# Electron hole theory in Semiconductors

 P: 4 Hi guys. Could someone please explain to me this electron hole theory that people use to describe the behavior of electrons inside semiconductors? How do these holes move, in and out of a potential difference? Thanks guys.
 P: 324 The holes are just the abscence of a electron in a energy band. But its easier to describe the abscence of a electron as a single moving positive charge than it is to describe the motion of all the other electrons in the band. Think of it like this. In a band you have N electrons. Remove one of those electrons(by for instance p-doping) and you have N-1 electrons left. Now you can either choose to describe this with the behavior of those N-1 electrons. Or you can choose to describe it as if there is one single hole moving around in the band. So mathematicly the holes behave just like a positivly charged electron. But the holes themself never move in or out of potential differences because the holes are just a mathematical trick. What moves in and out of those potential differences are the N-1 electrons. I hope this explanation makes sense and answered your question :)
Emeritus