A flexible colored polymer-dispersed liquid crystal smart windows with excellent near-infrared shielding performance

Heat management and color appearance are the key issues for the application of smart windows. Herein, a vibrant colored energy-saving polymer-dispersed liquid crystal (PDLC) film has been designed by combining dye-doping and the application of a heat shielding electrode. The LC droplet size could be varied by tuning the content of the dye. PDLC films featuring a low Disperse Orange 25 Azo dye concentration (0.06%) achieving an impressive contrast ratio of up to 101.5 with the transmittance reaching 79.17% at on state. Furthermore, indium tin oxide (ITO) and aluminum-doped zinc oxide (AZO) were chosen as the conductive layer materials, and the heat shielding properties of ITO and AZO/Ag/ITO (AAI) films were applied to PDLC devices and comparatively investigated. The AAI-based devices exhibited temperature reductions of 2 °C and 4 °C compared to the ITO-based devices at off and on states, respectively. This highlights the remarkable heat shielding performance and energy-saving capability of AAI-PDLC devices, as well as good flexibility and cycle stability. These AAI-based colored PDLC films exhibit substantial potential for smart window applications especially in buildings and automotive industry.