Enhancing UV light sensitivity of PVP polymer by doping chromium trioxide via the electrospun solutions

Abstract

Herein, chromium trioxide (Cr2O3) doped Polyvinylpyrrolidone(PVP) nanofibers with high crystallinity and UV light sensitivity are successfully grown onto the glass substrates by electrospun deposition at room temperature. The effect of Cr2O3 concentration on the morphology, structure, and photoluminescence properties of the as-fabricated PVP nanofibers is examined. With the increase in doping concentration of Cr2O3 (i.e., 1, 2 and 3 %), the direct band gap of PVP nanofibers is reduced to 4.05, 4.01, and 3.85 eV, respectively. XRD and FE-SEM results manifest that the crystallinity and diameter of the nanofibers are dependent upon Cr2O3 concentration, i.e., the mean diameter decreases from 600 to 200 nm. Photoluminescence spectra indicate higher UV emission upon the addition of Cr2O3, with greater emission near the band edge for thinner nanofibers. A possible mechanism for the formation of PVP/Cr2O3 nanofibers is addressed in detail. Furthermore, it is found that the sensitivity of the as-fabricated PVP/Cr2O3 detector to UV-light emission strongly depends on Cr2O3 concentration, i.e., good responsivity (2.257 A/W) and specific detectives (9.8 × 1012 cm Hz1/2/W) at a Cr2O3 concentration of 2 % are achieved at a wavelength of 454.1 nm, besides recording the lowest rise and fall times.