Guo Junfeng, Zeng Yan, Zhen Yonggang, Geng Hua, Wang Zongrui, Yi Yuanping, Dong Huanli, Hu Wenping
National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Angew Chem Int Ed Engl. 2022 Jul 11;61(28):e202202336. doi: 10.1002/anie.202202336. Epub 2022 May 17.
Rare studies of cocrystal engineering have focused on improving carrier mobility of organic semiconductors mainly because of the generation of ambipolarity, the alteration of the charge carrier polarity or the reduction of electronic couplings. Herein, we utilize indolo[2,3-a]carbazole (IC) as the model compound and 2,6-diphenylanthraquinone (DPAO) and 9-fluorenone (FO) as the coformers to construct IC2-DPAO and IC-FO cocrystals with 2 : 1 or 1 : 1 ratios, respectively, through hydrogen bonds and donor-acceptor interactions. Interestingly, the more appropriate packing structure, possessing not only enhanced electronic couplings but also increased intermolecular distances, is achieved in IC2-DPAO, which shows an improved carrier mobility of 0.11 cm V s by four orders of magnitude relative to the IC crystal. These results suggest that non-equal ratio cocrystal engineering opens up the possibility to develop organic semiconductors with enhanced charge transport behaviors.
关于共晶工程的研究很少，主要是因为产生双极性、改变电荷载流子极性或减少电子耦合，这些研究主要集中在改善有机半导体的载流子迁移率上。在此，我们以吲哚并[2,3-a]咔唑（IC）作为模型化合物，以2,6-二苯基蒽醌（DPAO）和9-芴酮（FO）作为共晶形成物，分别通过氢键和供体-受体相互作用构建比例为2:1或1:1的IC2-DPAO和IC-FO共晶。有趣的是，在IC2-DPAO中实现了更合适的堆积结构，不仅具有增强的电子耦合，而且分子间距离增加，相对于IC晶体，其载流子迁移率提高到0.11 cm² V⁻¹ s⁻¹，提高了四个数量级。这些结果表明，非等比例共晶工程为开发具有增强电荷传输行为的有机半导体开辟了可能性。
