AACVD of CuN on AlO Using CuCl and NH.

CuN has been grown on m-AlO by aerosol-assisted chemical vapor deposition using 0.1 M CuCl in CHCHOH under an excess of NH at 600 °C, which led to the deposition of Cu that was subsequently converted into CuN under NH: O at 400 °C in a two-step process without exposure to the ambient. The reaction of CuCl with an excess of NH did not lead to the growth of CuN, which is different to the case of halide vapor phase epitaxy of III-V semiconductors.

Core-shell PbS/Sn:InO and branched PbInS/Sn:InO nanowires in quantum dot sensitized solar cells.

Core-shell PbS/Sn:InO and branched PbInS/Sn:InO nanowires have been obtained via the deposition of Pb over Sn:InO nanowires and post growth processing under HS between 100 °C-200 °C and 300 °C-500 °C respectively. The PbS/Sn:InO nanowires have diameters of 50-250 nm and consist of cubic PbS and InO while the PbInS/Sn:InO nanowires consist of PbInS branches with diameters of 10-30 nm and an orthorhombic crystal structure. We discuss the growth mechanisms and also show that the density of electrons in the n-type Sn:InO core is strongly dependent on the thickness of the p-type PbS shell, which must be smaller than 30 nm to prevent core depletion, via the self-consistent solution of the Poisson-Schrödinger equations in the effective mass approximation.

Ultrafast Spectroscopy and Red Emission from β-Ga2O 3/β-Ga 2S 3 Nanowires.

Ultrafast pump-probe and transient photoluminescence spectroscopy were used to investigate carrier dynamics in β-Ga2O3 nanowires converted to β-Ga2O3/Ga2S3 under H2S between 400 to 600 °C. The β-Ga2O3 nanowires exhibited broad blue emission with a lifetime of 2.4 ns which was strongly suppressed after processing at 500-600 °C giving rise to red emission centered at 680 nm with a lifetime of 19 μs.

Electronic properties of core-shell nanowire resonant tunneling diodes.

The electronic sub-band structure of InAs/InP/InAs/InP/InAs core-shell nanowire resonant tunneling diodes has been investigated in the effective mass approximation by varying the core radius and the thickness of the InP barriers and InAs shells. A top-hat, double-barrier potential profile and optimal energy configuration are obtained for core radii and surface shells >10 nm, InAs middle shells <10 nm, and 5 nm InP barriers. In this case, two sub-bands exist above the Fermi level in the InAs middle shell which belongs to the m = 0 and m = 1 ladder of states that have similar wave functions and energies.

Zn3N2 nanowires: growth, properties and oxidation.

Zinc nitride (Zn3N2) nanowires (NWs) with diameters of 50 to 100 nm and a cubic crystal structure have been grown on 1 nm Au/Al2O3 via the reaction of Zn with NH3 including H2 between 500°C and 600°C. These exhibited an optical band gap of ≈ 3.2 eV, estimated from steady state absorption-transmission spectroscopy.

The nitridation of ZnO nanowires.

ZnO nanowires (NWs) with diameters of 50 to 250 nm and lengths of several micrometres have been grown by reactive vapour transport via the reaction of Zn with oxygen on 1 nm Au/Si(001) at 550°C under an inert flow of Ar. These exhibited clear peaks in the X-ray diffraction corresponding to the hexagonal wurtzite crystal structure of ZnO and a photoluminescence spectrum with a peak at 3.3 eV corresponding to band edge emission close to 3.

Ultrafast hole carrier relaxation dynamics in p-type CuO nanowires.

Ultrafast hole carrier relaxation dynamics in CuO nanowires have been investigated using transient absorption spectroscopy. Following femtosecond pulse excitation in a non-collinear pump-probe configuration, a combination of non-degenerate transmission and reflection measurements reveal initial ultrafast state filling dynamics independent of the probing photon energy. This behavior is attributed to the occupation of states by photo-generated carriers in the intrinsic hole region of the p-type CuO nanowires located near the top of the valence band.

An investigation into the conversion of In2O3 into InN nanowires.

Straight In2O3 nanowires (NWs) with diameters of 50 nm and lengths ≥2 μm have been grown on Si(001) via the wet oxidation of In at 850°C using Au as a catalyst. These exhibited clear peaks in the X-ray diffraction corresponding to the body centred cubic crystal structure of In2O3 while the photoluminescence (PL) spectrum at 300 K consisted of two broad peaks, centred around 400 and 550 nm. The post-growth nitridation of In2O3 NWs was systematically investigated by varying the nitridation temperature between 500 and 900°C, flow of NH3 and nitridation times between 1 and 6 h.

Gallium hydride vapor phase epitaxy of GaN nanowires.

Straight GaN nanowires (NWs) with diameters of 50 nm, lengths up to 10 μm and a hexagonal wurtzite crystal structure have been grown at 900°C on 0.5 nm Au/Si(001) via the reaction of Ga with NH3 and N2:H2, where the H2 content was varied between 10 and 100%. The growth of high-quality GaN NWs depends critically on the thickness of Au and Ga vapor pressure while no deposition occurs on plain Si(001).

Tin Oxide Nanowires: The Influence of Trap States on Ultrafast Carrier Relaxation.

We have studied the optical properties and carrier dynamics in SnO(2) nanowires (NWs) with an average radius of 50 nm that were grown via the vapor-liquid solid method. Transient differential absorption measurements have been employed to investigate the ultrafast relaxation dynamics of photogenerated carriers in the SnO(2) NWs. Steady state transmission measurements revealed that the band gap of these NWs is 3.

Synthesis of Tin Nitride Sn(x)N(y) Nanowires by Chemical Vapour Deposition.

Tin nitride (Sn(x)N(y)) nanowires have been grown for the first time by chemical vapour deposition on n-type Si(111) and in particular by nitridation of Sn containing NH(4)Cl at 450 degrees C under a steady flow of NH(3). The Sn(x)N(y) nanowires have an average diameter of 200 nm and lengths >/=5 mum and were grown on Si(111) coated with a few nm's of Au. Nitridation of Sn alone, under a flow of NH(3) is not effective and leads to the deposition of Sn droplets on the Au/Si(111) surface which impedes one-dimensional growth over a wide temperature range i.

Low Temperature Growth of In2O3and InN Nanocrystals on Si(111) via Chemical Vapour Deposition Based on the Sublimation of NH4Cl in In.

Indium oxide (In2O3) nanocrystals (NCs) have been obtained via atmospheric pressure, chemical vapour deposition (APCVD) on Si(111) via the direct oxidation of In with Ar:10% O2at 1000 °C but also at temperatures as low as 500 °C by the sublimation of ammonium chloride (NH4Cl) which is incorporated into the In under a gas flow of nitrogen (N2). Similarly InN NCs have also been obtained using sublimation of NH4Cl in a gas flow of NH3. During oxidation of In under a flow of O2the transfer of In into the gas stream is inhibited by the formation of In2O3around the In powder which breaks up only at high temperatures, i.

Femtosecond Carrier Dynamics in In(2)O(3) Nanocrystals.

We have studied carrier dynamics in In(2)O(3) nanocrystals grown on a quartz substrate using chemical vapor deposition. Transient differential absorption measurements have been employed to investigate the relaxation dynamics of photo-generated carriers in In(2)O(3) nanocrystals. Intensity measurements reveal that Auger recombination plays a crucial role in the carrier dynamics for the carrier densities investigated in this study.