High Performance Organic Nonvolatile Flash Memory Transistors with High-Resolution Reduced Graphene Oxide Patterns as a Floating Gate

Abstract

High-performance organic nonvolatile memory transistors (ONVMTs) are demonstrated, the construction of which is based on novel integration of a highly conductive polymer as a semiconductor layer, hydroxyl-free polymer as a tunneling dielectric layer, and high-resolution reduced graphene oxide (rGO) patterns as a floating gate. Finely patterned rGO, with a line width of 20-120 mu m, was embedded between SiO2 and the polymer dielectric layer, which functions as a nearly isolated charge-trapping center. The resulting ONVMTs demonstrated ideal memory behavior, and the transfer characteristics promptly responded to writing and erasing the gate bias. In particular, the retention time of written/erased states tended to increase as the rGO line width was reduced, implying that the line width is a critical factor in suppressing charge release from rGO. Using a 20-mu m-wide rGO pattern, a nonvolatile large memory window (>20 V) was retained for more than 5 x 10(5) s, which is 50 times longer than non-patterned rGO films.