Luminescence properties of BeO optically stimulated luminescence (OSL) detectors

The objective of this work is to investigate basic luminescence properties of BeO optically stimulated luminescence (OSL) detectors, including the OSL emission and stimulation spectrum, the lifetime of the luminescence centers contributing to the OSL signal, and the temperature dependence of the luminescence lifetime and of the luminescence efficiency. The OSL stimulation spectrum shows a continuous increase in OSL intensity with decreasing stimulation wavelength. The emission spectrum indicates two OSL emission bands at ～310 nm and ～370 nm, the latter being the dominant OSL emission band. We also observed that the luminescence centers associated with the OSL signal are strongly quenched above room temperature, resulting in a reduction in luminescence lifetime from ～27 μs at room temperature down to ～800 ns at 140 °C. The activation energy for non-radiative decay of the luminescence center was determined to be E = (0.568 ± 0.023) eV. The ～27 μs luminescence lifetime observed for BeO indicate that POSL technique may be used to improve the signal-to-noise ratio using stimulation pulses of the order of microseconds. The information obtained in this study may help further optimize the BeO dosimetry systems and provide guidance on the timing parameters to be used for POSL measurements of this material.