In order to study the optical behaviors of a single ZnO
nanowire, the products were ultrasonically dispersed into alcohol
and deposited onto a transparent quartz slide. The UV light of
325 nm from a He–Cd laser was focused on a single ZnO nanowire.
Significantly, the local light emission of the single ZnO nanowire
under laser excitation can be imaged easily with a CCD camera.
Fig. 3 shows an optical microscope image of a single nanowire,
which displays pronounced emission from the end facet. The emission
from the nanowire body was too weak to be observed. The
optical image shows a spatial map of the emission intensities with
a maximum at the end of the nanowire clearly. The results indicate
that the emitted light was effectively transported to the end of the
nanowire. In order to investigate the nature of the end emission by
the spatially resolving spectra, which were carried out by the PL
measurements