Transparent, Low‐Haze Aerogels With Tunable Plasmonic Photothermal Conversion for Smart Solar Windows

The conflict between optical transparency and thermal management in building windows remains a critical bottleneck for energy efficiency. Although aerogels offer exceptional thermal insulation, their passive nature fails to actively harness solar energy, particularly the near‐infrared (NIR) radiation, which constitutes nearly half of the solar influx. Here, we address this challenge by developing a functionalized silica aerogel film incorporating gold nanorods (GNRs). Unlike conventional spectrally‐selective coatings with fixed absorption bands, the GNRs enable tunable localized surface plasmon resonance in the NIR region, facilitating efficient photothermal conversion via non‐radiative relaxation of hot electrons. This design achieves a record photothermal performance: with only 5 nM GNRs, the aerogel film reaches over 81 °C under 1 sun illumination while maintaining a low haze of 12.5%. Notably, the GNRs are uniformly embedded within the nanonetwork, preserving the aerogel's thermal insulation, low density, and hydrophobicity. When applied as a window interlayer, the composite simultaneously provides solar harvesting and thermal shielding, capable of switchable “winter” or “summer” modes by simply reversing the window orientation, demonstrating a significant advancement over passive insulating aerogels. This work presents a paradigm shift from “energy‐saving” to “energy‐generating” windows, offering a feasible route toward actively harnessing solar energy for building thermal regulation.