Frist Principles Research On Memristor Based On Self Assembly Phosphonic Acid Monolayers

The advent of the big data era has put forward higher requirements on the storage capacity and operating speed of memory chips.Traditional computers based on the Von Neumann architecture face multiple challenges.Memristor has ultra-high storage density and extremely fast response speeds,which have unique advantages in areas such as computer storage-calculation and neural network simulation.However,the stability and biocompatibility of mainstream memristors are not good enough.Self assembly monolayers can effectively enhance the stability of the functional materials while having high biocompatibility.It is theoretically the most ideal memristor functional modification material.But no one has systematically explored the feasibility of using self-assembled molecules in the field of memristors as so far.Based on the first-principles,this paper discusses several aspects of memristor based on selfassembled phosphonic acid monolayers.In Chapter 3,20 kinds of phosphonic acid molecules with different alkyl chain lengths and functional end groups are established.The energy and polarity of the phosphonic acid molecules are discussed.We find that both the alkyl chain length and the functional group can significantly affect the electrical properties of the phosphonic acid molecule.The fourth chapter discusses the effect of phosphonic acid molecules on inert electrode memristors.It is found that phosphonic acid molecules are adsorbed on the surface of the memristor functional layer material by hydrogen bonding or chemical bonding,and the binding energy was positive after adsorption,indicating that the phosphonic acid molecules can enhance the stability of the memristor.At the same time,we also find that the 20 kinds of phosphonic acid molecules can significantly reduce the interface barrier of the memristor by a method similar to metal-semiconductor contact,which can reach-0.91 e V at most.The fifth chapter of this thesis compares and discusses the effect of phosphonic acid molecules on active electrode memristors.It is found that the combination of phosphonic acid molecules and memristors is different from inert electrode memristors due to the difference in electrode activity.At the same time,we also found that the phosphonic acid molecule also has a regulating effect on the interface barrier of the active electrode memristor.However,due to the pinning effect caused by the high state density of the active electrode surface,the regulating effect of the potential barrier is not as obvious as that of the inert electrode,and can only reach-0.3 e V at most.These works have certain guiding significance for the application of self assembly phosphonic acid monolayers in the field of memristor.