Low‐Voltage Electrically Responsive Photonic Crystal Based on Weak‐Polar Colloidal System

Abstract Electrically responsive photonic crystal (ERPC) based on particle electrophoresis is a promising material to construct reflective color displays with low‐power‐consumption and antiglare advantages. However, the high driving voltages for the polar ERPC inevitably cause electrochemical reactions on the electrode, which decreases the stability and reversibility of electrical response. Here, a weak‐polar EPRC composed of hydrophobic SiO₂ particles, 1,2‐dichlorobenzene (DCB), and dioctyl sulfosuccinate sodium salt (AOT) is fabricated based on the charge separation by AOT reverse micelles and formation of highly charged particles in DCB. Compared to the polar ERPCs, the SiO₂/DCB‐AOT ERPC works at much lower voltages (0.5–1.7 V) and still possesses a wide color tuning range because the weak‐polar solvent applies less screening to the coulombic interactions. The low potential further renders the ERPC good capability against color fading in a strong field and long‐term reversibility during color switching, which addresses the critical concerns for its application in reflective displays.