Semiconductor nanowires (NW) represent an ideal system for investigating low dimensional physics and are expected to play an important role as both interconnects and functional device elements in nanoscale electronic and optoelectronic devices. In this talk, I will present a series of key advances towards integrated nano-systems from the bottom-up approach using semiconductor NW building blocks.
I will first introduce a general approach to controlled synthesis of a broad range of semiconductor NWs via a metal cluster-catalyzed vapor-liquid-solid (VLS) growth mechanism, followed by discussions of the electronic and optical properties of these semiconductor nanowires. Subsequently, I will demonstrate the development of hierarchical assembly methods used to organize NW building blocks into functional devices and complex architectures. In particular, electric fields and microfluidic flows have both been explored for the assembly of NWs with controlled spatial location and directionality. Next, I discuss a variety of conceptually new nanoscale electronic and photonic devices, and device integrations enabled by high quality NWs and flexible assembly methods. I will give a few examples of novel electronic devices such as crossed nanowire p-n diode, crossed nanowire field-effect transistor (FET) and integrated logic circuits, as well as optoelectronics devices including light emitting diodes (LED), multi-color LED arrays, and integrated LED-FET smart pixels. Lastly, exploration of the potential to incorporate nanowire optical functions into conventional silicon microelectronic circuits and the potential to fabricate nanoscale laser diodes will be discussed.