Nanostructure- and Orientation-Controlled Resistive Memory Behaviors of Carbohydrate-block-Polystyrene with Different Molecular Weights via Solvent Annealing.

We report the resistive electrical memory characteristics controlled by the self-assembled nanostructures of maltoheptaose-block-polystyrene (MH-b-PS) block copolymers, where the MH and PS blocks provide the charge-trapping and the insulating tunneling layer, respectively. A simple solvent annealing process, with various annealing conditions, were introduced for MH-b-PS thin films to achieve disordered, orientated cylinders and ordered-packed spheres morphologies. More details about the self-assembled MH-b-PS nanostructures, coupled with different volume fractions between MH and PS blocks, were investigated using atomic force microscopy and grazing-incidence small-angle X-ray scattering analyses. Moreover, various electrical memory behaviors including nonvolatile write-once-read-many-times (WORM) and Flash, and volatile dynamic-random-access-memory (DRAM) could be obtained by the same material (MH-b-PS3k). This study establishes a detailed relationship between the nanostructure of the MH-b-PS-based block copolymers and their memory behavior of the resistive memory devices.