Strategies toward Long-Life Light-Emitting Electrochemical Cells

This Minireview examines the operational lifetime of light-emitting electrochemical cells (LECs). Under continuous operation, both polymer-based LECs (PLECs) and ionic transition-metal complex (iTMC)-based LECs (iTMC-LECs) now exhibit a luminance half-life exceeding 1000 h. This improved performance was accomplished with several effective strategies aimed at optimizing the operating scheme, the material composition, and the device architecture. These strategies are presented in detail with PLECs as an example. iTMC-LECs are also highlighted owing to their excellent stress stability with regards to both luminance and operating voltage. The survey of literature data points to clear trends, as well as some unexpected results in LECs stressed for an extended period. Major challenges still exist, but long-lasting LECs are possible when the proven strategies are combined with innovative materials and device design.