title: Electrical conductivity enhancement of metallic single-walled carbon nanotube networks by CoO decoration.
abstract: We report that the decoration of metallic single-walled carbon nanotube (m-SWCNT) networks with cobalt(ii) oxide (CoO) can improve the electrical conductivity of the networks. To measure the electrical conductivity, we prepared m-SWCNT networks between the source and drain electrodes of field-effect transistors (FETs). Then, the amount of CoO nanoparticles (NPs) used for decoration was controlled by treating the FETs with different volumes of a solution containing Co(NO3)2·6H2O. Atomic force microscopy imaging showed that CoO NPs were intensively deposited on the intertubular junction of the m-SWCNT networks. X-ray photoelectron spectroscopy confirmed that the oxidation state of the Co element on m-SWCNT was CoO. Raman spectra revealed that heavy decoration of CoO increased the D-band intensity of the m-SWCNT, indicating that the CoO NPs disordered the sp(2) hybridized carbon atoms of the m-SWCNT via decoration. The electrical conductivity of the m-SWCNT networks was enhanced up to 28 times after decoration, and this was attributed to the CoO NPs connecting the m-SWCNTs at junctions of the networks.
authors.affiliation: School of Electrical Engineering, Korea University, Anam-dong, Seongbuk-gu, Seoul 136-713, Korea. nanotube@korea.ac.kr.
authors.forename: Do-Hyun
authors.initials: DH
authors.lastname: Kim
authors.forename: Sang Yun
authors.initials: SY
authors.lastname: Lee
authors.forename: Jun Eon
authors.initials: JE
authors.lastname: Jin
authors.forename: Gyu Tae
authors.initials: GT
authors.lastname: Kim
authors.forename: Dong-Jin
authors.initials: DJ
authors.lastname: Lee