Enhancements of the memory margin and the stability of an organic bistable device due to a graphene oxide:mica nanocomposite sandwiched between two polymer (9-vinylcarbazole) buffer layers

Abstract

Current-voltage (I-V) curves for the Al/polymer (9-vinylcarbazole) (PVK)/graphene oxide (GO):mica/PVK/indium-tin oxide (ITO) devices at 300K showed a current bistability with a maximum high conductivity (ON)/low conductivity (OFF) ratio of 2 x 10(4), which was approximately 10 times larger than that of the device without a PVK layer. The endurance number of ON/OFF switchings for the Al/PVK/GO:mica/PVK/ITO device was 1 x 10(2) cycles, which was 20 times larger than that for the Al/GO:mica/ITO device. The "erase" voltages were distributed between 2.3 and 3V, and the "write" voltages were distributed between -1.2 and -0.5 V. The retention time for the Al/PVK/GO:mica/PVK/ITO device was above 1 x 10(4) s, indicative of the memory stability of the device. The carrier transport mechanisms occurring in the Al/PVK/GO:mica/PVK/ITO and the Al/GO:mica/ITO devices are described on the basis of the I-V results and the energy band diagrams. (C) 2017 Elsevier B.V. All rights reserved.