Growth and characterization of gallium nitride nanowires produced on different sol-gel derived catalyst dispersed in tit
- PDF / 795,673 Bytes
- 7 Pages / 612 x 792 pts (letter) Page_size
- 95 Downloads / 171 Views
S. Chattopadhyaya) Institute of Atomic & Molecular Sciences, Academia Sinica, Taipei-106, Taiwan
C.W. Hsu Department of Chemistry, National Taiwan Normal University, Taipei-116, Taiwan
C.H. Shen Institute of Atomic & Molecular Sciences, Academia Sinica, Taipei-106, Taiwan
L.C. Chen Center for Condensed Matter Sciences, National Taiwan University, Taipei-106, Taiwan
C.C. Chen Department of Chemistry, National Taiwan Normal University, Taipei-116, Taiwan
K.H. Chen Institute of Atomic & Molecular Sciences, Academia Sinica, Taipei-106, Taiwan
H.Y. Lee Research Division, Synchrotron Radiation Research Center, Hsinchu, Taiwan (Received 4 October 2003; accepted 8 March 2004)
Sol-gel derived catalyst systems of cobalt, nickel, and iron were used in the growth of gallium nitride (GaN) nanowires by thermal chemical vapor deposition. A diffusion barrier matrix of titania (TiO2) has been used in which the catalysts were dispersed to have control of the catalyst particle sizes and hence on the size and morphology of the GaN nanowires. This single-step and cost-effective processing of the catalyst bed produced good-quality GaN naowires with comparable structural and optical properties with those previously reported. In a particular case, a stress-induced cubic admixture to the otherwise hexagonal structural symmetry was observed. The samples were characterized by high-resolution scanning electron microscopy, x-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, and cathodoluminescence studies.
I. INTRODUCTION
There has been substantial development in the field of gallium nitride (GaN) research during the past three decades, and the community is well aware of most of the potential optoelectronic and microwave applications of the wurtzite (hexagonal) and zinc blend (cubic) phases. Some fundamental and technological hurdles still exist before the material becomes commonplace. The problem of synthesizing the material to the structure, quality, and size of our choice and whatever lack of understanding of
a)
Address all correspondence to this author. e-mail: [email protected] DOI: 10.1557/JMR.2004.0220 1768
J. Mater. Res., Vol. 19, No. 6, Jun 2004
the defects associated with the material continue to provide the impetus for the ongoing research. Several deposition techniques have been adopted to produce different forms1–13 of the GaN material that may have optoelectronic uses. The advent of the nanotubes underlined the utility of the one-dimensional (1D) nanostructures in understanding the effect of dimensionality on the various physical, optolectronic, and other general properties of matter. GaN also occupied its due place in the 1D world with its nanowires/nanorods form14–17 that also showed the lasing action.18 Catalyst-assisted growth of GaN nanowires involving the vapor–liquid–solid (VLS) mechanism12,15,17 has been abundant due to the relative ease in the control of the dimensions. The selection of the catalyst material, the process of dispersing them with © 2004 Materials Resear
Data Loading...
