“…Organic room temperature phosphorescence (ORTP) materials give light at room temperature and are promising candidates in many innovative applications, − such as bioimaging and diagnostics, − advanced encryption, , anticounterfeiting, optical recording and information storage, and organic light-emitting diodes (OLED). ,− It is well-known that the effective intersystem crossing (ISC) process between excited singlet state and triplet state and suppressed nonradiative decay are two important factors to generate excellent ORTP. One kind of strategy is used to boost spin–orbital coupling (SOC) for promoting the ISC process by introducing heavy atoms, heteroatoms, halogen bond incorporation, singlet fission, and intermolecular charge transfer (ICT). − The other strategies are used to suppress nonradiative relaxation of excited triplet state by constituting H-aggregation, , crystal engineering, − intermolecular interactions, ,, and host–guest systems. − The host–guest strategies have drawn significant attention in recent investigations due to the advantages of low cost, molecular diversity, simple preparation, and flexible modulation properties. − Basically, the host molecules can play the role of confining the guest molecules, thus suppressing the nonradiative relaxation. ,− At the same time, the host molecules are supposed to help the excimer transfer of guest molecules. − Along with the development of host–guest ORTP materials, molecule pairs possessing donor–acceptor properties show exceptional efficiency and luminescent lifetime. , H...…”