How does a photovoltaic cell work?
Photovoltaics: a cutting
PV cells work according to a basic physical phenomenon called 'photoelectric effect'.
01. when the energy of photons hitting a semiconductor plate is high enough (light has the right colour), it can be absorbed by electrons on the surface of the semiconductor plate exposed to such radiation.
02. The absorption of additional energy enables the (negatively charged) electrons to free themselves from their atoms. The electrons become mobile, and the space which is left behind is filled by another electron from a deeper part of the semiconductor.
03. As a consequence, one side of the wafer has a higher concentration of electrons than the other, which creates voltage between the two sides. Joining the two sides with an electrical wire enables the electrons to flow to the other side of the wafer – which is electrical current.
The photoelectric effect: from photons to electrical current