Optical sensor developed from nano-silver / poly(vinyl alcohol) composite

Abstract

Abstract Silver nanoparticles were successfully synthesized by 6\u202fMeV electron irradiation process in aqueous solution containing poly(vinyl alcohol) to produce a composite. The resulting composite characterized by UV–Vis spectroscopy, X-Ray diffraction and transmission electron microscopy reveals nucleation and growth of silver nanoparticles with an average diameter of 12\u202fnm and having surface plasmon resonance peak at 395\u202fnm. The nano-silver/poly(vinyl alcohol) composite was then coated on p-type conducting silicon by drop casting method and the ability of the resulting device as a optical sensor was investigated. The novelty of prepared sensor device is its reversible and rapid response, which is proportional to incident light intensity within the range of 20–80\u202fmW/cm2 over a wide optical wavelength region. The Schottky junction showed good rectification and photo-response characteristics within the applied voltage. The photo-current developed was found to increase with increasing incident light intensity. The novelty of the device is its photo-response, which was found to be in good agreement with the transport of optically (surface plasmon) generated charge carriers though charge transfer complexes formed in composite.