Phase transition properties of vanadium oxide thin films irradiated by nanosecond laser

Vanadium oxide (VO2) thin films were successfully deposited using pulsed laser deposition (PLD) method. The samples were identified as polycrystalline thin films by analysis of X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) . Phase transition properties of VO2 films irradiated by nanosecond laser were investigated by pump-probe technique. The results show that the minimum response time is 12 ns at repetition rate of 160 Hz. Moreover, the recovery time of phase transition varies with laser energy according to natural exponential law. Our simulation results suggest that the recovery time of phase transition correlates with thermal conductivity and thermal diffusion coefficient of substrates for the same laser energy.