Carrier mechanism of ZnO nanoparticles-embedded PMMA nanocomposite organic bistable memory device

Abstract

ZnO nanoparticles embedded polymethylmethacrylate (ZnO-PMMA) organic bistable memory device was fabricated by sol-gel spin coating technique. ZnO-PMMA thin films were deposited on ITO coated glass substrates (Al/ZnO-PMMA/ITO). XRD and SAED patterns of ZnO-PMMA nanocomposite thin films showed the polycrystalline behavior. FTIR peaks of ZnO-PMMA nanocomposite thin films were observed at 540 cm(-1) for Zn-O bond and at 1766 cm(-1) for ester carbonyl C=O stretch vibration of PMMA. The bandgap of ZnO-PMMA thin films was observed to be lower (3.07 eV) than the pure ZnO (3.20 eV), while the PL peak was observed at a wavelength of 403 nm. Current-voltage (I-V) measurements of the device, Al/ZnO-PMMA/ITO showed a nonvolatile electrical bistable behavior at room temperature. The ON to OFF current ratio of the bistable device was found to be similar to 10(4), which confirmed the write and the read sequence and discussed the carrier transport mechanism.