Direct measurement of compositional complexity-induced electronic inhomogeneity in VO2 thin films grown on gate dielectrics
Abstract
We report on measurements of variation in metal-insulator transition characteristics through thickness in VO2 film grown on model SiO2 gate insulator by nanometric scale controlled etching followed by electrical and compositional measurements. The phase transition magnitude defined as ratio of resistivity at 25 °C to that at 100 °C of VO2 decreases from ∼159 at the surface to ∼14 at ∼10 nm away from a VO2/SiO2 interface, showing a difference of >10 times, while that for a VO2 thin film grown with identical conditions on single crystal sapphire only shows ∼3 times difference. The off-stoichiometric composition near the VO2/SiO2 interface induced by unoriented growth on amorphous SiO2 is likely responsible for the dramatic change in transition characteristics.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- May 09, 2011
- Source ID
- 10.1063/1.3590920
Entities
People
- Shriram Ramanathan
- Yang Zheng
Organizations
- Harvard University
- Office of Naval Research