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 ∼7 Ωcm, where metallic grains formed initial conductive current path within insulating matrix. The transition time needed for the I-MIT increased with increasing external resistance, REXT, connected to the device in series, i.e. ∼390 μs (REXT = 5 kΩ) to ∼1400 μs (REXT = 20 kΩ). 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 ∼100 mA, which was larger than the current just before the I-MIT. After the I-MIT, the current density decreased from 1.1 × 106 A/cm2 to 6.5 × 105 A/cm2, suggesting a large temperature changes up to ∼300 °C.
Bibliographical noteFunding Information:
H. L. Ju and B. S. Mun would like to thank the Basic Science Research Program for support through the National Research Foundation of Korea (NRF) funded by the Korean government (MOE) ( NRF-2015R1D1A1A01059297 and NRF-2015R1A2A2A01004084 ). B.S. Mun would like to acknowledge the supports from the SRC program through the NRF funded by the MOE ( NRF-2015R1A5A1009962 ), Korea Basic Science Institute Research Grant ( E35800 ), and “ GRI (GIST Research Institute) Project ” through a grant provided by GIST in 2017.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Physics and Astronomy(all)