| Nowadays, the rapid growth of economic development in society, the information explosion with the traditional device based on Moore’s law will have its theoretical storage capacity limit. The design and synthesis of new high density data storage storage material and semiconductor device has an extremely important significance. Based on the memory of the conjugated organic small molecule material has the advantages of low cost, easy to purify, easy processing, quick response, low power consumption advantages, is considered to be a kind of new memory material with wide application prospect. And in recent years conjugated organic small molecule material has made prominent progress, but in how to further improve the response speed and read and write cycles, switch, device maintain time and storage density has a lot of work needs to be done. Therefore, the design and preparation of good storage properties of novel small organic molecules and exploring the mechanism of storage storage materials has become a hot topic in the field of ultra high density data storage. Based on this, this paper carried out the design of a series of novel conjugated azo containing organic small molecular compounds, research synthesis and storage performance of the device, and the following research results were obtained.:(1) Investigation of Regioisomerism Effects on Multilevel States of a High Performance Organic Molecular Memory: In this chapter, we investigated structure-property relationships of a series of positional isomers, with an emphasis on the understanding of intermolecular interactions and their effects on the conduction process. Such positional-isomers have displayed similar intrinsic electronic properties(the same charge traps) but substantially different(binary or ternary) memory behaviours. Corresponding attenuated total reflection infrared(ATR-IR) studies have shed light on the inherent differences of different molecular interactions before and after applied bias. Our mechanistic investigations suggest that the denser π-π stacking is responsible for a distinct induced intermolecular electric field under bias, which plays a pivotal role in “filling†the charge traps in a stepwise fashion to generate three stable conductivity states. These findings provide a keen insight to the multilevel memory behaviours and offer an exciting opportunity for rational design of novel memory devices.(2) Investigation of the Symmetry and Polarity on multilevel device data storage performance: In this chapter, Three O-fluoroazobenzene-based molecules were chosen as memory-active molecules: FAZO-1 with a D--A2--D symmetric structure, FAZO-2 with an A1--A2--A1 symmetric structure, and FAZO-3 with a D--A2--A1 asymmetric structure. Both FAZO-1 and FAZO-2 had a lower molecular polarity, whereas FAZO-3 had a higher polarity. The fabricated indium--tin oxide(ITO)/FAZO-1/Al(Au) and ITO/FAZO-2/Al(Au) memory devices both exhibited volatile static random access memory(SRAM) behavior, whereas the ITO/FAZO-3/Al(Au) device showed nonvolatile ternary write-once-read-many-times(WORM) behavior. It should be noted that the reproducibility of these devices was considerably high, which is significant for practical application in memory devices. In addition, the different memory performances of the three active materials were determined to be attributable to the stability of electric-field-induced charge-transfer complexes. Therefore, the switching memory behavior could be tuned by adjusting the molecular polarity.(3) Investigation of effect of salification on data storage performance: In this chapter, we report the synthesis of a new organic conjugate molecule, 3-(4-((4-(dimethylamino)phenyl)diazenyl)phenyl)-1-(pyridin-4-yl)prop-2-en-1-one(AZOCP), and its camphorsulfonic acid salt(AZOCP-CSA). The photophysical and electrochemical characterization reveals that an enhanced π-π conjugation is formed in the camphorsulfonic acid salt because of the salification effect. The salification reaction also play an important role in the formation of a more ordered stacking nanocrystalline film as evidenced by AFM and XRD analysis, and thus gives rise to an improved transport of charge carriers. The comparison of device performance demonstrates that the device based on the use of the salificated compound has better resistive memory behaviour in terms of ON/OFF ratio, retention time and rewritable cycle. Isothermal I-V correction and theoretic calculation confirm that the resistive performance is a result of an electric-field-induced charge transfer effect and the enhanced device performance of camphorsulfonic acid salt is due to the presence of a strong salification-induced charge transfer effect. Our experimental finding suggests that the simple but effective salification strategy may find widespread use in promoting performance of other organic resistive memory devices by introducing a strong charge transfer effect.(4) Investigation of the phenazine-π-triphenylamine derivatives on memory device performance: The fluorine substituted azobenzene-π-triphenylamine derivatives: TM-1 and TM-2, and fluorine substituted phenazine-π-triphenylamine derivatives TM-3 were synthesized. The photophysical, electrochemical properties and memory behaviors of these donor-π-acceptor molecules were comparatively investigated. This comparative study of tuning the properties of conjugated D-A-D molecules via aromatic acceptor may be an alternative approach for the design and study of future high-performance memory devices based on new materials.In this paper, we study the factors that affect the memory performance by modifying the azobenzene skeleton of different methods, and discuss the method of improving the memory performance. In addition, puts forward the problems that can be further studied in the future and carry on an outlook of the future study in this realm.
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