The role of capping agents on the trapping levels structure and luminescent emission of SrMoO4 phosphors

Abstract

In the present work, we investigate the thermoluminescence (TL) and optically stimulated luminescence (OSL) from strontium molybdate SrMoO4 powders designed with different capping agents. The samples were prepared through co-precipitation and processed in a Microwave-Assisted Hydrothermal (MAH) system. The structural, optical, and morphological characteristics were investigated using Raman, Fourier transform infrared spectroscopy (FTIR), DRX, ultraviolet-visible (UV–vis) absorption, and Scanning electron microscopy (SEM). The TL glow curves recorded from as-prepared and irradiated samples with beta particles reveal that their intensity and profile depend on the used capping agent. The trapping depth energy, determined from the TL glows curves, ranges from 1.02 to 2.23 eV for the as-prepared samples and from 0.9 to 2.33 eV for the irradiated phosphors. The residual TL spectra, registered from successive readouts, reveal that the thermal treatment shifts the glow curve to lower temperatures suggesting the formation of shallower trap states. The results reveal that the OSL signal and its behaviors with the radiation dose depending on the employed capping agent. The results show the TL and OSL signal's dependence on the structural properties and support the potential application of SrMoO4 powders as an OSL detector.