Tungsten-doped vanadium dioxide thin films on borosilicate glass for smart window application

► Tungsten-doped VO2 (W-VO2) films with different annealing conditions were fabricated. ► W-VO2 films were found to exhibit a semiconductor-metal transition at 34 °C. ► The W atoms have been successfully doped into VO2 film and exist as W6+ in the films. ► W-VO2 films possess excellent infrared switching efficiency, i.e. 33%.