Recent Advances in Structural Design of Efficient Near‐Infrared Light‐Emitting Organic Small Molecules

Abstract Organic light‐emitting materials in the near‐infrared (NIR) region are important to realize next‐generation lightweight and wearable applications in bioimaging, photodynamic therapy, and telecommunications. Inorganic and organometallic light‐emitting materials are expensive and toxic; thus, the development of purely organic light‐emitting materials is essential. However, the development of highly efficient NIR light‐emitting materials made of organic materials is still in its infancy. Therefore, this review outlines molecular design strategies for developing organic small‐molecule NIR light‐emitting materials with high emission efficiency that can overcome the energy‐gap law to be applied to next‐generation wearable devices. After briefly reviewing the basic knowledge required for the NIR emission of organic molecules, representative high‐efficiency molecules reported over the past 5 years are classified according to their core moieties, and their molecular design, physical properties, and luminescence characteristics are analyzed. Further, the perspective and outlook regarding the development of next‐generation high‐efficiency NIR organic light‐emitting materials are provided.