Investigation On The Hybrid Resistance Switching Memory Devices Based On Nano ZnO

Due to its high switching speed and storage density, the inorganic/organic hybridresistance switching memory devices are considered to be the attractive potential in the nextgeneration non-volatile memory devices. However, the progress in this field is still in earlystages and the switch mechanisms such as influence of nano-material features and devicestructure on devices performance are in controversy. In this paper, the resistance switchingmechanism and carrier transport characteristic for the hybrid devices were discussed in theway of the surface modification of nanoparticles (NPs) and the reasonable design of thedevice structure.1The in situ growth of ZnO NPs was carried out in a three-dimensional SiO2networkwhich was formed by hydrolysis of TEOS. Hybrid resistance switching memory devices withthe structure of ITO/SiO2modified-ZnO NPs embedded in PVP/Al were prepared usingspin-casting method. The improved device performance was achieved with the additionalSiO2modification and was attributed to the electron loss suppression in ZnO NPs and thebarrier establish against the carrier release. The dispersion of ZnO NPs was also improved andcorrelated to a uniform film thickness. Based on the energy-band diagram, the resistanceswitching mechanism and the carrier trapping and de-trapping process of devices werediscussed.2ZnO nanorods were synthesized by the aqueous chemical growth method. Thephotoluminescence spectra for the ZnO nanorods before and after vacuum annealing showedthe different features, indicating the dominated oxygen vacancy and zinc vacancy in ZnOnanorods. Two hybrid memory devices with the structure of the FTO/ZnO NRs/PMMA/Alwere prepared. Compared the devices utilizing the ZnO nanorods by thermal annealing, theI-V curves of devices with as-grown ZnO nanorods showed better resistance switchingbehaviour. It was possible to owe this effect to the oxygen vacancy existing in ZnO nanorods.3An hybrid resistance switching memory device with the structure of ITO/PVP/ZnOnanocrystal (NCs)/PbS nanocrystal (NCs)/PVP/Al was fabricated. Compared with thereference devices, the target device displayed the increased ON/OFF ratio by2orders ofmagnitude. The mechanism was related to the modification of PbS NCs layer in term ofdevice structure and low surface recombination loss.