Electrically Switchable Amplified Spontaneous Emission from Liquid Crystalline Phase of an AIEE‐Active ESIPT Molecule
Electrically Switchable Amplified Spontaneous Emission from Liquid Crystalline Phase of an AIEE‐Active ESIPT Molecule
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DOI：
10.1002/adom.201902158
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发表时间：
2020-03
影响因子：
9
通讯作者：
Yusuke Tsutsui;Wanying Zhang;Samrat Ghosh;T. Sakurai;H. Yoshida;M. Ozaki;T. Akutagawa;S. Seki
中科院分区：
文献类型：
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作者：
Yusuke Tsutsui;Wanying Zhang;Samrat Ghosh;T. Sakurai;H. Yoshida;M. Ozaki;T. Akutagawa;S. Seki
利用有机分子作为激光介质，开发具有宽带可调性和大相干面积的下一代软物质光子学器件具有很大的潜力。虽然无反光镜激光在有机化合物的螺旋胆甾液晶（LC）相中得到了理论预测和实践证明，但最近对光学约束的研究主要集中在分子的硬晶相上。聚集诱导发射（AIE）和增强（AIEE）提供了凝聚态光放大的最佳分子体系之一，本文在室温（RT）向列LC中成功地耦合了AIEE活性和激发态分子内质子转移（ESIPT）。通过AIEE和ESIPT在LC相中的联合作用，抑制了浓度猝灭/自吸收的影响，实现了四能级的人口反转体系，从而使新设计的分子C5Ph - HBT以20 mJ cm-2的泵送能量阈值分散在RT LC基质中，产生了放大的自发发射（ASE）。此外，向列LC允许分子偶极子的取向响应于外部电场。因此，在RT下获得了荧光和ASE切换，证明了这些复合材料作为技术进步的“可切换”ASE介质的潜力。
Use of organic molecules as lasing media has much potential to develop next‐generation optical devices as soft‐matter photonics with wideband tunability and large coherence area. Although mirrorless lasing was theoretically predicted and practically demonstrated in helical cholesteric liquid crystalline (LC) phases of organic compounds, recent studies on optical confinement have been much focused into hard‐crystalline phases of the molecules. Aggregation‐induced emission (AIE) and enhancement (AIEE) provides one of the optimal molecular systems for light amplification in condensed phases, and herein AIEE activity and excited‐state intramolecular proton transfer (ESIPT) are successfully coupled in a room temperature (RT) nematic LC. Suppressing the effect of concentration quenching/self‐absorption and attaining four‐level system for population inversion by the combination of AIEE and ESIPT in LC phases, lead to the amplified spontaneous emission (ASE) from a newly designed molecule: C5Ph‐HBT dispersed in RT LC matrix with the pumping energy threshold of 20 mJ cm–2. Moreover, the nematic LC allows the orientation of the molecular dipoles in response to external electric fields. Hence, the fluorescence as well as the ASE switching is attained at RT, demonstrating the potential of these composite materials as “switchable” ASE media for technological progress.