Study On Interface Of Inkjet Printed Electrode And 2D H-BN And Application In Memristor

The atomic-level thickness structural characteristics and excellent physical properties such as high electrical conductivity,high transparency,and flexibility of 2D materials make them a bright prospect for fabricating electronic devices.However,there are still great challenges to integrate 2D materials into commercial chips and circuits.This is because the structure of 2D materials may be damaged during fabrication and processing,resulting in degraded performance.Recent studies have shown that conventional metal deposition techniques(e.g.,electron beam vapor deposition)can severely damage the structure of 2D materials.To address these problems,this work uses inkjet printing technology to deposit metals on the surface of ultrathin two-dimensional material hexagonal boron nitride(h-BN),which avoids the damage to the atomic structure of h-BN and allows it to maintain a good interface,and memristor based on inkjet-printed electrodes demonstrates good performance.In this thesis,we first investigate the effects of deposition methods such as electron beam deposition,sputtering and inkjet printing on the interfaces and internal structure of2 D h-BN.The transmission electron microscopy images of the samples are analyzed,and it is found that electron beam deposition and sputtering distorted the upper and lower interfaces and internal structure of the h-BN,while the atomic structure of the ultrathin2 D h-BN is not significantly changed by the metal deposited using inkjet printing.From the X-ray energy dispersion spectrum,the distribution of nitrogen elements of the 2D hBN protected by inkjet-printed electrodes is uniform and continuous,and the boron element and nitrogen element curves in the electron energy loss spectrum are symmetric and overlapping.As a comparison,the distribution of nitrogen elements in the X-ray energy dispersion spectrum of 2D h-BN which is affected by electron beam deposited and sputtered metals is uneven,discontinuous and smaller in extent,and the changes in the boron and nitrogen curves in the electron energy loss spectrum show that 2D h-BN becomes thinner.To address the phenomenon that electron beam deposition and sputtering are more likely to damage the interface between 2D boron nitride and adjacent materials rather than the internal atomic structure of h-BN,the energy required for a gold atom to enter 2D h-BN is calculated using First Principle,and the results show that a gold atom needs at least 14 e V to penetrate into 2D h-BN without defects,while only 6 e V is required to penetrate into amorphous boron nitride.On the basis of the fact that inkjet-printed electrodes can effectively protect the interfaces of 2D boron nitride,we further prepared a memristor based on inkjet-printed electrode and conducted a comparative study of device performance with that based on electron beam deposited electrodes.The results of this paper show that the leakage current across the inkjet-printed electrode-based memristor is two orders of magnitude smaller than those of the memristor with electron-beam evaporated electrodes,which means lower power consumption.Also,the memristor based on inkjet-printed electrode requires a higher breakdown voltage to achieve resistive switching,which indicates a stronger reliability of the memristor.In addition,at a bias voltage of 0.07 V,the memristor based on inkjet-printed electrodes can transform randomly between two current states,showing the potential of application as an entropy source for true random noise generators.The results of this paper are important for a deeper understanding of inkjet printing technology and its application to two-dimensional materials,which can help to better design and optimize electronic devices and circuits.