A novel method to improve phase transition of VO2 thermochromic films by Cs0.32WO3 nanoparticles

•The VO2/Cs0.32WO3 composite film were firstly prepared.•The Cs0.32WO3 shortened the phase transition response time of VO2 film.•The Cs0.32WO3 improves the solar-heat shielding ability of VO2 film.•The composite film can occur phase transition at 30 °C.•The composite film maintained good thermochromic properties.