Enhancing the Resistive Switching Behavior of WORM Memory Devices Using D−π−A Based Ester‐Flanked Quinolines**
Varghese Maria Angela, Deivendran Harshini, Anshika Anjali, Predhanekar Mohamed Imran, Nattamai S. P. Bhuvanesh, Samuthira Nagarajan
Abstract
Abstract Donor‐Acceptor systems are highly appreciated in the field of organic memory devices due to their efficient charge transport within the systems. In this work, we have designed and synthesized a D−π−A system constituting ester‐flanked quinolines and functionalized triarylamines (TAA) through a single‐step cross‐coupling reaction to fabricate memory devices via Write‐Once Read‐Many times (WORM) non‐volatile memory. Structure‐property relationships are reconnoitered for these conjugated D−π−A systems through a series of UV, fluorescence, XRD, DFT, and memory characterizations. The UV and CV data show efficient charge transfer with intramolecular charge transfer occurring at 407–417 nm and a short band gap of 2.56–2.65 eV. An enhancement in the resistive switching behavior of the memory devices is observed for the compounds with simple TAA‐quinoline and tert‐butylphenyl substituted TAA and fluorophenyl substituted quinoline due to balanced charge distribution in the compounds. This enhanced switching induces an on/off ratio of 10 3 by generating a highly ordered arrangement in the thin films. The HOMO, LUMO levels, and the ESP images together estimate a charge transfer and charge trapping as the plausible mechanism for the solution‐processable WORM memory devices. The longer retention time (10 3 s) and lower threshold voltages (−1.21–−2.12 V) of the devices makes them intriguing compounds for memory applications.