substrates: Ni nanowire arrays (a) and carbon nanotube arrays (b).
shift and enhancement – results of quantum confinement effects.
dielectric contrast between nanowire and surrounding environment.
recombining – enhance the efficiency of solar cells.
• Nanowires with optical properties tuned by changing aspect ratio.
resonance cavities; the lasing properties.
important role to photo-sensitivity and PL of oxide 1-D nanostructures.
nanostructures: Holmes JD, Science, 2000.
of several micrometers by a supercritical solution-phase approach.
TEM images of 4 CdSe nanorod samples.
The scale bar is 50 nm.
(from left to right), excited at 450 nm.
angles. The data are fit in 1/length (1/L), 1/width (1/W), and aspect ratio (L/W).
1.8563 -2.0835/L2 + 4.5507/W2 - 0.0018(L/W)2 + 0.0001(L/W)3 + 10.5824/L3 0.3833/W3.
10 periods of Zn0.8Mg0.2O/ZnO on ZnO nanorods.
A: 1.1 nm wells and B: 2.5 nm wells.
nanodots and nanowires did not exactly follow the particle-in-a-box prediction.
ħ is Planck's constant, e is the electron charge.
between electron and hole in perturbation theory.
This mode provides excellent fits to experimental results.
ZnO and GaN nanowires with epitaxial arrays and single nanowires.
excitation conditions. GaN has an electron-hole plasma lasing mechanism.
to the large diffraction losses.
of 1 to 3 half-passes before escaping from the cavity.
(lasing) at high pump power.
independent of pump power but shows significant red-shift near saturation.
GaN nanowires show a consistent red-shift from threshold to saturation.
far-field image of belt lasing emission.
component (∼70 ps) owing to free-exciton spontaneous emission.
is about 70 ps and short component is about 9 ps (red) and 4 ps (black).
in circuits and activated by electron-injection rather than optical pumping.
a, A nanowire as an optical waveguide, with cleaved ends of a Fabry–Perot cavity.
b, SEM image of a cleaved CdS nanowire end.
mm away from the nanowire end. The white arrow highlight the nanowire end.
higher pump power (80 mW) exhibiting periodic intensity variation.
200 mW (red, blue and green) recorded at 8 K.
emission from nanowire end (green) shows superlinear behavior above 125 mW.
narrows to the instrument-resolution value at high power.
observed when lasing in planar devices pumped close to threshold.
are very similar to the low-temperature optically pumped results.
difficult to integrate directly with Si microelectronics.
capable of emitting a wide range of colors, used in flat displays.
great commercial interest in FEDs and other electronic devices.
Besides CNTs, some other inorganic semiconductor nanostructures used for fieldemitters, such as ZnO, Si, WO3, SiC, ZnS, AlN.
anode through a barrier (vacuum) in the presence of a high electric field.
(nanowires or nanotubes) produce higher field-emission currents.
and sharp tips or edges can greatly increase an emission current.
ultra-sharp (~ 1 nm diameter) and ultra-high density (109 – 3 × 1011 cm-2) SiCcapped Si nanotip arrays.
at a 3 mA cm-2 current density).
relationship for an ideal field emitter.
pixels is 2.5 mm. The dark spots on the anode correspond to the pixels (b).
with an arrow mark is indexed as '1A'.
Models of 3-D nanostructures made from DNA.