Bidirectional current triggering in planar devices based on serially connected VO₂ thin films using 965 nm laser...

Area of Science:

• Materials Science
• Condensed Matter Physics
• Optoelectronics

Background:

• Vanadium dioxide (VO2) exhibits a thermally induced phase transition with significant changes in electrical resistivity.
• Controlling this phase transition with external stimuli like lasers is crucial for developing novel electronic devices.

Purpose of the Study:

• To demonstrate bidirectional current triggering in a two-terminal VO2 device using a 965 nm laser diode.
• To investigate the transient response characteristics of laser-triggered currents in VO2 thin films.

Main Methods:

• Fabrication of a two-terminal planar device with serially connected VO2 thin films via pulsed laser deposition.
• Utilizing focused laser pulses to induce photo-thermal phase transitions for current triggering.
• Analyzing transient current responses under varying laser pulse widths and repetition rates.

Main Results:

• Achieved bidirectional current triggering up to 30 mA in the VO2 device.
• Observed a high switching contrast of approximately 8333 between off- and on-states.
• Measured fast switching times: ~39 ms rising and ~29 ms falling for 50 ms laser pulses.

Conclusions:

• The study successfully demonstrates laser-induced bidirectional current triggering in VO2 thin films.
• The observed high switching contrast and fast response times highlight the potential of VO2 for optoelectronic switching applications.
• This method offers a promising approach for developing advanced, optically controlled electronic components.