A Highly Transparent Photo‐Electro‐Thermal Film with Broadband Selectivity for All‐Day Anti‐/De‐Icing

Abstract A photo‐ and electro‐thermal film can convert sunlight and electricity into heat to solve icing problems. Combination of them provides an efficient strategy for all‐day anti‐/de‐icing. However, only opaque surfaces have been reported, due to the mutual exclusiveness between photon absorption and transmission. Herein, a highly transparent and scalable solution‐processed photo‐electro‐thermal film is reported, which exhibits an ultra‐broadband selective spectrum to separate the visible light from sunlight and a countertrend suppress of emission in longer wavelength. It absorbs ≈ 85% of invisible sunlight (ultraviolet and near‐infrared) for light‐heat conversion, meanwhile maintains luminous transmittance > 70%. The reflection of mid‐infrared leads to low emissivity (0.41), which further preserves heat on the surface for anti‐/de‐icing purpose. This ultra‐broadband selectivity enables temperature elevation > 40 °C under 1‐sun illumination and the mutual support between photo‐thermal and electro‐thermal effects contributes to > 50% saving of electrical consumption under weak solar exposure (0.4‐sun) for maintaining unfrozen surfaces at −35 °C environment. The reverberation from photo‐electro‐thermal and super‐hydrophobic effects illustrates a lubricating removal of grown ice in short time (< 120 s). The self‐cleaning ability and the durability under mechanical, electrical, optical, and thermal stresses render the film stable for long‐term usage in all‐day anti‐/de‐icing applications.