The Depletion Region

1. The electrons which diffuse across the region rapidly recombine with recombine with some majority holes exist in the p region and therefore disappear from the scene.
2. This effect also in disappearance of some majority holes, causing some bound negative charge to be uncovered (for example no longer neutralized by holes). Therefore in the p material near to the junction that is depleted of free electrons.
3. This p region will have uncovered bound negative charge, as showed in the diagram.
4. From the above this follows that a carrier depletion region will present on both sides of the junction.
5. Having n side of this region positively charged & p side negatively charged. This carrier depletion region or merely, depletion region is also known as the SPACE CHARGE REGION.