Single crystalline InN nanorods by H-MOVPE
|Olga Kryliouk , Hyun Jong Park , Joshua Mangum , Tim Anderson|
University of Florida (UF), 227 Chemical Engineering Bldg., Gainesville, FL 32611, United States
Nanomaterials are experiencing a rapid development in recent years due to their exciting potential applications in different areas. InN has been investigated intensively as a constituent of GaxIn1-xN and AlxIn1-xN which has been used as active layer in optoelectronic and electronic devices for over a decade. Although InN itself is still less studied material compare to GaN and AlN, the interest in the InN has been increased remarkably. The optical characterization of improved wurtzite InN crystals, although still a subject of debate, has a reported band gap in the range 0.65 to 0.9 eV. This band gap energy is considerably lower than the previously accepted value (Eg = 1.9 eV), and thus some additional applications of InN, such as solar cell and infrared laser diode, are possible. The addition of Ga (Eg = 3.4 eV) makes it possible to create a band gap range of 0.7 to 3.4 eV, which covers virtually the entire solar spectrum.
InN nanorods were grown by H-MOVPE technique. This technique is promising for the development of high efficiency III-Nitrides-based nanosize optoelectronic and electronic devices. Growth of InN using MOVPE has several challenges. The growth temperature is limited to the range of 450~650C because of the high vapor pressure of nitrogen over InN and low dissociation rate of NH3. A high V/III ratio (>104) is usually required to prevent In droplet formation at growth temperature. The basic growth parameters, such as growth temperature, V/III and HCl/TMI ratios, and the growth mechanisms were investigated. A novel method was proposed to prevent In droplets formation. Equilibrium thermodynamic calculations of the In-Ga-N-Cl-H system, reaction pathways studies are complemented by experimental work. A wide range of characterization techniques, such as: XRD, AFM, SEM/EDS, TEM, AES, XPS, and PL were employed in this study.
Presentation: invited oral at E-MRS Fall Meeting 2005, Symposium A, by Olga Kryliouk
See On-line Journal of E-MRS Fall Meeting 2005
Submitted: 2005-05-27 19:27 Revised: 2009-06-07 00:44