Transparent and Colored Solar Cells Created
Many people already dream of a day when traditional glass windows can be replaced with transparent solar cells, but what about a stained glass window? Thanks to researchers at the University of Michigan, that future looks to be a possibility as they have created transparent, colored solar cells.
The traditional solar cells we can find on some buildings are made of silicon and are a simple black in color. These new cells however are comprised of a layer of amorphous silicon and two semi-transparent electrodes, of which one is an organic material. This combination of organic and inorganic allows the cell to be ten times thinner than traditional amorphous silicon cells, as it replaces a thick doped layer. What gives the cell their colors are changes in the thickness of the amorphous silicon, with 6 nm thick corresponding to blue and 31 nm corresponding to red. Other color solar cells have relied on dyes and microstructures, but these can blur images placed behind them.
As can be expected, giving the solar cells a color has the tradeoff of reducing their efficiency, with one of the constructed cells only achieving 2% efficiency. With further work and new materials though, it may be possible to bring that number up, making colorful, solar-cell windows a useful endeavor.
Source: University of Michigan