Electrical Switching of Nematic Plasmonic Nanocolloids for Infrared Solar Gain Control

Abstract Controlling solar gain is essential to reduce the energy consumption by residential and commercial buildings, which are responsible for ≈40% of all energy generated globally. However, the dynamic control of solar gain in the near‐infrared that corresponds to ≈50% of the overall Sun's energy at the Earth's surface, separately from the visible spectral range has been a challenge, albeit commercial coatings provide passive control while retaining highly visible transmission. To address this problem, in this paper switchable silver colloids (SSCs) are demonstrated, colloidal analogs of the common silver coatings used for solar gain control. When dispersed in a nematic liquid crystal, orientations of such plasmonic silver nanoplates are controlled by ≈1 V low‐voltage electric fields, allowing for sub‐second switching of the near‐infrared‐based solar gain. Installed and retrofit products made from thin films of such nanoplate dispersions confined between glass and plastic substrates, respectively, exhibit electrically controlled infrared‐based solar gain while retaining high visible‐range transparency, low haze, and high color rendering index. This study's findings reveal a great potential of soft‐matter systems in addressing energy‐related problems.