How is solar energy converted into electricity?

Answer

Solar cells are made from materials called semiconductors. Silicon is the best example of this: it is also the material from which the microprocessor in your computer is made. There are also other examples such as Germanium or Gallium-Arsenide (GaAs), but they can also be special forms of polymers, for example.

Semiconductors have the property that if light of a certain wavelength (wavelength can be interpreted as the color of the light) impinges on the material, an “electron-hole pair” is formed. This “electron-hole pair” is really nothing more than a pair of particles consisting of a negatively and positively charged one.

Now one can apply impurities in semiconductors (eg As or B in Silicon) and thus make a diode. Such a diode has the property that an internal electric field is built up in it through which it can separate the couple of the negative and positive charges from each other and send the negative charge to one pole of the diode and the positive charge to the other. . If you now apply electrodes to the two poles of the diode, you can collect the charges and thus create a voltage and current.