June 1, 2009

Strained nanowires promise cheaper solar cells

Put nanowires under strain and you've got a way to lower the cost of silicon solar cells.

A computer model shows that a silicon nanowire that has a section under strain, meaning its silicon atoms are forced slightly out of their normal alignment, can channel electrons into a circuit just like layers of different semiconductor materials do.

When photons produce electrons in solar cells, the electrons and the holes they leave behind are separated and fed into opposite ends of an electric circuit. This is usually accomplished in high-performance crystalline silicon solar cells by two layers of silicon. One layer is doped, or infused with atoms of another material, to be electrically positive. The other layer is doped to be negative.

Strained silicon nanowires separate electrons and holes simply by the wires' small size and the strained crystal structure. If the silicon nanowires can be readily mass-produced, they could lower the cost of silicon solar cells because they don't need doping and they can be made from lower-grade silicon.

Research paper:
Charge Separation via Strain in Silicon Nanowires
Nano Letters, published online May 22, 2009

Researchers' contact:
The Grossman Group

Back to ERN June 1, 2009



News  | Blog

E-mail headlines

Energy-related books and products from

Home   Archive   Eric on Energy   Researchers   Links   About   Contact
© Copyright Technology Research News 2008-2010. All rights reserved.