What is pn junction diode explain in brief?
A p-n junction diode is a basic semiconductor device that controls the flow of electric current in a circuit. It has a positive (p) side and a negative (n) side created by adding impurities to each side of a silicon semiconductor. The symbol for a p-n junction diode is a triangle pointing to a line.
What is a pn junction diode Class 12?
Definition: A p-n junction is an interface or a boundary between two semiconductor material types, namely the p-type and the n-type, inside a semiconductor. The p-side or the positive side of the semiconductor has an excess of holes and the n-side or the negative side has an excess of electrons.
What is the main function of pn junction diode?
A diode (PN junction) in an electrical circuit allows current to flow more easily in one direction than another. Forward biasing means putting a voltage across a diode that allows current to flow easily, while reverse biasing means putting a voltage across a diode in the opposite direction.
How does current flow in pn junction diode?
In a forward-biased PN junction, once the barrier voltage is overcome, it conducts a current. The externally applied potential pushes majority carriers toward the junction where recombination takes place, allowing current flow.
Which is an example of pn junction diode?
A p-n junction diode is two-terminal or two-electrode semiconductor device, which allows the electric current in only one direction while blocks the electric current in opposite or reverse direction. The p-n junction diode is made from the semiconductor materials such as silicon, germanium, and gallium arsenide.
How can make pn junction diode?
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.
Why pn junction is called a diode?
A diode is called a diode because it has two distinct electrodes (i.e. terminals), called the anode and the cathode. A diode is electrically asymmetric because current can flow freely from the anode to the cathode, but not in the other direction.
How pn junction is formed?
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. A “built-in” potential Vbi is formed at the junction due to E.
What are the different types of pn junction?
Different types of PN-junction diodes
- Light Emitting Diode (LED) Very much used in a dancing light display of music systems and information boards on railway stations.
- Photodiode. A PN junction diode made of photosensitive semiconductor is called a photodiode.
- Solar Cell.
- Zener Diode.
How do holes move in pn junction?
When voltage is applied in the forward direction of the p-n junction. When holes and electrons meet at the interface (junction), the electrons jump into holes and both are eliminated. After those electrons are eliminated, more electrons flow into the n-layer, and electrons flow out from the p-layer, creating new holes.
How does current flow in PN junction diode?
What are the biasing conditions for a p-n junction diode?
There are three biasing conditions for p-n junction diode and this is based on the voltage applied: Zero bias: There is no external voltage applied to the p-n junction diode. Forward bias: The positive terminal of the voltage potential is connected to the p-type while the negative terminal is connected to the n-type.
How do you make a PN junction diode?
To make a p-n junction diode, a different impurity is added to each side of a silicon semiconductor to change how many extra holes or electrons are present. In a pure silicon semiconductor, there’s an equal number of holes to electrons. If there are more holes than electrons, then that side is the p-side.
What is a p-n diode?
Since the p-n junction demonstrates such a unipolar (rectifying) response to the applied voltage it is called a p-n diode and is denoted in circuit diagrams as a following symbol: The current voltage (IV) characteristic for the diode is rectifying and is very different from that for a resistor.
What are the current–voltage characteristics of a junction diode?
V-I Characteristics of PN Junction Diode In the current–voltage characteristics of junction diode, from the first quadrant in the figure current in the forward bias is incredibly low if the input voltage applied to the diode is lower than the threshold voltage (Vr). The threshold voltage is additionally referred to as cut-in voltage.