Contents
How does a PN junction works?
When a p-n junction is formed, some of the free electrons in the n-region diffuse across the junction and combine with holes to form negative ions. In so doing they leave behind positive ions at the donor impurity sites. Show more detail of depletion region.
How diode is formed?
A diode is formed by joining two equivalently doped P-Type and N-Type semiconductor. At the point of contact of the P-Type and N-Type regions, the holes in the P-Type attract electrons in the N-Type material. Hence the electron diffuses and occupies the holes in the P-Type material.
What is the use of PN junction?
Applications of PN Junction Diode p-n junction diode can be used as a photodiode as the diode is sensitive to the light when the configuration of the diode is reverse-biased. It can be used as a solar cell. When the diode is forward-biased, it can be used in LED lighting applications.
How are p-n junctions formed in semiconductors?
P-n junctions are formed by joining n-type and p-type semiconductor materials, as shown below. Since the n-type region has a high electron concentration and the p-type a high hole concentration, electrons diffuse from the n-type side to the p-type side. Similarly, holes flow by diffusion from the p-type side to the n-type side.
How is the electric field formed in a PN junction?
In a PN-junction, when the electrons and holes move to the other side of the junction, they leave behind exposed charges on dopant atom sites, which are fixed in the crystal lattice and are unable to move. The electric field Ê forms between the positive ions cores in the n-type material and negative ion cores in the p-type material.
What happens in the depletion region of a PN junction?
Movement of electrons to the p-type side exposes positive ion cores in the n-type side while movement of holes to the n-type side exposes negative ion cores in the p-type side, resulting in an electron field at the junction and forming the depletion region. A voltage results from the electric field formed at the junction.
How are electrons diffused in a PN junction?
Joining n-type material with p-type material causes excess electrons in the n-type material to diffuse to the p-type side and excess holes from the p-type material to diffuse to the n-type side.