Tunable memory performances of the porphyrin terminated hyperbranched polyimides

Abstract

Herein, a functional hyperbranched polyimide, denoted as ATPP-HBPI, was synthesized by termination of polyamic acid with 5-(4-aminophenyl)-10, 15, 20-triphenylporphyrin (ATPP) and chemical imidization. Subsequently, ATPP-HBPI was coordinated with Zn ion to give Zn-ATPP-HBPI. In the HBPIs, the porphyrin terminals acted as the electron donor (D) and the 6FDA moieties acted as the electron acceptor (A) to promote the electron transition. Both ATPP-HBPI and Zn-ATPP-HBPI exhibited good organo-solubility and high thermal stability. They were used as the electroactive layer to fabricate the memory device with a configuration of indium tin oxide (ITO)/HBPI/Al to evaluate their bistability. The devices exhibited different memory behaviors, WORM for ATPP-HBPI and SRAM for Zn-ATPP-HBPI, respectively. Optical and electrochemical experiments and molecular simulation were carried out to illustrate this phenomenon of performance transformation. The results show that the metallization of terminal of the HBPIs provides a strategy for tailoring the memory characteristics of the devices. V C 2018 Wiley Periodicals, Inc. J. ory characteristics of the devices.

Synergy Effect of Porphyrin Units and Alkynyl π Bridges Tunes the Memory Behavior and Threshold Voltage of Hyperbranched Polyimides

“…The maximum emission wavelength was at ∼656 nm both for HBPI-TAPP-6FDA and HBPI-TAPEPP-6FDA, indicating the similar E g values, and the results were consistent with the UV−vis spectra. 32,33 In addition, the introduced alkynyl π bridge improved the electron-donating ability. The onset oxidation potential (E ox (onset)) significantly reduced to 0.58 V of HBPI-TAPEPP-6FDA in the CV measurement (Figure 4c), meaning that it was easier to donate electrons.…”