Recent Advancements in Transition Metal Complexes as Triplet Emitters for Light-emitting Electrochemical Cells

This chapter explores recent advancements in ionic transition-metal complexes (iTMCs) for the development of light-emitting electrochemical cells (LECs). It begins by contextualising the evolution of lighting technology, emphasising the importance of energy-efficient solutions, such as solid-state lighting (SSL). Amongst SSL, LECs stand out due to their simple design, ease of manufacture and the use of mobile ions that improve charge injection. The discussion delves into the operational mechanisms of LECs, their fabrication techniques, device architectures and the influence of different materials in enhancing LEC performance, including the role of iTMCs based on metals, such as iridium, ruthenium, and copper. The chapter also discusses the challenges encountered during LEC development, such as efficiency, colour purity and operational stability, whilst emphasising the potential of iTMCs in overcoming these barriers. The chapter concludes by summarising key advancements and trends, showcasing the potential of iTMC-based LECs in developing efficient, durable and flexible lighting solutions.