Recent Advances in Organic Room Temperature Phosphorescence of Triphenylamine-Based Doping Systems

The host–guest doping strategy has become one of the most effective approaches to realize pure organic room temperature phosphorescence (RTP). Crystalline small molecules can provide a rigid environment that restricts the molecular motion of luminescent guests, thus enhancing phosphorescence emission. Triphenylamine (TPA) is a classic crystalline small molecule matrix that, when doped with designed guest molecules, enables tunable RTP properties and diverse functionalities. These properties afford TPA-based doping systems with numerous applications in anticounterfeiting, bio-imaging, and multiple responsive sensing. In this concept, design strategies, luminescence mechanisms, and applications of TPA-based host-guest doping systems are summarized. Moreover, the future prospects of TPA-based RTP materials are proposed.