Dynamic Control of Photoresponse in VO₂ Through Phase Manipulation

Vanadium dioxide (VO 2 ), a representative phase‐transition material, exhibits nonlinear optical responses during its transition from an insulating to a metallic state. By investigating the transient photoresponses of a VO 2 thin film at different temperatures, additional slow‐growth and hybrid phases are discovered between the insulating phase at low‐temperature and metallic phase at high‐temperature. The amplitude of the VO 2 photoresponse at 68 °C in the slow‐growth phase is observed to be 5.5 times greater than that at room temperature. The controllability of relaxation time is also demonstrated from a few tens of picoseconds to a few nanoseconds. The optimized conditions for all‐optical modulation applications are explored.