A bismuth copper oxide nanoparticle-based memristor and a preparation method thereof

Abstract

A kind of bismuth copper oxide nanoparticle-based memristor and its preparation method, using room temperature solid phase grinding method, with copper nitrate, bismuth nitrate as raw material, sodium hydroxide as mineralizer, after mixing grinding, washing, vacuum drying, low-temperature annealing, the CuBi2O4 nanoparticle of high crystallinity, uniform morphology is prepared;By controlling annealing temperature, realize the optimal control of grain size, phase purity and micro morphology, determine about 400 DEG C as the preferred annealing condition.CuBi2O4 nanoparticle is used as functional layer, and the vertical structure memristor of conductive substrate / CuBi2O4 particle film / top electrode is constructed, based on the directional migration of oxygen vacancy, controllable conductive filament is formed, and stable resistance change memory and artificial synapse characteristics are realized.The nanoparticle process of the application is simple, environment-friendly and low-cost, the device has high on-off ratio, cycle stability and excellent consistency, and is suitable for flexible non-volatile memory, artificial synapse, storage and computing integrated chip and other scenes.

Claims

1. A memristor based on copper bismuthate oxide nanoparticles, characterized in that, From bottom to top, it consists of a conductive substrate, a CuBi2O4 nanoparticle functional layer and a top electrode. The CuBi2O4 nanoparticle functional layer is formed by stacking pure-phase tetragonal CuBi2O4 nanoparticles. The nanoparticles have a near-spherical or polyhedral morphology and a size of 15 nm to 150 nm. The CuBi2O4 nanoparticle functional layer achieves resistance changes through the switching of conductive filaments mediated by oxygen vacancy migration.

2. The memristor as claimed in claim 1, characterized in that, The pure-phase tetragonal CuBi2O4 nanoparticles were prepared by room-temperature solid-state grinding, including the following steps: Copper salt and bismuth salt will be weighed as raw materials according to the atomic ratio of Cu to Bi of 1:

2. Preliminary grinding and mixing are performed to ensure that the two raw material powders are evenly dispersed; Continue grinding, and during the continued grinding process, add excess sodium hydroxide solid in portions as a mineralizing agent. After adding the mineralizer, the grinding was continued to obtain a grayish-brown crude product of CuBi2O4 precursor. After washing and drying the crude precursor product, it was subjected to low-temperature annealing at 380℃~420℃ to obtain pure-phase tetragonal CuBi2O4 nanoparticles.

3. The memristor as described in claim 2, characterized in that, The annealing temperature for the low-temperature annealing is specifically 400°C, and the annealing time is 1 hour.

4. The memristor as described in claim 2, characterized in that, The copper salt and bismuth salt are Cu(NO3)2・3H2O and Bi(NO3)3・5H2O, respectively; the molar ratio of the copper salt, bismuth salt and excess sodium hydroxide solid is 1:2:

10.

5. The memristor as described in claim 4, characterized in that, The further grinding specifically includes: continuing grinding until the material being ground is completely dry to produce a grayish-brown CuBi2O4 precursor crude product.

6. The memristor as claimed in claim 2, characterized in that, The cleaning and drying process specifically includes: ultrasonically dispersing the crude precursor product in deionized water to dissolve soluble impurities in the water, then centrifuging it at 6000 r / min and discarding the supernatant to obtain the centrifuged product; repeating the ultrasonic dispersion, centrifugation, and discarding of the supernatant several times on the centrifuged product, and then drying it thoroughly at a constant temperature not exceeding 80°C.

7. The memristor as claimed in claim 1, characterized in that, The conductive substrate is specifically ITO conductive glass, FTO conductive glass, flexible PET-ITO substrate, PI-ITO substrate, or metal foil substrate.

8. The memristor as claimed in claim 1, characterized in that, The top electrode is specifically an inert metal or a conductive polymer; The top electrode is fixed on the CuBi2O4 nanoparticle functional layer by thermal evaporation, magnetron sputtering or printing, and a stable electrical circuit is formed between the top electrode and the CuBi2O4 functional layer.

9. The method for preparing a memristor based on copper bismuthate oxide nanoparticles as described in claim 1, characterized in that, Includes the following steps: Copper salt and bismuth salt were weighed as raw materials according to a Cu to Bi atomic ratio of 1:

2. Preliminary grinding and mixing are performed to ensure that the two raw material powders are evenly dispersed; Continue grinding, and during the continued grinding process, add excess sodium hydroxide solid in portions as a mineralizing agent. After adding the mineralizer, the grinding was continued to obtain a grayish-brown crude product of CuBi2O4 precursor. After washing and drying the crude precursor product, it was annealed at a low temperature of 300℃~500℃ to obtain pure phase tetragonal CuBi2O4 nanoparticles. The pure-phase tetragonal CuBi2O4 nanoparticles were dispersed in a dispersion medium, stirred evenly, and then coated onto the surface of a conductive substrate. A second low-temperature annealing treatment was performed to form a uniform and dense CuBi2O4 functional film, which served as the CuBi2O4 nanoparticle functional layer. A top electrode was fabricated on the functional layer of CuBi2O4 nanoparticles.

10. The method for preparing a memristor based on copper bismuthate oxide nanoparticles as described in claim 9, characterized in that, The second low-temperature annealing treatment was performed at a temperature of 400°C for 1 hour.

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