Room temperature phosphorescence materials based on small organic molecules: Design strategies and applications

Abstract Room‐temperature phosphorescence (RTP) materials have attracted significant attention due to their applications in various fields such as information storage and encryption, organic light‐emitting diode (OLED), sensing, lighting and display, biological imaging, and photodynamic therapy. Traditionally, RTP materials can be efficiently developed using inorganic systems with noble metals or rare earth elements. Recently, many efforts have been devoted to the development of RTP materials based on small organic molecules. The strategies to construct RTP materials include hydrogen bonding, heavy atom effect, n –π* transitions, π–π stacking, donor–acceptor effect, and host–guest doping. Herein, we summarize the recent examples of RTP materials based on small organic molecules primarily focusing on their design strategies and properties. Moreover, their promising applications in information encryption, OLED, as well as bio‐imaging and phototherapy are discussed. The challenges and perspectives are given to provide inspiration toward the future development of organic RTP materials.