Ultrafast terahertz modulation characteristic of tungsten doped vanadium dioxide nanogranular film revealed by time-resolved terahertz spectroscopy

作者：Xiao, Yang; Zhai, Zhao-Hui; Shi, Qi-Wu; Zhu, Li-Guo^*; Li, Jun; Huang, Wan-Xia; Yue, Fang; Hu, Yan-Yan; Peng, Qi-Xian; Li, Ze-Ren

来源：Applied Physics Letters, 2015, 107(3): 031906.

DOI：10.1063/1.4927383

• INSULATOR-TRANSITION
• METAL TRANSITION
• CARRIER DYNAMICS
• CONDUCTIVITY
• NANOWIRES

The ultrafast terahertz (THz) modulation characteristic during photo-induced insulator-to-metal transition (IMT) of undoped and tungsten (W)-doped VO2 film was investigated at picoseconds time scale using time-resolved THz spectroscopy. W-doping slows down the photo-induced IMT dynamic processes (both the fast non-thermal process and the slow metallic phase propagation process) in VO2 film and also reduces the pump fluence threshold of photo-induced IMT in VO2 film. Along with the observed broadening of phase transition temperature window of IMT in W-doped VO2, we conclude that W-doping prevents metallic phase domains from percolation. By further extracting carrier properties from photo-induced THz conductivity at several phase transition times, we found that the electron-electron correlation during IMT is enhanced in W-doped VO2.

• 出版日期2015-7-20
• 单位中国工程物理研究院; 中国工程物理研究院流体物理研究所