氧化钒薄膜的制备及其在光激励下对太赫兹波的调制

Preparation of VO_x thin film and its modulation for terahertz wave under laser excitation

采用磁控溅射法在蓝宝石基底上制备金属钒薄膜,然后在O2中快速热处理获得具有相变特性的VOx薄膜。实验对比了不同的热处理温度和热处理时间对薄膜性能的影响,薄膜的结晶状况用X射线衍射(XRD)进行分析;利用THz时域频谱系统,观测薄膜在不同激励光功率下的相变特性及其对THz波的调制作用。结果表明,在570℃条件下快速热处理60s所制得的VOx薄膜性能最佳,薄膜对THz波透过性最好,光激励后对THz波的调制作用最大,调制幅度达到83.9%,且引发相变的功率阈值低。

Vanadium thin film was grown on sapphire substrate by magnetron sputtering. And then the film was annealed in oxygen by the rapid thermal processing to get VOx thin film which has the property of semiconductor to metal transition. The experiment is conducted under different annealing temperatures and different annealing time which can affect the characteristics of VOx thin film. The X-ray diffraction （XRD） is employed to analyze the crystalline structure of the thin film. The terahertz （THz） transmis- sion modulation of VOx thin film under laser excitation with different power is studied by THz time-do- main spectroscopy （TDS）. The results show that the VOx thin film prepared in the experiment has the property of transition between insulator phase and metal phase. The best annealing condition of this VOx thin film is 570℃ with 60 s treatment. The terahertz transmission modulation of VOx thin film under laser excitation is high. The amplitude of modulation is 83.9 %. The starting power and the power range of transition are low. The VOx thin film can be applied in the study of light switch and modulator.