Ultraviolet‐Shielding and Low‐Voltage Polymer‐Dispersed Liquid Crystal Smart Windows Enabled by Rubrene Incorporation

Polymer‐dispersed liquid crystal (PDLC) films have attracted significant attention for smart‐window applications owing to their electrically tunable light‐scattering behavior; however, their practical implementation is hindered by high operating voltages and limited ultraviolet (UV) shielding capability. Here, we report a rubrene‐doped PDLC system that concurrently enhances electro‐optic performance and UV protection. Rubrene incorporation effectively lowers both threshold and saturation voltages, indicating improved driving efficiency. Dielectric analysis further reveals reduced dielectric loss and increased capacitance, consistent with suppressed mobile charge by rubrene dopant and enhanced dipolar interaction. In addition, the strong intrinsic UV absorption of rubrene significantly improves UV‐blocking performance, yielding shielding efficiencies of 96.6% in the OFF state and 67.2% in the ON state, both substantially higher than those of the undoped device. These results demonstrate that rubrene doping is a simple yet effective strategy for engineering multifunctional PDLC smart windows with enhanced electro‐optic efficiency and superior UV protection, offering strong potential for advanced optical material applications.