The layer where the flow of charges slows down is known as the Depletion Region. The region serves as a barrier to prevent electrons from moving from the semiconductor diode’s n-side to its p-side.
The junction between the p-type and n-type materials behaves differently from each side of the material alone when they are kept in contact with one another. At the junction, electrons and holes are in close proximity to one another. Coulomb’s law states that a force exists between the positive holes and the negative electrons. A few n-type electrons diffuse through the p-n junction during its formation, combining with the holes on the p-side to generate negative ions while leaving behind positive ions on the n-side. As a result, the depletion layer is created, acting as a barrier to prevent additional electron transport from the n area to the p region.
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