A fast-relaxation dye-doped cholesteric liquid crystal (DDCLC) smart window without any defects is prepared by the doping of a low bend elastic constants liquid crystal dimer 1″,7″-bis-(4-cyanobiphenyl-4′-yl)heptane (CB7CB). The ratio of the bend elastic constant to the twist elastic constant of the liquid crystals (LCs) is adjusted so that it equates to unity. The transient planar (TP) state and the planar (P) state are combined, so the relaxation time from the homeotropic (H) state to the P state is greatly. Moreover, the oily streaks of the P state are removed and the light scattering is lessened. The polarisation-independent DDCLC smart window switches between three states: the haze-free dark state, the high-haze dark state and the transparent state. The smart window can be used in situations where absorbed sunlight reduces room temperature and protects privacy.

通过掺杂低弯曲弹性常数液晶二聚体1″,7″-bis-(4-cyanobiphenyl-4′-yl)制备了一种无缺陷的快弛豫染料掺杂胆甾型液晶(DDCLC)智能窗庚烷 (CB7CB)。调整液晶(LC)的弯曲弹性常数与扭曲弹性常数的比值，使其等于一。瞬态平面（TP）态和平面（P）态结合在一起，所以从垂直（H）态到P态的弛豫时间很大。此外，P状态的油性条纹被去除并且光散射减少。与偏振无关的 DDCLC 智能窗在三种状态之间切换：无雾暗状态、高雾暗状态和透明状态。