Nano-Ag doping induced changes in optical and electrical behaviour of PVA films

Hybrids of nano-Ag and PVA films prepared via sol–gel method have been characterized through XRD, TEM, UV–vis spectroscopy and I–V measurements. The change in optical band gap value and room temperature dc conduction behaviour of undoped and nano-Ag doped PVA films have been studied. The value of optical band gap has been found to be reduced from 4.92 eV (for undoped PVA) to 3.93 eV on doping 1.32% (by wt.) nano-Ag in PVA. This decrease in optical band gap and observed increase in conduction can be correlated to the formation of the charge transfer complexes within the polymer network on dispersing nano-Ag in it. Current–voltage behaviour suggests that Poole–Frenkel mechanism is primarily responsible for the observed conduction for both undoped and nano-Ag doped PVA films.