研究目的
Investigating the interplay between the structural and electronic phase transitions during the insulator-to-metal transition in VO2 thin films with different thicknesses.
研究成果
The structural modifications in the material across the transition affect the metallic cluster shape in the vicinity of the percolation threshold, leading to an altered absorption by the localized plasmon resonances. The study shows that noninvasive optical characterization based on ellipsometry combined with appropriate modeling is a powerful method to provide details on the microscopic changes occurring in the material.
研究不足
The study is limited to VO2 thin films with thicknesses ranging from 100 to 800 nm. The effects of strain and grain boundaries on the transition are complex and not fully understood.
1：Experimental Design and Method Selection:
Temperature-dependent spectroscopic ellipsometry measurements combined with AFM investigations were performed. The optical response was analyzed using an anisotropic Bruggeman effective medium approximation.
2：Sample Selection and Data Sources:
Five VO2 samples with thicknesses of 100, 200, 400, 600, and 800 nm were investigated. The samples were deposited by radio frequency sputtering using a metallic V target.
3：List of Experimental Equipment and Materials:
A commercial dual-rotating compensator ellipsometer (Woollam RC2-UI) and a Bruker Dimension Icon AFM system were used.
4：Experimental Procedures and Operational Workflow:
Ellipsometric measurements were performed at oblique angles of incidence from 25° to 65° in steps of 5°. Temperature-dependent measurements were performed in situ using a commercial heating stage.
5：5°. Temperature-dependent measurements were performed in situ using a commercial heating stage.
Data Analysis Methods:
5. Data Analysis Methods: The data was modeled using a Bruggemann effective medium approximation based on two parts, the insulating phase and the metallic phase, without resorting to any intermediate state.
独家科研数据包，助您复现前沿成果，加速创新突破
获取完整内容
