# Recombination current in a p-n junction

1. Dec 1, 2013

### VortexLattice

Hello all, I'm reading about rectification in a p-n junction. My book says there are two types of current for a p-n junction not in equilibrium: Generation current, and Recombination Current.

Generation current Seems simple enough, but I don't get something about Recombination current. They say that, if the potential across the depletion layer is $\Delta \phi$, the amount of holes that gets across the depletion layer (from the p-type to n-type side) through thermal motion will be proportional to $e^{-\beta e \Delta \phi}$, where beta is the normal thermal energy term.

Where do they get this equation?

Thanks!