Manipulating the Charge Transfer Absorption for Narrowband Light Detection in the Near-Infrared
Manipulating the Charge Transfer Absorption for Narrowband Light Detection in the Near-Infrared
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DOI：
10.1021/acs.chemmater.9b02700
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发表时间：
2019-11-26
影响因子：
8.6
通讯作者：
Vandewal, Koen
中科院分区：
文献类型：
--
作者：
Kaiser, Christina;Schellhammer, Karl Sebastian;Vandewal, Koen
在电子给予分子（供体，D）和电子接受分子（受体，A）之间的界面处的电荷产生和复合过程由分子间电荷转移（CT）状态介导。由于有机光伏和光电探测器件依赖于D-A界面，因此对控制CT状态特性的分子和形态学方面的理解至关重要。在本文中，我们合成了一系列新的双（硫代）吡喃叉供体分子，并显示了如何在D-C-60共混物中的分子结构和能级的相互作用影响CT吸收截面的线形。通过合理设计分子2，2 '，6，6'-四-（2-甲基噻吩基）-4，4 '-联噻喃亚基，当与C-60混合时，我们实现了比文献已知的分子2，2'，6，6 '-四苯基-4，4'-联噻喃亚基强2倍的CT吸收峰。这种新材料混合物的低CT态能量与相对较强的CT吸收相结合，通过制造近红外腔增强窄带探测器来利用。光电探测器覆盖了810至1665 nm的波长范围，线宽在30至50 nm之间。
Charge generation and recombination processes at interfaces between electron donating (donor, D) and accepting molecules (acceptor, A) are mediated by intermolecular charge-transfer (CT) states. Since organic photovoltaic and photodetecting devices rely on D-A interfaces, an understanding of the molecular and morphological aspects governing CT state properties is crucial. In this paper, we synthesize a novel series of bi(thio)pyranylidene donor molecules and show how the interplay of molecular structure and energy levels in a D-C-60 blend affect the line shape of the CT absorption cross section. By rationally designing the molecule 2,2',6,6'-tetra-(2-methylthienyl)-4,4'-bithiopyranylidene, we achieve a 2 times stronger CT absorption peak than the literature-known molecule 2,2',6,6'-tetraphenyl-4,4'-bipyranylidene when blended with C-60. The low CT state energy combined with relatively strong CT absorption of this new material blend is exploited by fabricating near-infrared, cavity enhanced narrowband detectors. The photodetectors cover an impressive wavelength range from 810 to 1665 nm with line widths between 30 and 50 nm.