O}$ oxygen introduced simultaneously. We propose lowering hole trapping resulting contributes enhancement.