Ultra Thin Solar Cells – With “Doubled” Power Efficiency

We’ve dealt with solar cells a few times already in previous articles… There is a common limitation in conventional, thicker solar cells. When they absorb a high-energy photon they produce a hot electron that quickly loses much of its energy as heat before it can pass through the cell and be used to generate electricity. So in these older solar cells only low-energy, ‘cooler’ electrons that have longer wavelengths can pass through.

There is now a solution however…

And that comes in the form of an ultra thin solar cell that is so thin, even the hot electrons with shorter wavelengths can pass through!

And the result?

A potential for doubling the solar cell efficiency!

Conventional solar cells…

Can convert at most about 35% of sunlight energy into electricity, and the rest is wasted as heat. By absorbing the hot electrons, solar cells could achieve efficiencies of up to 67% according to an article in MIT’s technology review.

Image of an ultra-thin solar cell (Credit: Michael Naughton)

So what’s the take-home?

Solar cells that can absorb both hot and cool electrons can theoretically double their power efficiency and by doubling the efficiency, the cost of solar power could also be cut in half!