Abnormal homodirectional responses of magneto-phosphorescence and magneto-fluorescence in organic phosphorescent crystals under third-component doping

Abstract

Molecular doping has emerged as a promising method for enhancing the performance of organic phosphorescent crystals. In this work, through incorporating third component molecules with inactive phosphorescence into binary phosphorescence crystals, ternary phosphorescent crystals with afterglow visible to the naked eye are constructed via co-crystallization of three components. Energy transfer between the third-component and ternary crystals is motivated by the incorporation of the third-component, where third-component with an optimized concentration can facilitated an 11-fold increase in phosphorescence lifetime of the ternary crystal. Notably, the phosphorescence is contributed from the radiative recombination of triplet excitons in the third-component, leading to abnormal homodirectional responses of magneto-phosphorescence and magneto-fluorescence in phosphorescence crystals. Furthermore, under the stimuli of external magnetic fields, the magneto-phosphorescence and magneto-fluorescence process also compete with each other, and the competition is tightly dependent on the external light intensity. Overall, this study forecasts a phosphorescence design method based on third-component incorporation, which also provide an insightful understanding of magneto-phosphorescence effect in organic ternary phosphorescent crystals.