Tuning the Electronic Properties of Benzimidazoles via D‐A‐D/A Functionalization for Enhanced Organic Resistive Memory Performance

The donor‐acceptor system is vital, with benzimidazole emerging as a notable acceptor for memory devices. In this work, a new benzimidazole‐linked benzothiophene was synthesized via Pd‐catalyzed Suzuki cross‐coupling, featuring D‐A‐D and D‐A‐A compounds. UV–vis analysis indicated strong intramolecular interactions and a band gap of 3.12–3.25 eV, suggesting advantageous charge transport properties for memory applications. SEM and thin‐film XRD confirmed improved molecular ordering, substrate coverage, and high crystallinity in the thin films. Non‐volatile binary WORM memory behavior was exhibited by the synthesized compounds. The methoxy‐substituted compound showed effective memory performance with a low threshold voltage (−1.08 V) and an ON/OFF ratio of 10 3 , while the dibenzofuran‐substituted compound exhibited a higher ON/OFF ratio of 10 4 and a threshold voltage of −2.62 V. D‐A‐based compounds with varying substituents demonstrated favorable retention time (10 3 s) and endurance up to 100 cycles. The observed resistive switching mechanism results from both charge trapping and charge transfer effects. This study underscores the significant impact of substituent alterations in D‐A molecules on molecular arrangement, electron trap depth, and thin film morphology, and all of which significantly influence memory performance in organic devices.