The photovoltaic phenomenon described as the polarization of electrical charges occurring in certain materials when exposed to bright light. This occurs in the natural elements in the group of semiconductors and semiconductor devices to artificial. The polarization of electrical charges translates as creating potential difference generated between the poles, ie a rudimentary electric generator.
Colorful, we could liken the photovoltaic generator as a non-return valve electrons, whereby the electrons can pass only to one direction. So when I happened to hit a photon on an electron of the material, then the broadcast of its energy, causing it to "hurl" from the rest position. If now the direction we will take the "Flying" electron coincides with the direction of electron valve then it will shift in relation to its original position and trapped there after the valve prevents the return to the starting position. Accordingly, we find that in a "side" of the material (hand entrapment) will have an excess electron and the other side (side eksfendonismou) will have an electron deficit, which implies a difference of electrical potential.
More intensity (as looking at material which has the status of non-return valve) depends on three main factors: (1) the availability of electrons "can fly away (electrical properties of the material), (2) the likelihood of conflict photon-electron (statistical probability) and (3) the ability of the conflict to give the appropriate electron velocity and direction to switch on the side traps (also statistical probability). From these dependencies, it is understood that a small percentage of the light irradiation takes place in the photovoltaic effect.