Improving Solar Cells

How do we catch photons, and lots of them? That's one of the big problems to solve when building a solar cell.

Photovoltaic cells absorbs the energy of light, creating an electric current in a solar cell. These are not cells like the cells in our bodies. They are essentially tiny power stations made of semiconductor material like silicone. When a photon hits the silicone in a photovoltaic cell, the energy of the photon knocks loose electrons in the silicone and allows them to become part of an electric current, or in other words, we get electricity.

And guess what's most expensive in building a solar cell? Yup. The photovoltaic cell. It's a cruel, cruel world.

One way to make solar cells more affordable, is to reduce the amount of photovoltaic material needed, but how could we do that? How could we concentrate the light onto a photovoltaic cell?

None other than lenses and curved mirrors do the job.

By using conversing lenses or mirrors, we can collect light over the relatively large surface of the lens or mirror, and then focus all of that light on a very small surface, the photovoltaic material.

There we have it. Using converging lenses and mirrors improves efficiency while lowering the cost of solar cells. Optics for the win!