title: ZnO nanotips and nanorods on carbon nanotube/Si substrates: anomalous p-type like optical properties of undoped ZnO nanotips.
abstract: ZnO nanotips and nanorods were grown on screen-printed multi-walled carbon nanotube (MWCNT) films via thermal chemical vapor deposition at relative low growth temperatures of 400 and 500 °C. Uniform formation of ZnO nanotips and nanorods occurred on MWCNT-printed Si substrates, but were rarely observed on bare Si substrates at the same growth temperatures. In photoluminescence (PL) measurements, it was found that ZnO nanorods exhibit typical intrinsic optical properties, while ZnO nanotips revealed p-type like luminescence behavior. Acceptor-related emission bands originating from neutral acceptor-bound exciton, free-to-acceptor and donor-acceptor pair transitions are clearly observed in temperature-dependent PL spectra of ZnO nanotips.
authors.affiliation: School of Advanced Materials and System Engineering, Kumoh National Institute of Technology, Gumi, Gyeongbuk 730-701, Korea.
authors.forename: Seung-Sik
authors.initials: SS
authors.lastname: Park
authors.forename: Jin-Moo
authors.initials: JM
authors.lastname: Lee
authors.forename: Sung-Jin
authors.initials: SJ
authors.lastname: Kim
authors.forename: Sang-Woo
authors.initials: SW
authors.lastname: Kim
authors.forename: Min-Su
authors.initials: MS
authors.lastname: Yi
authors.forename: Sang-Hyeob
authors.initials: SH
authors.lastname: Kim
authors.forename: Sunglyul
authors.initials: S
authors.lastname: Maeng
authors.forename: Shizuo
authors.initials: S
authors.lastname: Fujita