- Difference in concentration of charge carrier in the two sections of P-N junction.
- The electrons from N-region diffuse through the junction into p-region and the hole from p region diffuse into N-region.
- Neutrality of both N and P-type semiconductors is disturbed, a layer of negative charged ions appear near the junction in the p-crystal and layer of positive ions appears near the junction in N-crystal.
- The solid circles on the right of the junction represent the available electrons from the n-type dopant. Near the junction, electrons diffuse across to combine with holes, creating a “depletion region”.
- Depletion region is a region near the p-n junction where flow of charge carriers (free electrons and holes) is reduced over a given period and finally results in zero charge carriers.