Boosting the Efficiency of Organic Solid‐State Lasers by Solvato‐Tailored Assemblies

The photophysical properties of pure organic materials in solid-state are widely related to the crystal's arrangements. Herein, 4,6-bis((E)-4-(dibenzothiophene)styryl)-5(ethoxycarbonyl)-2,2-difluoro-2H-1,3,2-dioxaborinin-1-ium-2-uide (BBSF) is employed as a mode molecule to explore the relationship between molecular arrangement and performance. Three elegant crystals (solvent-free-)-aggregation of EA-crystal, solvent+aggregations of CB-crystal, and FB-crystal) are obtained by solvato-tailored strategy. Detailed single crystal structures and photophysical data reveal that all the three crystals adopt a J-type aggregation model. EA-crystal does not involve solvent molecular while the CB- and FB-crystals involve chlorobenzene (CB) arid fluorobenzene (FB) molecules, respectively. Solvent molecules can effectively separate the two columns of BBSF molecules, resulting in high brightness emission. Laser behaviors indicate that the solvent-microcrystals display higher brightness, lower threshold, as well as higher quality factor than solvent-free-microcrystal due to the weakened bimolecular exciton annihilation process. This strategy not only paves an intriguing way to the construction and preparation of pure organic J-aggregation laser materials but also offers a guideline for suppressing bmEA process through introducing solvent molecules.