Organic Resistive Random Access Memory Based On Gold Nanorods

The way of storing information by human beings ranges from ancient cave murals to paper books to modern binary system which can save words,sounds,pictures and so on.However,in the new era of information explosion,Internet of things,rising of wearable electronic products and etc,electronic memory is facing challenges of increasing storage capacity and transforming to flexibility and lightness and so on.Resistive random access memory(RRAM)is considered as the best choice to meet the “challenge” because it owns merits of high compatibility with current semiconductor technology,simple structure of metal-insulator-meta l(MIM),nanoscale size,analog behaviors,high density and low energy consumption.The device studied here is based on this kind of resistive memory.In addition,for realizing flexible and portable device,gold nanorods(Au NRs)mixed in polyvinylpyrrolidone(PVPy)solution were acted as device's active layer.Spherical gold nanoparticles(Au NPs)have been widely studied in memory,but the application of Au nanorods in memory is still in the preliminary stage of exploration.Further more,because of the bar-shape and anisotropy of gold nanorods that gave them advantages to form network structure and form ion channels in device,and gold nanorod has two local surface plasmon resonance peaks(LSPR)that mades it easy to convert from light to heat.Thus it is meaningful to study Au NRs doped organic resistive memory in this paper.In the process of experimental investigation,gold nanorods were synthesized by seed method and then were mixed with PVPy organic solution with different concentrations,later,using spin coating and evaporation methods to fabricate device.Meanwhile,various characterization methods were used to analyze morphology and structure of samples.Finally,from the test and analysis of the electrical performance of the devices,we get the following results as showed below:1.Devices doped with gold nanorods at 0.075mg/m L?0.15mg/m L?1.00mg/m L?2.00mg/m L and 4.00mg/m L all have swithing effect of positive turn-on and negative turn-off.The 2.00mg/m L gold nanoparticles doped device was choosed to investigate the conductive mechanism,and results showed that the resistivity of these devices is dominated by the conduction mechanism of the space-constrained conduction model(SCLC).2.The device doped with 6mg/mL gold nanorods has the phenomenon of volatile memory.After processing,fitting and analysising of the test data,it is concluded that this phenomenon is the combined action of the space-constrained conductive model and the conductive filament model.3.To devices with 2mg/mL Au NRs doped ITO/Au NRs-PVPy/Ag structure,excellent resistance switching performances of 50 times' repeatable switches have been measured.The device obeyed SCLC conductive mechanism in high resistance state,but the switching characteristics of the device were caused by disconnection and re-connection of Ag conductive filament.