Structural, optical and electrical properties of gamma-rays exposed selenium nanowires

The increasing use of semiconducting nanowires in applications that require prolonged exposure to high energy photons (X-rays and gamma rays) necessitates a better understanding of the effects of irradiation on them. In this context, we synthesized selenium nanowires of 80 nm diameter using template assisted electro-deposition technique and exposed them to gamma rays using Co-60 source at Inter University Accelerator Centre, New Delhi, India. The effect of gamma irradiation on their structural, optical and electrical properties was investigated. The analysis of XRD of pre- and post- irradiated Se nanowires showed no shifting in the peak positions. However, Texture analysis demonstrates the variation in the relative intensity with changing preferred orientation at the higher doses. The optical study was done using UV–Vis spectrophotometer and was found that the optical band gap decreased with increasing gamma irradiation dose. Current–Voltage characteristics of pristine and irradiated Se nanowires also exhibit an enhancement in the current with the exposed dose. The decrease in band gap and an increase in current conduction may be attributed to the decrease in scattering of charge carriers from the grain boundaries and creation of more number of electron-hole pairs.