Improving memory performance of PVA:ZnO nanocomposite: The experimental and theoretical approaches

Abstract

The interactions between organic and inorganic components of nanocomposites plays a key role in their microstructure and optoelectrical properties. The comprehensive understanding of these interactions can promote various potential applications of materials, especially in the field of electronic memory devices. In this study, we investigate the interactions of polyvinyl alcohol (PVA) and oxygen vacancy-rich ZnO nanoparticles (NPs) and resistive switching effect of PVA:ZnO nanocomposite. The density functional theory calculation indicates that the PVA chemisorption and the oxygen vacancies of ZnO play a key role in strongly reducing the work function of ZnO NPs of which conduction band can act as a bottom of potential well for trapping electrons in the PVA:ZnO nanocomposite. The oxygen vacancies also increase the stability of the potential well by enhancing chemical bonding between PVA and ZnO. Moreover, we show that at a specific content of ZnO NPs in the PVA matrix, the Ag/PVA:ZnO/FTO memory device has the best resistive switching behavior (operating voltage < 1 V). This implies there exists an optimal average width of the energy barriers between the ZnO NPs in the PVA matrix. The electrical transport mechanisms and resistive switching behavior of this device are also investigated in details.