We’ve written about nanotubes quite a few times now. They seem to be working miracles on a minuscule scale. Now, they’re at the base of a new energy efficiency initiative in the U.S. that features solar cells that work all day long.
The cell featured by the scientists, working at the Georgia Tech Research Institute, has hundreds of thousands of little towers that can capture light and make it work even when all around is not bright sunlight. The finished towers are 100 micrometers tall, 40 micrometers wide, and 10 micrometers apart. Working the magic on top of layers of silicon wafers and patterned iron are those versatile carbon nanotubes, which are coated with semiconductors featuring cadmium telluride and cadmium sulfide.
The cell is counterintuitive in that it produces its highest rate of efficiency when light comes in at a 45-degree angle, which would be in the afternoon, when the sun is nowhere near its highest level in the sky. You would think that having the sun directly overhead would produce the most energy, but that isn’t the case with this solar cell.
These little tower-cells aren’t ready for prime time yet, but they might be soon.