A Universal Tandem Device of DC‐Driven Electrochromism and AC‐Driven Electroluminescence for Multi‐Functional Smart Windows

Abstract With the development of modern technology, the functions of smart windows are expected to be more abundant apart from reducing energy consumption. A viable and popular solution is to develop a versatile product. Here a multi‐functional tandem device enabled by ionic gels to form a smart glass that can be applied in manifold scenarios, is reported. The ionic gels successfully fulfill the multiple tasks of simultaneously being electrolytes, ion storage medium, as well as transparent electrodes, and help heighten the overall transparency of the devices. The novel tandem configuration simply consists of five stacking functional layers and is universal for DC‐driven electrochromic and AC‐driven electroluminescent sub‐devices. The newly‐developed devices demonstrate magnificent characteristics of high and tunable transparency (0–77%), selective infrared shielding ability, diversified displaying and decoration, excellent stability (3000 cycles), and even flexibility. Multifarious application scenarios of the structure in diversified device forms are proposed and presented. The proposed device architecture provides a facile methodology to fabricate functional devices and will provoke infinite novel ideas for developing the next‐generation smart windows.