A new discovery coming the Northwestern University could make solar cells embeddable in clothes and various fabrics. It involves changing tin, an important element of solar cells, with carbon nanotubes, considered more flexible and efficient.
For a solar cell to be transparent and still function, it has to have several layers, of which a transparent conductor one allows some of the light to pass into the cell to get transformed into electricity and some to pass through the cell, to provide the transparency. Tin is the manufacturers’ number one choice when it comes to transparent solar cells.
Tin is used in its oxidized form, as indium tin oxide, but it has two drawbacks. One is that indium tin oxide is extremely brittle, which makes for the all-known easily-breaking solar cells. The other is its price, that tends to raise with the consumption of indium and the demand for more solar power around the world.
“If solar technology really becomes widespread, as everyone hopes it will, we will likely have a crisis in the supply of indium. There’s a great desire to identify materials Ã¢â‚¬â€œ especially earth-abundant elements like carbon Ã¢â‚¬â€œ that can take indium’s place in solar technology,” said Mark C. Hersam, professor of materials science and engineering and professor of chemistry and the team’s leader.
By replacing indium tin oxide with single-walled carbon nanotubes, the researchers found that the resulting metallic nanotubes were 50 times more efficient than semiconducting ones, when used as transparent conductors in organic solar cells.
“With this mechanically flexible technology, it’s much easier to imagine integrating solar technology into everyday life, rather than carrying around a large, inflexible solar cell,” Hersam said.