Fast, highly chromatic, electrically responsive photonic crystal inks for displays

Electrically responsive photonic crystals (ERPCs), a kind of electrophoretic color display material with significant market potential, feature a simple preparation process and allow for voltage-adjustable color transformation. However, their excessive electrical response time and limited color chromaticity have hindered their practical applications. In this context, this study presents a straightforward method to create ERPC devices based on SiO2/sodium dodecyl benzene sulfonate (SDBS)/acidified carbon nanotubes (ACNTs), which can switch color states reversibly with electric field application. During this process, the anion groups provided by SDBS are introduced into the slipping layer of microspheres resulting in high surface charges for colloidal particles, while the black material ACNTs enhance electronic ink coloring by absorbing incoherent scattered light. The high surface charge further improves the response rate and enhances stability and reversibility. Compared to previously reported ERPCs, the SiO2/SDBS/ACNT-based ERPC exhibits a shorter response time and higher chromaticity, laying a foundation for reflective displays.