COMMUNICATION 1701861 (1 of 7) www.small-journal.com small NANO MICRO © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Regular Aligned 1D Single-Crystalline Supramolecular Arrays for Photodetectors Yun Liu, Jiangang Feng, Bo Zhang, Yuchen Wu,* Yong Chen,* and Lei Jiang Dr. Y. Liu Beijing National Laboratory for Molecular Sciences (BNLMS) Key Laboratory of Green Printing, Institute of Chemistry Chinese Academy of Sciences Beijing 100190, P. R. China Dr. Y. Liu, Dr. J. G. Feng, Prof. L. Jiang University of Chinese Academy of Science Beijing 100049, P. R. China Dr. J. G. Feng, Dr. Y. C. Wu, Prof. Y. Chen, Prof. L. Jiang Key Laboratory of Bio-Inspired Materials and Interfacial Science Technical Institute of Physics and Chemistry Chinese Academy of Sciences Beijing 100190, P. R. China E-mail: wuyuchen@iccas.ac.cn; chenyong@mail.ipc.ac.cn Dr. B. Zhang, Prof. L. Jiang Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of Ministry of Education Beijing Key Laboratory of Bio-Inspired Energy Materials and Devices School of Chemistry Beihang University Beijing 100191, P. R. China DOI: 10.1002/smll.201701861 Semiconducting supramolecular mate- rials exhibit efficient exciton generation, remarkable light sensitivity, and light harvesting, [1–4] thus are ideal compo- nents in applications such as phototran- sistors, [5] field-effect transistors, [6] solar cells, [7,8] and photovoltaic devices. [9,10] Distinguished from polycrystals, single crystals possess long-range order, few structural defects, and eliminated grain boundary, which provide considerable potential for achieving excellent device performance. [11–17] Solution-processed semiconducting materials have promising advantages in terms of low-cost, large area, and flexibility. [15,18–22] Therefore, various patterning methods have been developed such as drop casting, hollow pen writing, and inject printing. [23–28] The micro/nano- structure arrays could be obtained through these solution method; however, it is hard to control the molecular orientation in micro/nanostructures due to the poorly regulated fluid flow and fast solvent evapo- ration process. For conventional solution patterning techniques, miniaturized liquid droplets or thin films are located with predetermined patterns followed by evaporation of solvents, dewetting, nucleation, and growth. The dewetting process is dominated by isotropic and random capillary flow, thus inducing random nucleation and growth of crystals at gas–liquid–solid three-phase contact line (TCL). To obtain regular patterned single-crystals with fine morphology and molecular packing, unidirectional driving force is required to conquer the coffee ring effect and regulate the dewetting dynamics, fluid flow, mass transport, and crystallization process. Bao and co-workers demonstrated a fluid-enhanced crystal engineering strategy by harnessing the unidirectional shearing force to regulate the fluid flow in solution process, yielding large-scale single-crystalline thin films. [29] This method have succeed in guiding the unidi- rectional dewetting process at the macroscale and achieving an unprecedented mobility of the thin film devices. In this work, we demonstrate an efficient and facile solution- processing method for patterning organic single-crystalline microstructures. An asymmetric-wettability micropillar tem- plate with lyophobic tops and lyophilic sidewalls was intro- duced to controlling the dewetting dynamics of molecule solutions. Owing to the lyophobic tops, the liquid film is con- fined in the gaps between each two micropillars, generating Solution-processed semiconductor single-crystal patterns possess unique advantages of large scale and low cost, leading to potential applications toward high-performance optoelectronic devices. To integrate organic semi- conductor micro/nanostructures into devices, various patterning techniques have been developed. However, previous patterning techniques suffer from trade-offs between precision, scalability, crystallinity, and orientation. Herein, a patterning method is reported based on an asymmetric-wettability micro- pillar-structured template. Large-scale 1D single-crystalline supramolecular arrays with strict alignment, pure crystallographic orientation, and precise position can be obtained. The wettability difference between tops and sidewalls of micropillars gives rise to the confinement of organic solutions in discrete capillary tubes followed by dewetting and formation of capillary trailing. The capillary trailing enables unidirectional dewetting, regulated mass transport, and confined crystal growth. Owing to the high crystal- linity and pure crystallographic orientation with Pt atomic chains parallel to the substrate, the photodetectors based on the 1D arrays exhibit improved responsivity. The work not only provides fundamental understanding on the patterning and crystallization of supramolecular structures but also develops a large-scale assembly technique for patterning single-crystalline micro/ nanostructures. Photodetectors Small 2017, 1701861