Recent advances in VO2-based thermochromic composites for smart windows

Abstract

Vanadium dioxide (VO₂) is a well-known thermochromic material since it exhibits a notable optical variation in the near-infrared region from transmitting to reflecting upon the semiconductor-to-metal phase transition (SMT). This distinctive character makes it attractive in thermochromic smart window applications. However, the development of VO₂ in energy-efficient windows is hindered by high transition temperature (T_c), low luminous transmittance (T_lum), small solar modulation efficiency (ΔT_sol), the uncertainty of durability, and the lack of color change. To solve the above problems, researchers have made great efforts in VO₂-based composites and found that using composite materials with different fabrication methods revealed the most satisfactory performance. This review focuses on the use of composite structures (core–shell nanostructure, hybridization, multilayer structure, etc.), and we discuss preparation methods, material structures, and prospects of VO₂-based thermochromic composites for smart windows.