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 degrees 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.