(135f) High-Yield Self-Limiting Dielectrophoretic Assembly of Silicon Nanowires in Steady Flow

Single-crystal nanowire transistors and other nanowire-based devices can have application in LCD/OLED displays, flexible electronics, sensors, and photovoltaics if conventional top-down fabrication techniques can be integrated with high-precision bottom-up nanowire assembly.  In this work, dielectrophoretic assembly of nanowires onto surfaces is extended to make the process deterministic at each assembly site.  This is accomplished by the balancing of surface, hydrodynamic and confined field forces, which makes the self-assembly process controllable and self-limiting.  We present the mechanism of this of this self-limiting assembly process and elucidate the underlying physicochemical forces.  This process allows for extremely high yields of single nanowires assembled over large areas and with submicron alignment precision.  In addition, this approach represents a methodology to quantify nanowire assembly, and makes single nanowire assembly possible over an area limited only by the ability to reproduce process conditions uniformly.