NANOWIRE POWERS pH METER

NANOSTRUCTURES and nanostructured materials are of key interest to some solar cell designers, both to provide next-generation materials for commercial solar panels and to power nanoelectronic devices. In a leap forward for nanoenabled power technology, researchers at Harvard University have constructed a layered, coaxial silicon nanowire that can directly absorb light and turn it into electricity, as well as power a nanoelectronic device. A standard approach to manufacturing amorphous silicon solar cells involves the assembly of “p-i-n” diodes, in which intrinsic, or undoped, silicon is layered between p- and n-type materials, which accommodate positive and negative charge carriers, respectively. The layering sets up an electric field between the p- and n-layers, with the intrinsic component serving as a resistor. Light generates electrons and holes in the intrinsic region; the holes and electrons then separate to the p- and n-layers. The Harvard researchers, led by chemistry professor Charles M. Lieber, ...