Depressed phase transition in solution-grown VO2 nanostructures.
The first-order metal-insulator phase transition in VO(2) is characterized by an ultrafast several-orders-of-magnitude change in electrical conductivity and optical transmittance, which makes this material an attractive candidate for the fabrication of optical limiting elements, thermochromic coatings, and Mott field-effect transistors. Here, we demonstrate that the phase-transition temperature and hysteresis can be tuned by scaling VO(2) to nanoscale dimensions. A simple hydrothermal protocol yields anisotropic free-standing single-crystalline VO(2) nanostructures with a phase-transition temperature depressed to as low as 32 degrees C from 67 degrees C in the bulk. The observations here point to the importance of carefully controlling the stoichiometry and dimensions of VO(2) nanostructures to tune the phase transition in this system.
Whittaker
Luisa
L
Department of Chemistry, University at Buffalo, State University of New York, Buffalo, New York 14260, USA.
Jaye
Cherno
C
Fu
Zugen
Z
Fischer
Daniel A
DA
Banerjee
Sarbajit
S