Solar Energy: The Physics And Engineering Of Ph... -

The foundation of solar energy is the , first observed in 1839 by Edmond Becquerel. To understand how it works, we have to look at the subatomic level of semiconductors, usually silicon.

When a photon (a particle of light) hits the solar cell with energy equal to or greater than the band gap, it knocks an electron loose. This creates an electron-hole pair . Solar Energy: The Physics and Engineering of Ph...

In a semiconductor, electrons exist in a "valence band" where they are bound to atoms. Above this is the "conduction band." The energy difference between these two is the band gap. The foundation of solar energy is the ,