Single Crystalline InN Nanorods: Controlled Synthesis, Characterizations, and Applications
O. Kryliouk, H.J. Park, J. Mangum, T. Anderson, A. Davydov, I. Levin and Z. Liliental-Weber
University of Florida, US
III-Nitrides, nanorods, H-MOVPE
InN has been intensively studied recently due to its controversial lower band-gap energy and high carrier mobility. Controlled synthesis of 1D III-Nitrides creates an opportunity for their fundamental study and new applications for future electronic and photonic devices. Single-crystalline InN nanorods (NRs) were successfully grown on c-, a-, r- Al2O3, GaN, and Si substrates by non catalytic, template-free hydride metal-organic vapor phase epitaxy (H-MOVPE). Complex chemical equilibrium calculations were performed for the In-Cl-H-N system considering possible reactions to determine optimum conditions for InN nanorod formation. It was evaluated thermodynamically and confirmed experimentally that the domain of NRs growth lies in the vicinity of the growth–etch transition. Dislocation-free, high-quality InN NRs with [00.1] growth axis were formed via an apparent solid-vapor growth mechanism. The nanorods diameter, density, and orientation were controlled by growth temperature, substrate selection, and HCl/TMIn and N/In inlet molar ratios. Extensive studies of the nanorods were performed by FESEM, GIXD, TEM, EDS, Raman Scattering, and PL. Ongoing efforts in our research on InN NRs foundational applications will be presented. InN NRs offer an effective way for the nanoheteroepitaxial approach to grow crack-free thick GaN films on Si substrates. Thick (~ 40 m), crack-free GaN was successfully grown on Si substrates using InN NRs interlayer. Pt-coated InN NRs appear well-suited to detection of ppm concentration levels of hydrogen at room temperature. The InN NRs can be placed on cheap transparent substrates such as glass, making them attractive for low-cost sensing applications. Furthermore, it was demonstrated that they can operate at very low power conditions.
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Nanotech 2007 Conference Program Abstract