Sunday, March 9, 2008

Rainbow Solar Cells?

Notre Dame (TGW) – Researchers at Notre Dame have created solar cells made of different sized quantum dots, each capturing a specific wavelength of light.

By arranging these dots in an ordered pattern, the researchers hope to create “rainbow” solar cells which efficiently harvest a large part of the visible spectrum of light.

By varying the size of the tiny semiconductor quantum dots, the researchers can tune the solar cells to absorb light of certain wavelengths. Smaller quantum dots absorb shorter wavelengths of light, while larger quantum dots absorb longer wavelengths.

By combining different sized dots in a solar cell, the researchers can create a cell that absorbs more light and therefore is more efficient.

Two main challenges remain: the first is organizing the nano dots, and the second is the quantum dots should generate multiple charge carriers to be captured to generate photocurrent.

The dots also show promise in developing solar windows, in which the color of the window could be changed while still creating energy.

Via :: Physorg