Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542, Singapore.
J Phys Condens Matter. 2012 Oct 17;24(41):415604. doi: 10.1088/0953-8984/24/41/415604.
We studied the ultrafast dynamic behavior of the photoinduced insulator–metal phase transition in VO2 thin film using optical pump–terahertz probe spectroscopy with different excitation fluences and at different temperatures. We observed two processes in the insulator–metal phase transition in VO2: a fast process and a slow process. The fast process is a nonthermal process, which is ascribed to the nucleation of the metal phase, while the slow process is strongly affected by temperature and is ascribed to the thermally driven growth and coalescence of metal domains in VO2. The transient complex conductivity spectra at different delay times are also investigated.
我们使用不同激发通量和不同温度的光泵浦太赫兹探针光谱研究了 VO2 薄膜中光诱导绝缘-金属相转变的超快动力学行为。我们在 VO2 的绝缘-金属相转变中观察到两个过程：一个快过程和一个慢过程。快过程是非热过程，归因于金属相的成核，而慢过程强烈受温度影响，归因于 VO2 中金属畴的热驱动生长和合并。我们还研究了不同延迟时间的瞬态复电导率谱。
