Fig. 5: Durability test and application of the mask-inspired thermochromic perovskite window (MTPW).

a, b Optical performance (τ_lum,hot, τ_lum,cold and Δτ_sol) of the pristine thermochromic perovskite window (TPW) and the MTPW in the ambient environment. c Decay rate of Δτ_sol for the TPW and MTPW in the ambient environment. d Water repellence ability test for the pristine TPW and MTPW. e Pb concentration after soaking in water for the pristine TPW and MTPW. f Photographs of the flexible MTPW film in the cold and hot states. Red and blue arrows indicate heating and cooling processes, respectively. g Energy savings over a year obtained by using the MTPW, the tinted window film and the Low-e window film compared with a normal window. The energy consumption of the building in Energyplus simulation was collected, and the energy savings were calculated as the difference of energy consumption with normal windows and with other windows, divided by the energy consumption with normal windows. Source data are provided as a Source Data file.