Optically stimulated luminescence radiation response of Au/Al2O3 phosphors

Crystal defects such as the doping of a variety of various elements are known to enhance the optically stimulated luminescent dosimeter (OSLD) performance of Al2O3. Moreover, the use of Au nanoparticles (NPs) has attracted considerable attention because of their photoluminescence properties. In this paper, a facile method is proposed to prepare and disperse Au NPs on an Al2O3 surface. The effects of Au nanoparticles on linearity between light emission and dose, reusability, and angular dependence of our proposed Au/Al2O3 OSLD are examined and discussed. We found that the linearity between light emission and dose with a wider dose range from 5 Gy to 30 Gy can be obtained. The sensitivities were tuneable by adjusting the Au/Al2O3 ratio. The result also shows a comparable angular dependence properties with commercially-available Al2O3:C dosimeters. In addition, the optical bleaching durations of Au/Al2O3 and Al2O3:C phosphors were also studied, in which the required bleaching time for our proposed Au/Al2O3 was 2 h shorter than for Al2O3:C. In other words, this research also helps to reduce the bleaching time before re-use.