Preparation of VO2-based solar cells. The VO2 smart window solar cells were assembled according to the structure in Figure 3. The PC plate was used as the light guider layer. The low reflective index medium , VO2-based film or nanoparticles with PDMS were adhered on the PC plate, and another PC plate was adhered on the low reflective index medium. After that, the silicon solar cells were adhered with PDMS. All of the cells were connected in parallel and the device was installed.