Electrochromic active matrix with plasmonic metasurfaces†

Abstract

Reflective pixels made by plasmonic metasurfaces and tuned by electrochromics exhibit significant potential to be used as flexible, polychromatic, electronic paper. This is attributed to their high reflectivity, low power consumption, and ultrathin dimensions. However, to date, only single pixels of electrochromics combined with plasmonics have been demonstrated. To make a graphical display, pixels in a matrix are required. A matrix configuration that has been successful for emissive displays such as liquid crystal displays (LCD) and organic light emitting-diodes (OLED) is the active matrix. Active matrix configurations consist of thin-film transistors (TFT) in an array where the transistors block unwanted signals. In this study, we demonstrate the suitability of a commercial, flexible TFT array as a substrate for depositing plasmonic metasurfaces in a red, green, and blue subpixel configuration. The conjugated polymer PProDOT-Me₂ can be directly polymerized onto selected pixels from a monomer solution and individual pixels can be controlled. We demonstrate the ability of the TFT array to function both in an electrochemical 3-electrode setup and as a 2-electrode flexible device.