title: Direct observation of enhanced cathodoluminescence emissions from ZnO nanocones compared with ZnO nanowire arrays.
abstract: We report, for the first time, direct observation of enhanced cathodoluminescence (CL) emissions from ZnO nanocones (NCs) compared with ZnO nanowires (NWs). For direct and unambiguous comparison of CL emissions from NWs and nanocones, periodic arrays of ZnO NW were converted to nanocone arrays by our unique HCl [aq] etching technique, enabling us to compare the CL emissions from original NWs and final nanocones at the same location. CL measurements on NW and nanocone arrays reveal that emission intensity of the nanocone at ∼ 387 nm is over two times larger than that of NW arrays. The enhancement of CL emission from nanocones has been confirmed by finite-difference time-domain simulation of enhanced light extraction from ZnO nanocones compared to ZnO NWs. The enhanced CL from nanocones is attributed to its sharp morphology, resulting in more chances of photons to be extracted at the interface between ZnO and air.
authors.affiliation: School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0245, USA.
authors.forename: Joonho
authors.initials: J
authors.lastname: Bae
authors.forename: Ee Le
authors.initials: EL
authors.lastname: Shim
authors.forename: Yeonsang
authors.initials: Y
authors.lastname: Park
authors.forename: Hyunjin
authors.initials: H
authors.lastname: Kim
authors.forename: Jong Min
authors.initials: JM
authors.lastname: Kim
authors.forename: C J
authors.initials: CJ
authors.lastname: Kang
authors.forename: Y J
authors.initials: YJ
authors.lastname: Choi