Influence of gamma radiation on the optical, morphological, structural and electrical properties of electrodeposited lead selenide nanowires

Abstract

The influence of gamma radiation exposure is studied on the optical, morphology, structural and electrical properties of PbSe nanowires with 100 nm diameter. The PbSe nanowires are synthesized by template-based electrodeposition technique. Samples are exposed using Co60 gamma source at different doses. Gamma radiation is electromagnetic radiation with high energy, frequency and penetrating power. Gamma radiations at precise doses can tune the physical properties of PbSe nanowires as infrared detectors for various applications. The optical study was carried out using UV–Vis NIR spectroscopy in reflectance mode. Further, the optical parameters such as bandgap, refractive index, static and high-frequency dielectric constant were calculated for pristine and gamma radiation exposed PbSe nanowires. The bandgap as calculated from Kubelka-Munk function decreased from 0.74 eV to 0.60 eV with an increase in dose from pristine to 200 kGy. The morphology of the nanowires was recorded using scanning electron microscopy. The nanowires obtained are cylindrical in shape and uniform throughout the length. The detailed analysis of the structural properties of PbSe nanowires is done using Scherrer and W–H methods. The preferred orientation of planes was determined by texture coefficient analysis. Strain, stress and energy density is calculated for the most preferred plane as obtained in texture coefficient (TC) analysis. The I–V characteristics is calculated before and after gamma exposure. In Raman spectra, the evolution of 2LO vibrational mode was observed with an increase in gamma radiation dose. The I–V characteristics represent space-charge limited conduction (SCLC) behaviour and an increase in current with increase in gamma dose for PbSe nanowires which makes it important for various potential applications in optoelectronic devices.