High-performance non-volatile transistor memory devices using charge-transfer supramolecular electrets

We demonstrated high performance non-volatile pentacene based OFET memory devices using charge transfer (CT) supramolecules of poly(4-vinylpyridine) (P4VP) with two different chromophores, 3-(dicyanomethylidene)indan-l-one (1CN-IN) and 1,3-bis(dicyanomethylidene)indan (2CN-IN), respectively. The intermolecular CT interaction effectively introduced the chromophores as charge trapping sites into the P4VP matrix, leading to a controllable flash-type memory behavior. The electron-trapping ability of the supramolecular electrets was increased with enhancing the chromophore composition in the supramolecules. The experimental molar ratio x of chromophores binding to the repeating unit of P4VP, however, was limited to 0.30 for P4VP(1CN-IN)(x), or 0.45 for P4VP(2CN-IN)(x). The 2CN-IN with one more electron-withdrawing dicyanomethylene group, compared to 1CN-IN, provided a better electron-trapping ability and thus obtained a larger memory window. The device based on P4VP(2CN-IN)(0.30) electret exhibited the largest memory window (79 V) with the excellent retention ability of up to 10(7)s and endurance of over 100 cycles. The study revealed that the CT supramolecular electret could be as a facile and simple approach for future organic memory device applications. (C) 2016 Elsevier B.V. All rights reserved.