Improvement of reliability of polymer nanocomposite based transparent memory device by oxygen vacancy rich ZnO nanorods

Abstract

Different weight percent (wt%) of Zinc Oxide (ZnO) nanorods, prepared by chemical route, are used into polymethylmethacrylate (PMMA) to fabricate organic bistable devices (OBDs). The devices utilize spin coated polymer nanocomopsite thin film, which exhibit electrical bistability and WORM characteristics in switching between high conductive (ON) and low conductive (OFF) states and it has been observed that along with ZnO nanorod concentration, oxygen vacancy content is also an important factor for the achievement of ON-OFF conductive states. The maximum ON/OFF current ratio is of the order of 5×103 for Al/ZnO nanorods:PMMA/ITO heterostructures with 0.5wt% of ZnO nanorods. Statistical results indicate that the operating stability of devices with high retention time of 103s. We demonstrate that the enhancement of memory parameters are controlled by the oxygen vacancies existed in the engineered ZnO nanorods. These native defects are credited as basis of resistive switching behaviour of the devices. By comparing the C–V curves to the current–voltage (I–V) curves, dielectric constant, electron mobility and oxide trap densities have been estimated.