Efficient organic room-temperature phosphorescence in both solution and solid states

Organic room-temperature phosphorescence (RTP) materials possess immense potential for a variety of applications. However, conventional RTP materials face substantial problems, such as no phosphorescence in ambient solution, and inefficient amorphous films and electroluminescence devices. To address these issues, intrinsic RTP emitters can display efficient RTP in various states and achieve multiple desired properties through the same molecule. In this work, dendrimers are first used to design of efficient intrinsic RTP materials by incorporating dendrons as triplet regulators to facilitate effective spin-orbit coupling, intersystem crossing, and triplet radiative transitions that exhibit a significant transformation from delayed fluorescence to intrinsic RTP in different states. The dendrimers exhibit long phosphorescence lifetime within milliseconds in ambient solution, photoluminescence quantum yield of 98% in doped films, and substantially high external quantum efficiency of 25.1% in the organic electroluminescence devices. Moreover, by regulating the triplet characteristics of the dendrimers, the dendrimers display up-converted anti-Kasha dual-RTP emissions and an ultra-long afterglow lifetime within seconds in rigid polymer matrixes. These results pave the way for the development of novel RTP systems for versatile optoelectronic applications.