title: Electron field emission enhancement of vertically aligned ultrananocrystalline diamond-coated ZnO core-shell heterostructured nanorods.
abstract: Enhanced electron field emission (EFE) behavior of a core-shell heterostructure, where ZnO nanorods (ZNRs) form the core and ultrananocrystalline diamond needles (UNCDNs) form the shell, is reported. EFE properties of ZNR-UNCDN core-shell heterostructures show a high emission current density of 5.5 mA cm(-2) at an applied field of 4.25 V μm(-1) , and a low turn-on field of 2.08 V μm(-1) compared to the 1.67 mA cm(-2) emission current density (at an applied field of 28.7 V μm(-1) ) and 16.6 V μm(-1) turn-on field for bare ZNRs. Such an enhancement in the field emission originates from the unique materials combination, resulting in good electron transport from ZNRs to UNCDNs and efficient field emission of electrons from the UNCDNs. The potential application of these materials is demonstrated by the plasma illumination measurements that lowering the threshold voltage by 160 V confirms the role of ZNR-UNCDN core-shell heterostructures in the enhancement of electron emission.
authors.affiliation: Department of Materials Science and Engineering, National Tsing Hua University, Hsin-Chu, Taiwan 300, Republic of China.
authors.forename: Kamatchi Jothiramalingam
authors.initials: KJ
authors.lastname: Sankaran
authors.forename: Manekkathodi
authors.initials: M
authors.lastname: Afsal
authors.forename: Shiu-Cheng
authors.initials: SC
authors.lastname: Lou
authors.forename: Huang-Chin
authors.initials: HC
authors.lastname: Chen
authors.forename: Chulung
authors.initials: C
authors.lastname: Chen
authors.forename: Chi-Young
authors.initials: CY
authors.lastname: Lee
authors.forename: Lih-Juann
authors.initials: LJ
authors.lastname: Chen
authors.forename: Nyan-Hwa
authors.initials: NH
authors.lastname: Tai
authors.forename: I-Nan
authors.initials: IN
authors.lastname: Lin
mesh_terms: D003460:Crystallization; D008422:Materials Testing; D043942:Nanotubes / Q000737:chemistry*; D013499:Surface Properties; D015034:Zinc Oxide / Q000737:chemistry*
chemical_list: D015034:Zinc Oxide
keywords: ZnO nanorods; core-shell heterostructures; electron field emission; graphite layer; plasma illumination; ultrananocrystalline diamond needles