How do solar pannels work?

[herpguy]

I was just wondering, how do solar pannels work? Thanks.

 

-Herpguy

[Cap'n Refsmmat]

http://science.howstuffworks.com/solar-cell.htm

[m4rc]

Normally in semiconductors, the valence band is full and the conduction band is empty. Despite the name the electrons in both the valence band and conduction bands are mobile and contribute to electrical currents. By absorbing the energy from light, a electron from the valence band can be promoted to the conduction band. When the electron gets promoted to the conduction band, a electron vacancy (usually refered to as a hole) is produced in the valence band. Impurities in solar cells are distributed in the solar cell (more on one side then the other) so that the electrons require less energy to be on one side. As a result, less energy is required for the electron vacancies(holes) to be on the other side. Therefore there will be an excess of negative chages on one side and this junction can be used like a battery. This excess of charges can only be maintained as long as light continued to promote electrons into the conduction band.

[herpguy]

Thanks.