Transparent Electrode‐Free Light‐Emitting Devices Exploiting Ion Transport‐Controlled Electrochemiluminescence

Abstract Transparent electrode‐free light‐emitting devices are presented that exploit electrochemiluminescence (ECL). These devices feature two side‐by‐side noble metal electrodes connected by an ECL active layer. The significance of bulk ion‐transport characteristics is investigated within the ECL active layer in producing uniform planar emission from the device. These characteristics can be enhanced by simply increasing the ECL active layer thickness or adding an ion gel electrolyte layer on top of the ECL active layer. The use of only electrochemically stable noble metal electrodes results in an operational lifetime exceeding 10 h, which is the longest lifetime reported for ECL‐based light‐emitting devices to date. The device structure based on ECL does not require transparent electrodes, allowing for increased flexibility when designing devices for future light‐emitting device applications.