Boosting Stimulated Emission via a Hydrogen‐Bonded Co‐Crystallization Approach in Molecular Crystals

Abstract

Stimulated emission of organic π‐conjugated molecule in solid state remains a significant challenge, mainly involving the mode of molecular stacking that invariably alters the photo‐physical processes. Herein, we successfully realized the stimulated emission in molecular crystals using a hydrogen‐bonded co‐crystallization strategy. Two hydrogen‐bonded co‐crystals, obtained from 1,4‐bis‐p‐cyanostyrylbenzene (CNDSB) and two types of co‐formers, can boost stimulated emission and show decent amplified spontaneous emission (ASE), whereas the parent CNDSB crystal is not SE‐active. Crystal structural analysis demonstrated that the co‐crystallization eliminated excimer formation. The resulting higher kr and shorter excited‐lifetime led to a larger stimulated‐emission cross section, which benefited to the occurrence of ASE. Simultaneously, the uniaxial arrangements along long axis of co‐crystal together contributed to highly polarized emission. This system presents very rare evidence of boosting stimulated emission by binary co‐crystallization, which enriches our insights into organic solid‐state lasers.