Electroforming-free flexible organic resistive random access memory based on a nanocomposite of poly(3-hexylthiophene-2,5-diyl) and orange dye with a low threshold voltage

Abstract

The charge trapping characteristics of an organic nanocomposite based on two polymers, poly(3-hexylthiophene-2,5-diyl) (P3HT) and orange dye (OD), were investigated by fabricating a sandwiched structure on a flexible polyethylene terephthalate substrate. The fabricated flexible organic device with a configuration of silver (Ag)/P3HT–OD/Ag displayed highly stable results consistent with a bipolar non-volatile resistive random access memory (RRAM) device using simple and controllable fabrication technology. It was observed that by the addition of OD, low threshold voltages (V th) of V set = 1.5 V and V reset = −1.5 V were achieved owing to the values of work function and energy bandgap of the materials used. Electrical rewritable effects of the fabricated memory device were tested for 102 voltage sweeps and 104s without any considerable degradation of its bistable resistive states. The switching mechanism was considered to be space charge limited current and this was verified by plotting the double logarithmic I–V curve. This is the first RRAM device based on P3HT polymer whose mechanical robustness has been tested for its mechanical robustness by bending it for 25 bending cycles at a bending diameter ranging from 15 cm to 5 cm without any considerable change in its properties. This finding offers important guidelines for reproducing next-generation flexible organic nanocomposite-based memory devices that are simple to fabricate and have low operating voltages and highly stable memory behavior.