Synthesis Of Alternating Copolysiloxane With Terthiophene And Perylenediimide Derivative Pendants For Involatile Worm Memory Device

With the rapid development of the information age, the traditional information storage technology has failed to meet our needs, so the searchs for new storage technologies and materials have been imperative. As a kind of new emerging material, organic electrical memory materials have been extensively studied.Alternating copolysiloxane with both electron donor terthiophene and electron acceptor perylenediimide derivative pendants (PTSi-alt-PDISi) was synthesized successfully. What’s more, another two kinds of homopolymer (PDISi and PTSi) were also synthesized. The structures of polymer were confirmed by1NMR. PTSi-alt-PDISi showed excellent amorphous glass state stability and high thermal decomposition temperature by differential scanning calorrimety (DSC) and thermogravimetric analysis (TGA). The optical properties of PTSi-alt-PDISi were characterized by UV-Vis absorption spectra and PL spectra. We found that the absorption spectra of thin film had slight bathochromic shift comparing with the peaks in solution. Furthermore, the PTSi-alt-PDISi shows strong fluorescence quenching, indicating the efficient energy transfer from donor thiophene blocks to acceptor perylene bisimide blocks. The measured HOMO and LUMO energy levels of PTSi-alt-PDISi are-5.75and-3.54eV, respectively.The fabricated memory device with the configuration of ITO/PTSi-alt-PDISi/Au(Al) showed nonvolatile write once read many times (WORM) memory characteristics. Its turn-on threshold voltage was1.7V, while it’s ION/OFF current density ratio was around104in ambient atmosphere. The well-defined memory property of PTSi-alt-PDISi was attributed to the transition of the pendant terthiophene and perylenediimide groups from the disoriented state to the ordered face-to-face conformation at the threshold voltage and the charge transfer interaction between pendent terthiophene donor and perylenediimide acceptor moieties, which were confirmed by XRD patterns and fluorescence emission measurement. This suggested that the new donor-acceptor polysiloxanes have potential applications in the field of memory devices.