Bidirectional Current Triggering in VO₂-Based Device with High-Repetition-Rate Pulse Beams Using Near-Infrared Laser...

Here we report bidirectional current triggering (BCT) with a high repetition rate, achieved in a twoterminal planar device based on a vanadium dioxide (VO₂) thin film by using a laser diode with a center wavelength of 976 nm as an excitation source. The VO₂ thin film was grown on a sapphire (Al₂O₃) substrate using a pulsed laser deposition method, and the two-terminal planar device was fabricated by sawing the grown film into microscale unit devices, each of which was then attached onto a printed circuit board. Current triggering was performed by controlling the output power of the laser beam incident on the device surface. The proposed device allows stable current triggering operation even with laser pulses of higher repetition rate and lower energy because it is designed to have low heat capacity and thermal conductivity. Experimental results showed that a BCT of up to 30 mA was achieved at the maximum repetition rate of 8.0 Hz. The switching contrast between off- and on-state currents was calculated to be ~7295, and average rising and falling times of the current triggering were measured to be ~18.3 and ~22.5 ms, respectively.