| Summary: | 碩士 === 國立清華大學 === 化學系 === 98 === In this thesis we describe a nonvolatile memory device based on the introduction of silver/ poly(aniline-co-butylthioaniline) (Ag/Pani-SBu) core/shell nanoparticles (NPs) as the active layer. About the deposition of the nanoparticles, we have already tried both of the spin-coating and drop-casting fabrication method. In spin-coating method, we find the device will switch from off-state to on-state as the applying voltage is beyond the threshold voltage, and it can be turned off by applying opposite voltage. Besides, the ON/OFF current ratio increases as the concentration of NPs in the device increases. In drop-casting method, we use polyvinylpyrrolidone(PVP) as a top-cast buffer layer to reduce the roughness between NPs layer and cathode(Al), as illustrated experimental of devices D1 to D4. On the other hand, we also discuss whether the thickness of dielectric layer between NPs influences the threshold voltage of the device by mixing PVP polymer into NPs layer. The result indicated that as the addition amount of PVP increased, the threshold voltage of the device became higher. Furthermore, we use X-ray photoelectron spectroscopy (XPS) to analyze and investigate the possible resistance-switching mechanism. The result shows that, during the switching-on stage, the Pani-SBu shell is more positively charged while the Ag core is more negatively charged. This XPS result suggests the resistance-switching mechanism of the device is donor-acceptor charge transfer.
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