built-in-potential

A P + -N junction has a built-in potential of 0.8 V. The depletion layer width at a reverse bias of 1.2V is 2 µm. For a reverse bias of 7.2 V, the depletion layer width will be:

The diffusion potential across a P-N junction

The built-in potential (Diffusion Potential) in a p-n junction