Low‐Voltage Tunable Cholesteric Phase Liquid Crystal Broadband Reflective Films for Energy‐Efficient Smart Windows

ABSTRACT Cholesteric‐phase liquid crystal (CLC) film's wide wave reflection characteristics enable it to be widely used in display, smart windows, and other fields. Usually, the reflection spectra range of CLC films is narrow and difficult to be switched as needed, or high external field voltages are applied to adjust the reflection band. In this study, we optimized the composition and structure of polymerizable monomers with negative LC as the matrix and prepared a CLC film with a wide reflection band (about 1000 nm) that can be adjusted at low voltage (~32 V), which is significantly lower than previous reports (> 80 V). In addition, the cyclic electric field driving stability and infrared‐light shielding performance of the CLC films were also investigated in detail. It was found that within the same infrared exposure time, the temperature increase of the CLC film under applying voltage was obviously lower than that of the CLC film without applied voltage. Therefore, our research results may contribute to the development of high‐performance intelligent liquid crystal films and promote the application of energy‐saving smart windows.