Single-Crystal Organic Nanowire Electronics by Direct Printing from Molecular Solutions

A one-step process to generate single-crystal organic nanowire arrays using a direct printing method (liquid-bridge-mediated nanotransfer molding) that enables the simultaneous synthesis, alignment, and patterning of nanowires from molecular ink solutions is reported. Using this method, many single-crystal organic nanowires can easily be synthesized by self-assembly and crystallization of organic molecules within the nanoscale channels of molds, and these nanowires can then be directly transferred to specific positions on substrates to generate nanowire arrays by a direct printing process. The position of the nanowires on complex structures is easy to adjust, because the mold is movable on the substrates before the polar liquid layer, which acts as an adhesive lubricant, is dried. Repeated application of the direct printing process can be used to produce organic nanowire-integrated electronics with two- or three-dimensional complex structures on large-area flexible substrates. This efficient manufacturing method is used to fabricate high-performance organic nanowire field-effect transistors that are integrated into device arrays, inverters, and phototransistors on flexible plastic substrates.K.S.P. and B.C. contributed equally to this work. This work was supported by the National Research Foundation (NRF) grant funded by the Korea government (MEST) (No. 2012-0008678), and the Global Frontier R&D Program on the Center for Multiscale Energy System (No. 2011-0031562), Nano.Material Technology Development Program (2012M3A7B4034985), and a Global Ph. D. Fellowship Program (No. 2011-0007507) funded by the National Research Foundation. We thank the Korea Basic Science Institute (KBSI) for allowing us to use their EF-TEM