Laser-triggered current gating based on photothermal effect in VO₂ thin-film device using CO₂ laser

By incorporating a CO₂ laser centered at ~ 10.6 μm, a laser-triggered current gating of up to 50 mA was demonstrated in a two-terminal planar device based on a vanadium dioxide (VO₂) thin film grown by a pulsed laser deposition method. The laser-triggered current on/off gating was realized by controlling the beam power of the CO₂ laser to excite the VO₂ device. The transient responses of the laser-triggered currents were investigated when periodical laser pulses from the CO₂ laser stimulated the VO₂ device at a variety of pulse widths and repetition rates. A switching contrast between off- and on-state currents was calculated as ~ 12,195, and average rising and falling times were measured as ~ 37 and ~ 23 ms, respectively.