Light-Emitting Devices Based on Electrochemiluminescence Gels

Electrochemiluminescence (ECL) is a self-emission of light from electrochemically excited luminophores via a series of redox reactions. Over the past decade, light-emitting devices based on gel-phase ECL active materials, i.e., gel electrolyte composites (referred to as ECL gels) containing an ECL luminophore, electrolyte, and network matrix, have attracted considerable attention as a complementary device platform to conventional electroluminescent devices for low-cost printable displays and solid-state light sources. Although the ECL phenomenon is extensively exploited in analytical diagnostics and sensing, the development of printable and fast-response gel-type luminescent materials may further expand the potential application of ECL in solid-state flexible, bendable, and stretchable light-emitting devices. This review summarizes the operation mechanisms of ECL-based light-emitting devices, ECL emitters and electrolytes, engineering strategies for obtaining printable high-strength/high-conductivity ECL gels, and emerging applications of gel-type ECL devices.