Ultrafast Dynamics and Photoresponse of a Fungi‐Derived Pigment Xylindein from Solution to Thin Films
Ultrafast Dynamics and Photoresponse of a Fungi‐Derived Pigment Xylindein from Solution to Thin Films
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真菌衍生色素 Xylindein 从溶液到薄膜的超快动力学和光响应
DOI：
10.1002/chem.202005155
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Fang, Chong
中科院分区：
文献类型：
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作者：
Krueger, Taylor D.;Giesbers, Gregory;Van Court, Ray C.;Zhu, Liangdong;Kim, Ryan;Beaudry, Christopher M.;Robinson, Seri C.;Ostroverkhova, Oksana;Fang, Chong
近年来，有机半导体材料因其无毒、低成本和可持续性而获得了发展势头。木lindein是一种由生长在腐烂木材上的真菌分泌的具有显著光稳定性的色素，其相对较强的电子性能是通过π -π堆叠和促进电荷传输的氢键网络实现的。本文利用飞秒瞬态吸收光谱和近红外探针揭示了分子内质子转移反应的快速激发态。构象运动可能导致圆锥形相交，猝灭了单体状态下的荧光。在浓溶液中，由于准分子的形成，新生聚集体表现出更快的激发态寿命，这被木lindein薄膜的准分子→电荷转移激发态吸收带证实，从而限制了其光电性能。因此，用支链烷基延长木lindein侧链可能会阻碍准分子的形成，并改善天然衍生材料的光电性能。
Organic semiconductor materials have recently gained momentum due to their non‐toxicity, low cost, and sustainability. Xylindein is a remarkably photostable pigment secreted by fungi that grow on decaying wood, and its relatively strong electronic performance is enabled by π–π stacking and hydrogen‐bonding network that promote charge transport. Herein, femtosecond transient absorption spectroscopy with a near‐IR probe was used to unveil a rapid excited‐state intramolecular proton transfer reaction. Conformational motions potentially lead to a conical intersection that quenches fluorescence in the monomeric state. In concentrated solutions, nascent aggregates exhibit a faster excited state lifetime due to excimer formation, confirmed by the excimer→charge‐transfer excited‐state absorption band of the xylindein thin film, thus limiting its optoelectronic performance. Therefore, extending the xylindein sidechains with branched alkyl groups may hinder the excimer formation and improve optoelectronic properties of naturally derived materials.