Effect of free-carrier concentration on the phase transition and vibrational properties of VO2

Abstract

The effects of native defect doping concentration on the phase transition properties of vanadium dioxide thin films are investigated. The onset temperature of the metal-insulator transition is found to depend on the free-carrier concentration and to correlate with an abrupt change in the temperature dependence of the vibrational energies of the V-O related Raman band. A phase diagram is proposed identifying insulating, intermediate, and conducting regimes. The intermediate region is attributed to a mixed phase.