What is the physics behind solar cells?
Question:
Answer:
Solar cells work on the principle of the photoelectric effect. If you are not familiar with it, the photoelectric effect explains why when light shines on a metal plate, a current is created. It is because photons in the light displace electrons in the metal. When the electrons are displaced their movement creates a current. It is this effect that allows solar cells to generate electricity:)
This can explain the process much better than I ever could.
First let us look at a solid state diode. A silicon chip
(valence 4) is doped with boron and arsenic(valence 3 and 5)this creates a hole in the crystal lattice on one side and an extra electron in the crystal lattice on the other side when a charge is applied to the device + on the hole side and - on the electron side current flows, however a "junction voltage" of .7 volts is present. If this voltage is reversed very little current will flow. a solar cell is constructed much the same way, and photons of light knock the electron across the barrier between the doped sides and they cannot return across the barrier so a potential is developed. if a circuit is connected across the device, current will flow through the circuit until the electrons have returned to the electron side of the device.
If you are not electronically inclined it is as if you jumped off a wall that you could not climb back up, however if there was a path you could use you could climb back up and jump off the wall again.
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