semiconductor nanowires and nanotubes

... quantum confinement ■ Abstract Semiconductor nanowires and nanotubes exhibit novel electronic and optical properties owing to their unique structural one-dimensionality and possible quantum confinement ... in our laboratories for the ZnO and GaN nanowire systems with epitaxial arrays (32), combs (54), and single nanowires (45, 101). ZnO and GaN are wide bandgap semiconductor...

Ngày tải lên: 20/03/2014, 13:07

... fabricated as well. The analytic results of the morphology and microstructure confirmed the orientation and the amorphous nature of the SiNWs, and the high dispersion of Au nanoparticles on the surface ... semi- conducting, mechanical, and optical properties, as well as their potential applications in mesoscopic research and nanodevices. They are, for example, considered as candidate...

Ngày tải lên: 16/03/2014, 15:06

... single barriers in nanowires From knowledge of the band structure and band alignment in bulk III–V materials one could predict that the conduction band oset between InAs and InP should be at ... for nanowires. This and most other methods are however not able to form heterostructures inside the nanowires. 2. Vapor–liquid–solid growth mode of nanowires Already during the 1960s Wa...

Ngày tải lên: 16/03/2014, 15:20

... earlier works, for example, by Dittmar and Neumann [25], Ruth and Hirth [26] and Blakely and Jackson [27]. While in a given growth experiment the wire lengths and diameters are anyway dictated by ... f(R) but at different temperatures T and fluxes V. Some data and on the L(T) and L(V) dependencies of MBE grown Ga(Al)As nanowires have been recently ob- tained and modeled in R...

Ngày tải lên: 16/03/2014, 15:32

... stability and optical transparency of the composite films. The IR spectrum of the hydrated titanium dioxide [h-TiO 2 ] shows a large broad band between 3250 and 3490 cm −1 and narrow bands at 1641 and ... Results and discussion 3.1. SEM observations of TiO 2 nanowires SEM pictures revealed that TiO 2 nanowires were successfully fabricated by a hydrothermal method in our laborator...

Ngày tải lên: 19/03/2014, 16:47

... car- bothermal reduction [22,23], and template method [24], etc. have been developed to fabricate SnO 2 nanowires. However, the as- synthesized nanowires easily bend and length and diameter is not uniform, ... 1c) clearly indicates that these nanowires are of uniform size and smooth surface, and the average diameter and length of these nanowires are 80 nm and 5 ␮m, respec...

Ngày tải lên: 19/03/2014, 16:48

... have very poor solar-blind performance and wide bandgap systems offer improved speed and lower dark currents. Currently the most commonly used wide bandgap semiconductor system for UV detection ... metabolites and markers, and this can be valuable in measuring both medication adherence and in determining the blood levels of these drugs and medications. Some of today’s blood and...

Ngày tải lên: 20/03/2014, 13:06

... images, both diameter and length of nanowires were larger than those of nanotubes; the diameter and length of nanowires were about 10–50 nm and several mm, respectively. TEM images and nitrogen adsorption isotherms ... 800 and 900 1C, respectively. The SEM images of (a) and (b) show almost only nanowires. Those of (c) and (d) show both nanowires and small amount of par...

Ngày tải lên: 20/03/2014, 13:08

... 200kV, Philips CM-200 at 200kV and Philips TECNAI-10 at 100 kV) and energy-dispersive X-ray spectroscopy (EDX). 3. Results and discussion 3.1. Nanotubes Titanium oxide nanotubes can be formed in ... obtained from with: (a) anatase and NaOH (10mol/L) at 150 ◦ C; (b) amorphous TiO 2 and NaOH (10 mol/L) at 180 ◦ C; (c) anatase and NaOH (10 mol/L) at 220 ◦ C; and (d) anatase an...

Ngày tải lên: 20/03/2014, 13:11

... conduction band in a typical semiconductor. In semiconductors only electrons in the conduction band and holes in the valence band can carry current. 88 Chapter 2. Semiconductor Bandstructure E c E V D ENSITY ... electrons populate both the L and X valleys in addition to the Γ-valley, making these regions of bandstructure quite important. The valence band of GaAs has the standard HH, LH...

Ngày tải lên: 24/01/2014, 17:34