A simple and rapid formation of wet chemical etched silicon nanowire films at the air–water interface

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 μeff of 51.4 cm2 V−1s−1, an on/off drain current ratio of 105, and a Vth of −2.7 V was obtained.