# How is this equation derived?

1. ### Turion

148
Equation in pink:

I was absent so I was going through the slides and I saw that equation. There isn't a derivation shown. Do you guys have any ideas?

Last edited: Sep 29, 2013
2. ### Turion

148
This is for solid state physics.

n0 represents the number of electrons in a semiconductor. p0 represents the number of holes in a semi conductor.

NA represents the number of positive (acceptor) ions. ND represents the number of negative (donor) ions.

ni=pi=n0=p0 in an instrinsic semiconductor.