| MadSci Network: Engineering |
Did you know that Albert Einstein won a Nobel Prize in 1921 for explaining the photovoltaic effect?
The photovoltaic effect is based on quantum physics. Each electron in an atom has a certain energy, no more and no less. Each photon of light or any other electromagnetic radiation has a specific amount of energy. Only when the energy of the photon is just right can an electron be dislodged from an atom and move across a junction to create an electrical current. It turns out for the silicon based photovoltaic cells we use today the photons that can create an electrical current correspond to visible light.
Other materials may be used in the future that can take advantage of the other parts of the electromagnetic spectrum. For the moment, though, the necessary materials do not exist in the ultrarefined states needed for photovoltaic cells.
For more information on the photovoltaic effect and photovoltaic cells/systems, you can go to the Utility PhotoVoltaic Group's Web page What is PV?. It gives some good history, an explanation of the photovoltaic process and what the current state of the art is. The Photovoltaic and Space Environment Effects Branch at NASA's Glenn Research Center is also heavily involved in photovoltaic cell development.
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