Flexible, controllable and angle-independent photoelectrochromic display enabled by smart sunlight management

Abstract

In this work, we present a newly designed photoelectrochromic smart windows (PECSW) comprising of a large-scale electrochromic device (ECD) and several integrated fiber-shaped dye-sensitized solar cells (FDSSCs). In this configuration, to avoid shading sunlight for each other, the FDSSCs twine around the ECD and serve as frames. Different from rigid planar solar cells, the FDSSCs are suitable to be integrated (series or parallel connection) to output desired power to drive the ECDs. More importantly, the angle dependence of the FDSSC's output on incident light is extremely low due to the unique cylindrical configuration, which brings convenience for the installation of the PECSW on the building external wall. Thanks to the high flexibility of the FDSSCs, the solar cells can be integrated with flexible ECDs for special applications. It was demonstrated that the PECSW can be directly driven by sunlight and the transmittance of the smart window can be adjusted by the light intensity. In addition, the PECSW also can be utilized as photoelectrochromic supercapacitor for energy storage and its reversible color variation can simultaneously monitor the level of stored energy. The FDSSCs based PECSW represents a new opportunity for emerging smart window technologies.