title: ZnO nanorods with two spatially distinct light emissions.
abstract: Single-crystalline ZnO nanorods emitting two characteristic optical emissions from opposite halves of the nanorods were synthesized by thermal chemical vapor deposition using Zn/Al mixed powders. Energy dispersive x-ray spectra with transmission electron microscopy show a gradually decreasing Zn:O atomic ratio from the root to the top of a nanorod, and the averaged ratios at the two ends are ≈57.2:42.8 and 49.5:50.5. Room-temperature cathodoluminescence measurements show that the nanorods exhibit a sharp ultraviolet emission at 377 nm from one segment and a broad green band at 500 nm from the other, which is attributed to different oxygen concentrations along the nanorods. The luminescence behavior suggests further applications for nano-pixel optoelectric devices.
authors.affiliation: Department of Materials Science and Engineering, National Cheng Kung University, Tainan 70101, Taiwan.
authors.forename: Chien-Lin
authors.initials: CL
authors.lastname: Kuo
authors.forename: Ruey-Chi
authors.initials: RC
authors.lastname: Wang
authors.forename: Jow-Lay
authors.initials: JL
authors.lastname: Huang
authors.forename: Chuan-Pu
authors.initials: CP
authors.lastname: Liu
authors.forename: Yi-Feng
authors.initials: YF
authors.lastname: Lai
authors.forename: Cheng-Yu
authors.initials: CY
authors.lastname: Wang
authors.forename: Hung-Chin
authors.initials: HC
authors.lastname: Chung