Effect of P(2)O(5) Content on Luminescence of Reduced Graphene-Oxide-Doped ZnO–P(2)O(5) Nano-Structured Films Prepared via the Sol–Gel Method

A convenient and low-cost sol–gel approach for the one-step synthesis of ZnO–P(2)O(5)–rGO nanostructures with tuned bandgap and fluorescence was investigated. The obtained hybrid nanostructures exploit the properties of zinc oxide, graphene oxide and phosphorous oxide as promising candidates for a wide range of optoelectronic applications. A predominant amorphous structure, ZnO–P(2)O(5)–rGO, containing ZnO nanorods was evidenced by X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). The estimated size of the ZnO nanorods in nanostructures with P(2)O(5) was noticed to decrease when the P(2)O(5)/ZnO ratio was increased. The presence of ZnO, P(2)O(5) and rGO was confirmed by Fourier-transform infrared spectroscopy (FTIR) and Raman investigation. P(2)O(5) was noticed to tune the bandgap and the fluorescence emissions of the nanostructured films, as estimated by UV–Vis–NIR and fluorescence spectroscopy, respectively. The electrical measurements performed at room temperature showed that the main influence on the film’s resistivity does not come from the 1% rGO doping but from the P(2)O(5)/ZnO ratio. It was found that a 10/90 molar ratio of P(2)O(5)/ZnO decreases the resistivity almost seven-fold compared with rGO-doped ZnO films.