Flexible Memristive Device Based on WSe2 Quantum Dots Sandwiched Between Two Poly (Methyl Methacrylate) Layers

In this letter, we demonstrate the fabrication of flexible memristive devices using tungsten di-selenide (WSe2) quantum dots (QDs) as the active layer. The WSe2 QDs were synthesized by facile two-step technique consisting of solvothermal and sonication processes to utilize the charge-trapping sites in the memristive devices. The sizes of as-synthesized WSe2 QDs, as determined from the transmission electron microscopy image, were in the range between 3 and 5 nm. Current-voltage(I-V) curves for the flexible memristive devices based on nanocomposites consisting of WSe2 QDs sandwiched between two poly (methyl methacrylate) (PMMA) layers showed remarkable bi-stable behavior before and after bending. The ON/OFF ratio of the memory devices before and after bending were approximately 1x10(2) and 1x10(2), respectively. The devices showed the nonvolatile memory effect with a retention time of more than 7 x 10(2)s. The endurance number of ON/OFF switching cycles for the devices was 1 x 10(2). The bipolar resistive switching behavior was described on the basis of the I-V results by analyzing the effect of space charge.