60 mA Bidirectional Current Gating in Vanadium-Dioxide-Based Planar Device Using CO₂ Laser.

Area of Science:

• Materials Science
• Condensed Matter Physics
• Optoelectronics

Background:

• Vanadium dioxide (VO₂) exhibits a thermally induced semiconductor-to-metal phase transition.
• Controlling this phase transition with external stimuli is crucial for developing novel electronic and optoelectronic devices.
• Previous methods for VO₂-based current gating have limitations in achieved current and switching contrast.

Purpose of the Study:

• To demonstrate high-current bidirectional gating in a two-terminal VO₂ device.
• To investigate the effect of CO₂ laser parameters on the current gating performance.
• To achieve the highest reported current gating and switching contrast in VO₂ devices using laser irradiation.

Main Methods:

• Fabrication of a two-terminal planar device using a highly resistive vanadium dioxide (VO₂) thin film grown by pulsed laser deposition.
• Irradiation of the VO₂ device with a CO₂ laser (10.6 μm) to induce a photothermally driven phase transition.
• Systematic investigation of laser modulation parameters (pulse width, repetition rate) and their influence on transient current responses.

Main Results:

• Achieved 60 mA bidirectional current gating in the VO₂ device.
• Demonstrated stable current gating at repetition rates of 0.5–3.0 Hz with a minimum pulse energy of ~766 mJ.
• Obtained a switching contrast of ~11089 between off- and on-state currents at a bias of ~5.4 V.
• Reported the highest on-state current (60 mA) and switching contrast to date for CO₂ laser-gated VO₂ devices.

Conclusions:

• Photothermally induced phase transition in VO₂ thin films enables efficient bidirectional current gating.
• The demonstrated 60 mA current gating and high switching contrast represent a significant advancement for VO₂-based optoelectronic applications.
• This method offers a promising pathway for developing high-performance laser-controlled electronic switches.