Broadband Modulation, Self‐Driven, and Self‐Cleaning Smart Photovoltaic Windows for High Efficiency Energy Saving Buildings

Abstract Smart photovoltaic windows (SPWs) are an emerging green technology presenting energy‐saving by combining solar irradiance regulation and solar energy harvesting. The SPWs integrating extraordinary energy‐saving performance, stable and controllable operational mode, and diverse functionality are essential for devising high efficiency energy‐saving buildings (ESBs). However, the attainment of such features has yet to be realized in current iterations of SPWs. Herein, a conceptual demonstration of a split‐type broadband modulation, self‐driven, and self‐cleaning SPWs is presented by coupling a silicon solar cell with a multifunctional chromogenic unit (MCU) for creating highly efficient ESBs. Within the multilayer structured MCU, thermal‐responsive polymer stabilized liquid crystal (PSLC) and VO 2 @SiO 2 nanoparticles act as chromic component, enabling broadband light modulation. Thanks to the excellent electrothermal effect of indium tin oxide (ITO), the phase transition of PSLC and VO 2 @SiO 2 nanoparticles can be induced by the electrical power output generated by the silicon solar cell. Therefore, the transparency of SPWs can be manipulated according to the occupant's preference during the daytime. Moreover, a superhydrophobic SiO 2 coating provides SPWs with self‐cleaning capability which effectively reduces water resource consumption and eliminates the inconvenience of window cleaning, while providing occupants with a clear view even in complex weather conditions.