Theory
1.) The light energy will be absorbed by semi-conducting materials like silicon when photons in sunlight hit the solar panel.
2.) Negative-charged electrons are knocked loose from atoms and are able to flow through the material to produce electricity while the positive-charged holes flow in opposite direction.
When a photon hits a piece of silicon, the photon can pass straight through the silicon — this (generally) happens for lower energy photons, reflect off the surface, and it could also be absorbed by the silicon, if the photon energy is higher than the silicon band gap value. This generates an electron-hole pair and sometimes heat, depending on the band structure. Hence current electricity will be created.
When a photon hits a piece of silicon, the photon can pass straight through the silicon — this (generally) happens for lower energy photons, reflect off the surface, and it could also be absorbed by the silicon, if the photon energy is higher than the silicon band gap value. This generates an electron-hole pair and sometimes heat, depending on the band structure. Hence current electricity will be created.
3.) The two main modes for charge carrier separation in a solar cell are namely drift of carriers, which is driven by an electrostatic field established across the device, and the diffusion of carriers from zones of high carrier concentration to zones of low carrier concentration.
In the p-n junction solar cells, the dominant mode of charge carrier separation is by drift. However, in non-p-n-junction solar cells (typical of the third generation of solar cell research such as dye and polymer thin-film solar cells), a general electrostatic field has been confirmed to be absent, and the dominant mode of separation is via charge carrier diffusion.
In the p-n junction solar cells, the dominant mode of charge carrier separation is by drift. However, in non-p-n-junction solar cells (typical of the third generation of solar cell research such as dye and polymer thin-film solar cells), a general electrostatic field has been confirmed to be absent, and the dominant mode of separation is via charge carrier diffusion.
Wikipedia. (2007). Solar Cell. Wikipedia: The free encyclopedia. [on-line]
URL: http://en.wikipedia.org/wiki/Solar_cell (01/07/08)
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