title: Nonvolatile memory device using gold nanoparticles covalently bound to reduced graphene oxide.
abstract: Nonvolatile memory devices using gold nanoparticles (AuNPs) and reduced graphene oxide (rGO) sheets were fabricated in both horizontal and vertical structures. The horizontal memory device, in which a singly and doubly overlayered semiconducting rGO channel was formed by simply using a spin-casting technique to connect two gold electrodes, was designed for understanding the origin of charging effects. AuNPs were chemically bound to the rGO channel through a π-conjugated molecular linker. The π-conjugated bifunctional molecular linker, 4-mercapto-benzenediazonium tetrafluoroborate (MBDT) salt, was newly synthesized and used as a molecular bridge to connect the AuNPs and rGOs. By using a self-assembly technique, the diazonium functional group of the MBDT molecular linker was spontaneously immobilized on the rGOs. Then, the monolayered AuNPs working as capacitors were covalently connected to the thiol groups of the MBDT molecules, which were attached to rGOs (AuNP-frGO). These covalent bonds were confirmed by XPS analyses. The current-voltage characteristics of both the horizontal and vertical AuNP-frGO memory devices showed noticeable nonlinear hysteresis, stable write-multiple read-erase-multiple read cycles over 1000 s, and a long retention time over 700 s. In addition, the vertical AuNP-frGO memory device showed a large current ON/OFF ratio and high stability.
authors.affiliation: Department of Chemistry, National Creative Research Initiative, Center for Smart Molecular Memory, Samsung-SKKU Graphene Center, Sungkyunkwan University, 300 Cheoncheon-Dong, Jangan-Gu, Suwon, Gyeonggi-Do 440-746, Republic of Korea.
authors.forename: Peng
authors.initials: P
authors.lastname: Cui
authors.forename: Sohyeon
authors.initials: S
authors.lastname: Seo
authors.forename: Junghyun
authors.initials: J
authors.lastname: Lee
authors.forename: Luyang
authors.initials: L
authors.lastname: Wang
authors.forename: Eunkyo
authors.initials: E
authors.lastname: Lee
authors.forename: Misook
authors.initials: M
authors.lastname: Min
authors.forename: Hyoyoung
authors.initials: H
authors.lastname: Lee