Nonvolatile memory devices based on electrical conductance tuning in poly(N-vinylcarbazole)-graphene composites

Nonvolatile memory devices, based on electrical conductance tuning in thin films of poly(N-vinylcarbazole) (PVK)-graphene composites, are fabricated. The current density-voltage characteristics of the fabricated device show different electrical conductance behaviors, such as insulator behavior, write-once read-many-times (WORM) memory effect, rewritable memory effect and conductor behavior, which depend on the content of graphene in the PVK-graphene composites. The OFF and ON states of the WORM and rewritable memory devices are stable under a constant voltage stress or a continuous pulse voltage stress at a read voltage of -1.0 V. The memory mechanism is deduced from the modeling of the nature of currents in both states in the devices. (C) 2012 Elsevier B.V. All rights reserved.