Jin Xiaoyu, Hao Yuning, Su Zhuo, Li Ming, Zhou Guofu, Hu Xiaowen
College of Physics and Electronic Information, Yunnan Normal University, Kunming 650500, China.
SCNU-TUE Joint Research Lab of Device Integrated Responsive Materials (DIRM), National Center for International Research on Green Optoelectronics, South China Normal University, No. 378, West Waihuan Road, Guangzhou Higher Education Mega Center, Guangzhou 510006, China.
Polymers (Basel). 2023 Mar 31;15(7):1734. doi: 10.3390/polym15071734.
In this study, we present an electrically switchable window that can dynamically transmit both visible light and infrared (IR) light. The window is based on polymer stabilized cholesteric liquid crystals (PSCLCs), which are placed between a top plate electrode substrate and a bottom interdigitated electrode substrate. By applying a vertical alternating current electric field between the top and bottom substrates, the transmittance of the entire visible light can be adjusted. The cholesteric liquid crystals (CLC) texture will switch to a scattering focal conic state. The corresponding transmittance decreases from 90% to less than 15% in the whole visible region. The reflection bandwidth in the IR region can be tuned by applying an in-plane interdigital direct current (DC) electric field. The non-uniform distribution of the in-plane electric field will lead to helix pitch distortion of the CLC, resulting in a broadband reflection. The IR reflection bandwidth can be dynamically adjusted from 158 to 478 nm. The electric field strength can be varied to regulate both the transmittance in the visible range and the IR reflection bandwidth. After removing the electric field, both features can be restored to their initial states. This appealing feature of the window enables on-demand indoor light and heat management, making it a promising addition to the current smart windows available. This technology has considerable potential for practical applications in green buildings and automobiles.
在本研究中，我们展示了一种电可切换窗口，它能够动态地透射可见光和红外（IR）光。该窗口基于聚合物稳定胆甾相液晶（PSCLC），其置于顶板电极基板和底部叉指电极基板之间。通过在顶部和底部基板之间施加垂直交变电场，可以调节整个可见光的透过率。胆甾相液晶（CLC）织构将切换到散射焦锥态。在整个可见光区域，相应的透过率从90%降至15%以下。通过施加面内叉指直流（DC）电场，可以调节红外区域的反射带宽。面内电场的不均匀分布将导致CLC的螺旋节距畸变，从而产生宽带反射。红外反射带宽可在158至478nm范围内动态调节。可以改变电场强度来调节可见光范围内的透过率和红外反射带宽。去除电场后，这两个特性都可以恢复到初始状态。该窗口的这一吸引人的特性实现了按需进行室内光和热管理，使其成为现有智能窗口中有前景的补充。这项技术在绿色建筑和汽车的实际应用中具有相当大的潜力。
