Question

Solid State Electronic Devices (7th Edition) CHAPTER4, PROBLEM9P

I know that in electric field electrons have saturation velocity. And I wonder that does hole have saturation velocity. And why?

Answer 1

Saturation velocity is the maximum velocity of charge carrier in a semiconductor, attain in the presence of electric field. It happens with all kind of charge carrier whether it is electron or holes. In physics, the hole is nothing but a lack of an electron at a position where one could exist in an atom. If a electric field is applied, electron leave the atom and starts drifting towards positive potential. As the electron is moving, it left behind a hole and as it further move another hole is created. We can say as if hole is moving. When electron aquire a saturation velocity so does the hole as a consequence. So electron and hole both have saturation velocity in high electric field.