Single crystals are the footstone for the development of modern microelectronics and solid-state electronics, and optoelectronic techniques. Similar to inorganic single crystal semiconducting materials (e.g., silicon), organic single-crystal semiconductors with nearly perfect spatial arrangement and extremely high chemical purity are endowed with improved physical properties over their polycrystalline counterparts in various electronic and optoelectronic devices. Over the past two decades, key performance breakthrough has been achieved in organic electronics by harnessing the unique properties of organic single crystals. Nevertheless, growth of large-scale organic single-crystal films (OSCFs) has not been well demonstrated so far. The reason is that molecules in organic crystals band together via weak van der Waals forces (<10 kcal mol-1), external interferences like the unevenness of substrate surface and the instable mass transport in fluid, would cause multiple nucleation and disorder crystal growth.
To address this problem, Prof. Jiansheng Jie et al. from Institute of Functional Nano and Soft Materials (FUNSOM), Soochow University developed a breakthrough strategy, orientation filter funnel, to fabricate large-area OSCFs with well-aligned, singly orientated crystals. By rationally designing solvent wetting/dewetting patterns on the substrate, this approach can produce seed crystals with the same crystallographic orientation and then maintain epitaxial growth of these crystals, enabling the formation of large-area OSCFs. As a result, this unique concept for crystal growth not only enhances the average mobility of organic film by 4.5-fold but also improves its uniformity of electrical properties, with a low mobility variable coefficient of 9.8%, the new lowest record among organic devices. The method offers a general and scalable route to produce OSCFs toward real-word electronic applications.
The paper has been reported and highlighted by a number of media, including MIT Technology Review, Semiconductor Industry Network, Microelectronics Manufacturing, Sohu, Sina, NetEase News and so on.
Author information: Wei Deng, Hemeng Lei, Xiujuan Zhang, Fangming Sheng, Jialin Shi, Xiali Zhang, Xinyue Liu, Souren Grigorian, Xiaohong Zhang, Jiansheng Jie*
Link to paper: https://onlinelibrary.wiley.com/doi/abs/10.1002/adma.202109818
Editor: Danting Xiang