Mesoscopic Effects and Metal-Insulator Transition in Vanadium Oxide Nanowires
Abstract
Investigations were performed with a view to making such devices in the surface, or in thin crystals, of vanadium dioxide. This required developing suitable crystals, testing techniques to shape, pattern and dope them, improving understanding of the electrical and optical properties of the phases and the metal-insulator transition (MIT) between them, and establishing control of the MIT. We found several improved ways to grow, manipulate, clean, pattern and dope VO2 nanobeams, rods and plates, and epitaxial VO2 films on TiO2. We studied the competition between the two insulating phases, M1 and M2, and the metallic phase using near-field scanning optical techniques and Raman spectroscopy. Also, using scanning photocurrent microscopy we investigated for the first time the photoresponse of this correlated material. We determined that the response is purely photothermal, meaning that carrier relaxation to thermal equilibrium in the insulating phase is much more efficient than in band semiconductors, consistent with strong correlations.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 08, 2012
- Accession Number
- ADA579160
Entities
People
- David H. Cobden
Organizations
- University of Washington