Developing an Analysis Procedure and Dispersion Model for Pristine and W-Doped VO2 Thin Films Using Density
Benedict S Morris1,2, Zahra Shayegan1, Daniel Koch1
1Institut National de la Recherche Scientifique Centre Énergie Matériaux et Télécommunications, 1650 Boulevard Lionel-Boulet, Varennes J3X 1P7, Canada.
ACS Applied Materials & Interfaces
|December 2, 2024
Summary
A new method accurately determines optical properties of vanadium dioxide (VO2) thin films. This analysis reveals tungsten (W) doping primarily impacts VO2
Area of Science:
- Materials Science
- Condensed Matter Physics
- Nanotechnology
Background:
- Vanadium dioxide (VO2) exhibits a semiconductor-to-metal phase transition near room temperature, crucial for smart materials.
- The optical properties of VO2 are highly sensitive to synthesis methods and doping, necessitating accurate characterization.
- Tungsten (W) doping lowers the transition temperature, impacting VO2's utility in advanced technologies.
Purpose of the Study:
- To present a universal analysis procedure for accurately determining the optical properties of pristine VO2 thin films.
- To develop a novel dispersion model for VO2 using density functional theory.
- To investigate the impact of W-doping on VO2 optical properties.
Main Methods:
- Development of a VO2-specific dispersion model using density functional theory.
- Application of the dispersion model to analyze optical properties of pristine and W-doped VO2 thin films.
- Comparison of optical absorption spectra below and above the transition temperature.
Main Results:
- The developed dispersion model accurately describes four contributions to VO2 optical absorption between 2 and 5 eV.
- The analysis procedure was validated using literature data and applied successfully to W-doped VO2 films.
- W-doping predominantly affects near-infrared optical properties in the low-temperature phase, increasing absorption below 1 eV.
Conclusions:
- A robust method for characterizing VO2 optical properties has been established.
- The study provides a direct comparison of pristine and W-doped VO2 optical properties.
- W-doping significantly modifies the optical absorption edge and near-infrared response of VO2.
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