A simple and rapid formation of wet chemical etched silicon nanowire films at the air–water interfaceElectronic supplementary information (ESI) available: ESI 1: (S1) the destruction of a thin film of Si NWs, (S2) photo images related to Fig. 3(a) and (b), (S3) modeling of the surface free energy potential well, (S4) 10 cm diameter of Si NW thin film, (S5) pattering the Si NW thin film by PDMS mold, (S6) determination of effective channel length of 23 Si NW bridged FET; ESI 2: a real time movie displaying the process of the destruction of the thin film after covering Petri-dish with a lid; ESI 3: a real time movie displaying the process of the formation of a thin film of Si NWs. See DOI: 10.1039/c1jm12167g

A spontaneous assembly route to form a thin film of nanowires (NWs) was demonstrated and its feasibility was confirmed through the fabrication of a high-performance multi-Si NW field effect transistor (FET) using this route. Governed by the three mechanisms of spreading, trapping, and two-dimensional packing, the route was optimized for the concentration of Si NWs and the initial volume ratio of aqueous hydrochloride solution to isopropyl alcohol. The successfully formed Si NW thin-film was transferred on a flat polydimethylsiloxane (PDMS) mold and regulated using a repeatable conformal contact method with a new flat PDMS to prepare it for decal printing on an organic dielectric layer. Finally, after depositing the source and drain electrodes on the printed active layer, a high-performance 23-bridged Si NW FET exhibiting a μeffof 51.4 cm2V−1s−1, an on/off drain current ratio of 105, and a Vthof −2.7 V was obtained. [ABSTRACT FROM AUTHOR]