Organic composite materials: Understanding and manipulating excited states toward higher light-emitting performance

Organic composite materials have been attracting extensive research interest for light-emitting applications. A wide variety of luminescent organic composite materials have been synthesized, which are of great significance for both the investigation of basic photophysics and the realization of high-performance photonic devices. Function-oriented syntheses of luminescent organic composite materials rely on the understanding and manipulating of molecular excited states. In this review, we focus on the discussion about the structure design and dynamics modulation of the electronic excited states in the organic composite materials. The excited-state structures and dynamics involve singlet/triplet levels, vibronic transition, charge transfer, and energy transfer, and so on, while the light-emitting behaviors include fluorescence, phosphorescence, persistent luminescence, electroluminescence, and lasing. We aim to give insight into the relationship between light-emitting properties and excited states of organic composite materials, which is beneficial for reaching higher tiers of design and applications of luminescent organic composite materials.