蓝宝石衬底上VO_2薄膜的PLD外延生长

Epitaxial Growth and Characterization of VO_2 Thin Film on Sapphire by Pulsed Laser Deposition

采用脉冲激光沉积技术,在c面蓝宝石衬底上制备出了VO_2薄膜。利用X射线衍射、Raman光谱、原子力显微镜对生长的样品的结构和表面形貌进行了表征;利用霍尔效应测试仪和紫外-可见-红外光分光光度计分别测试薄膜的方块电阻和透过率。结果表明:在蓝宝石衬底上生长出了结晶性能良好的VO_2薄膜;相变前后其方块电阻变化高达4个数量级,红外透过率的变化高达56%。VO_2薄膜表现出了良好的金属-绝缘转变特性。

The epitaxial VO_2 thin films were synthesized by pulsed laser deposition on substrate of c-oriented sapphire. The impact of the growth conditions,including but not limited to oxygen partial pressure,energy density of laser and substrate temperature,on the microstructures and properties of the VO_2 coatings was investigated with Xray diffraction,Raman spectroscopy,atomic force microscopy,Hall-effect measurement and ultra violet visible infrared spectroscopy. The results show that high quality,compact VO_2 coatings with small roughness were deposited under the optimized growth conditions. The phase transition resulted in a four-order of magnitude change in the sheet resistance and a 56% variation in the transmittance of infrared light. In addition,the VO_2 coatings exhibit excellent metal-insulator transition（ MIT） properties.