Fabrication and characterization of a new flexible ionizing ray sensor based on lead tungstate (PbWO4)

Abstract

In this study, a cost-effective, flexible ionizing ray sensor based on lead tungstate nanoparticles (PbWO4 NPs) was fabricated. PbWO4 NPs were successfully synthesized via the co-precipitation method. Synthesized NPs were embedded in a polystyrene matrix (PS) to form a composite film. The prepared samples' optical response and structural features were investigated under ultraviolet, 980 nm diode laser, and ion beam induced luminescence excitations, along with XRD, XPS, Raman, EDX-Mapping, FESEM, TEM, AFM, and FTIR measurements. Also, the ionizing radiation sensitivity of the prepared composite film was investigated using 241Am and 137Cs sources. XRD, XPS, FTIR, and EDX-Mapping elemental results showed characteristic peaks of PbWO4 and related elements in the samples. TEM image showed that NPs are approximately 37 nm in diameter. Using Monte Carlo simulation algorithm, the range of alpha particles passing through PbWO4 and PS individually were obtained to be∼21 and 30 μm, respectively which were in good agreement with FESEM images. The band gap energy of the prepared nanopowders was obtained to be 3.40 eV. AFM topography images of the composite film showed that PbWO4 NPs were incorporated into the PS matrix with a Root Mean Square (RMS) roughness of 29.23 nm. According to the measurements, the flexible PbWO4 film showed good luminescent stability for more than three days in the floating water, prominent blue-green centered at 400–500 nm visible regions with an energy transfer efficiency of 89.3% and high ionizing ray sensitivity of 80% which is comparable with commercial ZnS: Ag. The results indicate that prepared nanocomposite has the potential for practical applications in future optoelectronic fields and wearable displays.