Current-controlled optical modulation in thin VO2 wires
We measured the current-voltage and infrared optical transmission characteristics of thin film VO2 wires over the metal-insulator phase transition. The phase transition had electrical or thermal characteristics depending on the wire geometry and applied current.
Local Temperature Redistribution and Structural Transition During Joule‐Heating‐Driven Conductance Switching in VO2
Joule-heating induced conductance-switching is studied in VO2 , a Mott insulator. Complementary in situ techniques including optical characterization, blackbody microscopy, scanning transmission X-ray microscopy (STXM) and numerical simulations are used. Abrupt redistribution in local temperature is shown to occur upon conductance-switching along with a structural phase transition, at the same current.
Electrical switching in single crystal VO2
Abstract I–V characteristics of single crystal vanadium dioxide has been measured using a constant current source in the ambient temperature region 220–325°K. The temperature of the crystal surface has also been measured. It is observed that the switching voltage ( V th ) increases but the current at switching ( I th ) decreases with decreasing temperature, giving a temperature independent threshold power ( V th × I th ). At switching, the temperature of the crystal surface increases only by 3–6°K above ambient for different ambient temperatures. These results can be qualitatively explained by assuming that a filament (channel) is formed before switching. The switching occurs when the temperature of this filament of finite width approaches the semiconductor-metal transition temperature. The initial width of the channel at switching decreases with decreasing temperature and at a given ambient temperature the channel width increases with increasing current in the post breakdown region.