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

Abstract

Porphyrin units are a kind of ideal electron donor units, which have large π conjugation and well-defined planar and electron-rich structures. The inserted alkynyl π bridges between porphyrin units and anhydride moieties can effectively enlarge the π-electron delocalization and molecular dimension effect and thus enhance the electron-donating ability and reduce the dipole moment in the porphyrin-based hyperbranched polyimides (HBPIs). The synergy effect of porphyrin units and alkynyl π bridges can facilitate the charge-transfer formation and dissociation, realize the transformation of memory type, and shorten the retention time of HBPI-TAPEPP-6FDA-based memory devices. The HBPI-TAPEPP-6FDA-based memory devices manifest lower threshold voltages of −2.32 and 2.42 V, a higher ON/OFF current ratio up to 10 7 , and a shorter retention time of ∼20 s.

Crosslinked porous polyimides: structure, properties and applications

“…36 It is to be noted that we are only considering conjugated pPI networks in this section owing to their attractive electronic properties. The electronic properties of non-conjugated pPIs are explored in two recent publications by Tian et al, 64 and Gao et al, highlighting attempts to increase conductivity focusing on increasing pPI conjugation, or via addition of conjugated additives.…”

Hyperbranched polyimide with triazole core structure for nonvolatile resistive switching memory

“…21 Among the polyimides, functional HBPIs have attracted more and more attention because of their unique isotropic globular structure. 22,23 On the one hand, similar to linear PIs, HBPIs also possess excellent comprehensive performance, such as outstanding thermal properties, chemical resistance, and great photoelectric properties. 24,25 On the other hand, the unique isotropic globular structures endow HBPIs with good solubility and low viscosity in common solvents, which are beneficial to solution processing.…”

Novel Hyperbranched Polyimides Bearing Bis(trifluoromethyl)‐triphenylamine Moiety: Preparation and Rewritable Nonvolatile Memory Behaviours

“…Our group has carried out some work focusing on hyperbranched polyimides (HBPIs) memory materials [19–24] . HBPIs usually exhibit good solubility, processability and rich structural flexibility on account of their three‐dimensional dendritic structure [25–27] .…”