Amplified Spontaneous Emission from Organic Phosphorescence Emitters

作者：Guo Zu, Shuai Li, Jingping He, Haihua Zhang, Hongbing Fu · 发表于：The Journal of Physical Chemistry Letters · 年份：2022 · DOI：10.1021/acs.jpclett.2c01379 · 被引用次数：19 · 研究领域：Organic Light-Emitting Diodes Research、Luminescence and Fluorescent Materials、Perovskite Materials and Applications

Organic gain materials (OGMs) currently used in organic lasers and optical amplifiers are focused on singlet-fluorescence materials, while triplet-phosphorescence-based OGMs have hardly been developed yet. Herein, we report a novel pure organic phosphorescence gain molecule (SBP) for optical amplification by stimulated emission from triplet states. The introduction of the benzophenone carbonyl group and sulfur atoms increases the spin orbit coupling constant of SBP, which accelerates the intersystem crossing (ISC) and phosphorescence processes. Experimental and theoretical results verify that the formation of the H-type dimer aggregate decreases the fluorescence radiation rate while accelerating the ISC rate, also enhancing the phosphorescence emission of SBP. Doping SBP molecules into a PMMA matrix can stabilize triplet excitons, yielding the maximum phosphorescence quantum yield of 18.9%. We realized triplet phosphorescent amplified spontaneous emission (ASE) at 557 nm from 30.0 wt % SBP@PMMA samples. Our results provide a novel strategy to develop triplet phosphor OGMs.