Modulation of the Phase Transition Behavior of VO2 Nanofilms by the Coupling of Zr Doping and Thickness-Dependent Band Gap

Vanadium dioxide (VO2) is a representative thermochromic material because of its unique first-order metal–insulator transition (MIT) at 68 °C. However, reducing the MIT temperature and clarifying the modulation relationship between Zr doping concentration and the MIT temperature of VO2 are extremely challenging. Here, we combine first-principles calculations and thermodynamic models to modulate the phase transition behavior of VO2 nanofilms by coupling Zr doping and the thickness-dependent band gap. It is observed that Zr doping causes changes in the structural stability and electronic and optical properties of VO2, which lead to a decrease in the MIT temperature. Comparing the calculated results with the experimental results, we clarify that the Zr doping concentration and MIT temperature of VO2 have a linear modulation relationship. These findings provide a concept for modulating the phase transition of VO2 nanomaterials.