Cheap, Efficient and High Quality Solar Cells from Caltech

What is a solar cell? A device that can convert the energy of incident sun light into electricity. Much of the industry is now focusing on the most efficient solar cells, in terms of both function and cost. A group of scientists from the California Institute of Technology (Caltech) has developed a new type of solar cell that demonstrates near-perfect efficiency with regard to both absorption of sunlight and conversion of photons into electrons.

Why is this special?

This particular solar cell can do all this, by using only a tiny amount of the expensive semiconductor material used in conventional solar cells!

So just how efficient is this device?

Researchers claim that these solar cells have surpassed the conventional light-trapping limit for absorbing materials for the first time ever! The light-trapping limit of a material is basically another way of referring to how much light the material can absorb. These new solar cells can absorb up to 96 % of incident sunlight at a single wavelength and 85 % of total collectible sunlight!

How is this possible?

These solar cells were created using arrays of long, thin silicon wires which were embedded in a polymer substrate. These silicone wire arrays are capable of converting between 90 and 100 % of the photons they absorb into electrons! That’s near-perfect absorption and near-maximum conversion.

The result? A high quality solar cell!

The secret for this efficiency is of course the silicon wire arrays. Each silicon wire is on its own, a high-efficiency, high-quality solar cell. So when they are brought together in an array they interact to further increase the cell’s efficiency. In terms of length each wire is between 30 and 100 microns with a diameter of only 1 micron. But here’s where this innovation differs from a conventional solar cell… in terms of area only a tiny 2 % of it is silicon, the rest is polymer!

As some of you might already know silicon is the expensive material in a conventional solar cell. So this new type of cell uses only 1/50^th of the expensive semiconductor material! So in addition to the high quality and the efficiency it is much cheaper as well!

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via: EurekAlert!