Fabrication and electrochemically-modulated optical properties of viologen and carbon dots hybrid glass composite films

Abstract

The electrochemical manipulation of optical properties will be essential in engineering next generation intelligent displays, wearable devices, and smart sensors. The rational design of electrochemically-modulated optical materials, especially those with multiple regulatory capacities, remains an unmet research challenge. We present here an optical composite, featuring multiple electrochemically-modulated properties, prepared through an electrochemistry-assisted hydrolytic crosslinking reaction between electroactive viologen and fluorescent carbon dots. Upon the electrochemical manipulation of the redox states of the viologen moieties, the resultant composite film exhibits interesting multistage regulated chromism with great color contrast, moderate switching rates, good coloration efficiency, and enhanced cycling stability. We demonstrate a unique sequential multistage regulated electrofluorochromism resulting from the inner filter effect and synergistic interplay between the electroactive viologen units and the fluorescent carbon dots. Furthermore, this optical composite reveals electrogenerated chemiluminescence with acceptable electrochemiluminescence intensity, attributed to the intrinsic behavior of carbon dots.