Synthesis Of Charge Transfer Complexes And Study Of Their Electric Bistale Performance

Inorganic semiconductor can read or write information rapidly. However, because of the limit of high cost or low data storage density, it can not catch up with the development of memory device. Recent years polymer resistor-type memory device have got more and more attention, having great potential in information storage field.Confirmed by 1H-NMR, homopolymers (PCzPhSi, PCzMSi and PDI-PDI) and alternating copolysiloxane with both electron acceptor perylenediimide derivative and electron donor carbazole (PDI-Cz-Ph and PDI-Cz-M) was synthesized successfully. Memory device with the structure of Al|polymer thin film|ITO was prepared with five kinds of polymer and PCzPhSi/PDI-PDI, PCzMSi/PDI-PDI as the active layer. The devices exhibit rewritable memory behavior with high ON/OFF current ratio and threshold voltage of Ⅳ. Egap of polymers is calculated and characteristic absorption can be observed via UV-Vis spectra. PDI-Cz-Ph and PDI-Cz-M exhibit strong fluorescence quenching phenomenon in fluorescence emission spectra in both CH2C12 solution and film state which proves charge transfer happened between carbazole functional groups and perylenediimide derivative groups. HOMO and LUMO of polymers were calculated by Cyclic Voltammetry. Gaussian Simulation shows the small dipole difference of PDI-Cz-Ph and PDI-Cz-M, which results in that the CT complexes are unstable. When a reverse voltage is applied, CT complexes decompose, which accounts for the devices based on Al|PDI-Cz-Ph or PDI-Cz-M|ITO act as flash memory device.On the other hand, the synthetic water soluble perylenediimide derivative and GO prepared by Hummers method were blended, the UV-vis spectra shows the absorption of compounds increases when a little amount of GO was added. However, the absorption decreases with the content of GO. What’s more, fluorescence emission spectra exhibit similar rules. Fluorescence quenching indicates electron transfers from GO to PBI. Under the external force induced, oriented films of GO/PBI compounds were successfully obtained. Current-voltage (I-V) characteristics of the ITO|thin GO/PBI compounds layer|Au sandwich device with an initial positive voltage sweep indicates the electrical conductivity increases unobviously. After that, compared with the last positive voltage sweep, current in low conductivity state decreases. This phenomenon reason may be explain by that the applied voltage cause the polymer thin film’s degree of orientation declines.