Outdiffusion of the excess carbon in SiC films into Si substrate during film growth

Journal of Experimental Nanoscience

2011

GaN nanowires are fabricated on Si substrates by ammoniating Ga 2 O 3 /NiCl 2 thin films using chemical vapour deposition method. The influence of reaction temperature on microstructure, morphology and optical properties of GaN nanowires is characterised by X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectrophotometer, scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy and photoluminescence. The results demonstrate that the GaN nanowires are single crystalline and exhibit hexagonal wurtzite symmetry. The best crystalline quality was achieved for an reaction temperature of 1150 C for 15 min. The growth process follows vapour-liquid-solid mechanism and Ni plays an important role as the nucleation point and as a catalyst.

Section: Microstructure and Components Analysissupporting

confidence: 83%

Synthesis of GaN nanowires by CVD method: effect of reaction temperature

Shi

Wang

Journal of Experimental Nanoscience

2011

“…[14] There is no Ga-O bond and other absorption band in the spectrum; [15] therefore, Ga 2 O 3 films react with NH 3 completely at 1223 K (950°C) for 15 minutes and form hexagonal type GaN crystal, which is the same as the results of the XRD. The Ga-N bond intensity of the sample whose ammoniating time is 20 minutes is stronger than those of the other two samples, which proves the sample has the highest crystalline quality and is also the same as the results of the XRD.…”

Section: Resultsmentioning

confidence: 52%

GaN Nanorods Catalyzed with Mo: Effect of Ammoniating Time on Microstructure, Morphology, and Optical Properties

Shi

2010

Metall Mater Trans A

GaN nanorods have been successfully grown on Si (111) substrates by magnetron sputtering through ammoniating Ga 2 O 3 thin films catalyzed with Mo. The influence of the ammoniating time on the growth of GaN nanorods was analyzed, in particular, by X-ray diffraction (XRD), X-ray photoelectron spectroscopy, Fourier transform infrared (FT-IR) spectrometer, scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), and photoluminescence (PL) spectrum. The results demonstrate that the GaN nanorods are single crystal with hexagonal wurtzite structure, which have high crystalline quality. The GaN nanorods after ammoniation at 1223 K (950°C) for 20 minutes have good emission properties and the highest crystalline quality with 100-to 200-nm diameter and several-micron length. The growth direction of these nanorods is along the orientation of (100) crystal plane. A small red shift occurs because of the band-gap change caused by the tensile stress of the one-dimensional GaN nanorods along the axial direction.

“…The band at 1,040-1,120 cm -1 correlates to the Si-O-Si asymmetric stretching vibration caused by the oxygenation of the Si substrate. That is, the bands centered at 617 and 1,040-1,120 cm -1 present close relation with the Si substrates [16,17]. The band located at 809 cm -1 maybe correlate to Ni 2?…”

Section: Resultsmentioning

confidence: 59%

Synthesis of β-Ga2O3 nanorods by catalyzed chemical vapor deposition and their characterization

Wei

Zang

J Mater Sci: Mater Electron

et al. 2014

b-Ga 2 O 3 nanorods have been synthesized by chemical vapor deposition using CaF 2 as dispersant and Ni 2? ions as catalyst. The composition, crystal structure, morphology, and optical property were characterized. X-ray diffraction data indicate the product to be high purity b-Ga 2 O 3 . The nanorods are 40-100 nm in diameter and about several microns in length and present a core-shell structure. A broad and strong emission band ranging from 300 to 650 nm exists with four Gaussian bands centered at 357 (UV), 420 (blue), 475 (dark blue), and 529 nm (green). Growth of b-Ga 2 O 3 nanorods agrees with the vapor-solid growth mechanism.