Molecular Materials with Short Radiative Lifetime for High-Speed Light-Emitting Devices

Summary Optical communication and interconnects utilize high-speed light sources for information transmission. The modulation frequency of light-emitting devices operating through spontaneous emission is fundamentally limited by the material intrinsic radiative lifetime. In this perspective, we examine the radiative lifetime of different materials and identify the superradiant molecular J aggregates as a promising class of materials for high-speed light-emitting devices. These molecular aggregates are relatively unexplored for electroluminescent devices and can have short radiative lifetime on the order of 10 ps while maintaining high photoluminescence quantum yield. The relation between intermolecular interactions, molecular packing geometry, and radiative lifetimes is presented theoretically in the context of Frenkel excitons and is corroborated with experimental examples. We further demonstrate the potential of designing superradiant materials through molecular engineering. We believe that these superradiant molecular materials will open up new opportunities in the fabrication of efficient and high-speed light-emitting devices.