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Co-doping has been demonstrated to improve the light yield and/or energy resolution for compounds activated with Ce [1] and Tl [2]. Limited efforts have been done for co-doping of Eu-activated halides. We report on the screening of co-dopants for the mixed halide BaBrCl:Eu. With a light output of 52,000 photon/MeV and energy resolution of 3.55%, theoretical performance of BaBrCl:Eu has not been achieved. Among a large number of aliovalent/isovalent co-dopants tested experimentally, Au, at low concentration, was found to give the best enhancement for the scintillator characteristics. We fount that co-doping with Au significantly improve the light output of BaBrCl:Eu for all Eu concentration in the range of 0.5%<Eu<8% with the optimum being at 3%. The results have a direct impact on the crystal growth process, as large concentration of Eu has been related to cracking of the crystals. The role of Au co-dopant in scintillation mechanisms of BaBrCl:Eu single crystals will be discussed considering the results of first-principal calculations and the defect structure of the compound.
[1] M. NIkl and A. Yoshikawa. Advanced Optical Materials 2015 3, 463-481.
[2] I. V. Khodyuk, S. A. Messina, T. J. Hayden, E. D. Bourret, and G. A. Bizarri.
J Apply Physics 118 (2015) 084901
[3] Y. Zewu, T. Shalapska, E. D. Bourret-Courchesne J. Crystal Growth 435 (2016) 42
This work is supported by the Department of Energy, National Nuclear Security Administration, Office of Defense Nuclear Nonproliferation Research and Development and carried out at Lawrence Berkeley National Laboratory under contract #AC02-05CH11231. This work does not constitute an express or implied endorsement on the part of the government.
