Investigation on IV characteristics of current induced metal insulator transition in VO2 device

Abstract

The I-V characteristics of two terminal planar VO2 film devices are investigated as the devices undergo the current induced metal insulator transition ( I-MIT). The I-MIT occured when the device resistivity reached similar to 7 Omega cm, where metallic grains formed initial conductive current path within insulating matrix. The transition time needed for the I-MIT increased with increasing external resistance, R-EXT, connected to the device in series, i.e. similar to 390 mu s (R-EXT = 5 k Omega) to similar to 1400 ms (R-EXT = 20 k Omega). The transition time is closely related to the RC time delay from capacitance discharge of the VO2 device. During the I-MIT, the amount of discharge current was estimated as large as similar to 100 mA, which was larger than the current just before the I-MIT. After the I-MIT, the current density decreased from 1.1 x 10(6) A/cm(2) to 6.5 x 10(5) A/cm(2), suggesting a large temperature changes up to similar to 300 degrees C. (C) 2017 Elsevier B.V. All rights reserved.