I've read about photo voltaic cells which converts the solar energy into electrical power. I find out that when they receive photons (light), the electrons of a photo voltaic cell are able to move freely and produce electrical current. I know that any material consists of electrons, protons, and neutrons. So I imagine that .. when electrons leave a photo voltaic cell, It should have less mass and it should start to erode or to be ionized and converted into another material. Am I right ? If no, how photo voltaic cell recover the loss of electrons ? I don't think photons of sun light replace the electrons !! because they just motivate electrons to move freely by giving them some energy. I also, thought the same Idea about piezoelectric material. when we give it a mechanical energy , it produces electrical current. does that mean it will erode ?

 

Look at it like an electric generator or even an in-line water pump. What goes out is returned. The generator, PV cell, or water pump just provide motive force. There s no net loss of electrons.

This reference is a little more detailed: http://org.ntnu.no/solarcells/pages/Chap.4.php

John

 

Don't think of the PV as a finite source of electrons. Think of it as a facilitator of electrons.

 

A PV cell generates an EMF to move the electrons from the positive to negative side of the cell in a continuous stream through a conductor connecting the two sides.
There is no net loss or gain of electrons.

 

It also takes 1837 electrons to equal the mass of one proton.

 

It also takes 1837 electrons to equal the mass of one proton.

But the charge is the same (but opposite).

A current of 1A is 1 Coulomb (of charge) per second. A coulomb is 6.241509×10^18 electrons.

Just thought you would like to know that!