(430b) Semiconductor Nanowire Fabric

Semiconductors, like silicon (Si) and germanium (Ge) for example, are brittle and relatively fragile materials. In nanowire form, however, they are mechanically flexible and strong. For example, we have measured the bending strength of individual Ge nanowires using nanoprobe techniques and found it to be equal to the ultimate strength of a perfect Ge crystal (~20 GPa). The corresponding strength-to-weight ratio is more than an order of magnitude higher than steel and similar to Kevlar. Since we have developed synthetic methods to produce significant amounts of semiconductor nanowires using solvent-based routes and can obtain gram-scale quantities, we have been exploring new applications like nanowire-based textiles and nanowire-polymer composites that might exploit their unique combination of mechanical and semiconductor properties. We have demonstrated that nanowires can be embedded in a polymer matrix or compacted together as a free-standing non-woven fabric, and have used them to create a prototype solar cell. This presentation will present this work and discuss some of the key challenges facing large-scale nanowire synthesis and their use in these kinds of applications.