Outstanding flexibility of organic memory devices with transparent graphene top electrodes

The organic memory device was fabricated 8 × 8 cross-bar array-type with transparent graphene electrodes on a poly(ethylene terephthalate) (PET) substrate. The active layer of the memory devices is a composite of polyimide and 6-phenyl-C61 butyric acid methyl ester (PCBM). The sheet resistance of the graphene film on memory device was found to be ∼270Ω/□, and the transmittance of separated graphene film from memory device was ∼92 %. The memory devices showed typical write-once-read-many (WORM) characteristics and an ON/OFF ratio of over ∼10⁶. The memory devices also exhibited outstanding cell-to-cell uniformity with flexibility. There was no substantial variation observed in the current levels of the WORM memory devices upon bending and bending cycling up to 10,000 times. A retention time of over 10⁴ sec was observed without fluctuation under bending.