Chiral materials and mechanisms for circularly polarized light-emitting diodes

Circularly polarized (CP) light-emitting diodes (LEDs) hold great potential for next-generation technologies, from efficient photonic to room-temperature quantum devices. Chiral materials enable the generation of CP electroluminescence in LEDs through several different mechanisms, depending on the choice of material and device architecture. Here we summarize the mechanisms that give rise to CP electroluminescence in state-of-the-art materials, including organic small molecules, polymers, inorganic complexes and hybrid halide perovskites. We explore how the device architecture can be used to control the chiroptical properties and device performance, and suggest improvements to maximize the efficiency and dissymmetry factor of future CP LEDs. Chiral materials and related mechanisms are reviewed, with a focus on applications for circularly polarized light-emitting diodes.