title: Structurally nanocrystalline-electrically single crystalline ZnO-reduced graphene oxide composites.
abstract: ZnO, a wide bandgap semiconductor, has attracted much attention due to its multifunctionality, such as transparent conducting oxide, light-emitting diode, photocatalyst, and so on. To improve its performances in the versatile applications, numerous hybrid strategies of ZnO with graphene have been attempted, and various synergistic effects have been achieved in the ZnO-graphene hybrid nanostructures. Here we report extraordinary charge transport behavior in Al-doped ZnO (AZO)-reduced graphene oxide (RGO) nanocomposites. Although the most challenging issue in semiconductor nanocomposites is their low mobilities, the AZO-RGO nanocomposites exhibit single crystal-like Hall mobility despite the large quantity of nanograin boundaries, which hinder the electron transport by the scattering with trapped charges. Because of the significantly weakened grain boundary barrier and the proper band alignment between the AZO and RGO, freely conducting electrons across the nanograin boundaries can be realized in the nanocomposites. This discovery of the structurally nanocrystalline-electrically single crystalline composite demonstrates a new route for enhancing the electrical properties in nanocomposites based on the hybrid strategy.
authors.affiliation: Department of Materials Science and Engineering, KAIST , Daejeon 305-701, Korea.
authors.forename: Woo Hyun
authors.initials: WH
authors.lastname: Nam
authors.forename: Bo Bae
authors.initials: BB
authors.lastname: Kim
authors.forename: Seul Gi
authors.initials: SG
authors.lastname: Seo
authors.forename: Young Soo
authors.initials: YS
authors.lastname: Lim
authors.forename: Jong-Young
authors.initials: JY
authors.lastname: Kim
authors.forename: Won-Seon
authors.initials: WS
authors.lastname: Seo
authors.forename: Won Kook
authors.initials: WK
authors.lastname: Choi
authors.forename: Hyung-Ho
authors.initials: HH
authors.lastname: Park
authors.forename: Jeong Yong
authors.initials: JY
authors.lastname: Lee
keywords: ZnO; charge transport; mobility; nanocomposite; reduced graphene oxide