Study of the phase evolution, metal-insulator transition, and optical properties of vanadium oxide thin films
Study of the phase evolution, metal-insulator transition, and optical properties of vanadium oxide thin films
复制标题
氧化钒薄膜的相演化、金属-绝缘体转变和光学性能研究
DOI：
10.1364/ome.6.003609
复制
发表时间：
2016-11-01
影响因子：
2.8
通讯作者：
Bi, Lei
中科院分区：
文献类型：
--
作者：
Huang, Taixing;Yang, Lin;Bi, Lei
VO2 thin films featuring a metal-insulator transition (MIT) at 68 degrees C with a large reversible tunability of the optical property have attracted great interest recently. Due to the complex phase and valence states of the vanadium oxides, understanding the microstructure and optical properties of this material with different oxygen stoichiometries has been challenging. In this study, we show that confocal Raman microscopy mapping can resolve the phase distribution in a large vanadium oxide thin film sample area, therefore providing a useful tool for a structure-property relationship study of this material. A new Raman peak at 166 cm(-1) is observed in oxygen rich VO2 films, which forms micron size islands in the films, and is attributed to the characteristic peak of V4+/V5+ mixed valence states. The mixed valence state structure exists in a large oxygen partial pressure window during thin film fabrication. By joining the structural analysis and optical constants fitted by the Drude-Lorentz model using effective medium theory, the influence of different phases and valence states to the optical constants of the vanadium oxide thin films is clearly observed. These results provide in-depth understanding of the structure-optical property relationship of vanadium oxide thin films. (C) 2016 Optical Society of America
