Difference Between P N Junction Diode and Zener Diode (With Table)

Our world changed with the discovery of electricity, we get our word done easily, and that gave us more time to think and invent new things. Many electrical and electronic devices around us come into existence in a few periods after electricity. Similarly, diodes are small but very important part of every piece of electronic equipment that most people don’t aware of. There are many types of diodes, like PN junction Diode and Zener Diode.

P N Junction Diode vs Zener Diode

The difference between the PN junction diode and Zener diode is that the PN junction diode works as a simple diode as it allows the flow of electron in one direction only and can get damaged when current is passed through opposite direction, whereas the Zener diode can be characterized as a unique diode that allows the flow of current in both directions.

PN junction diode is like a simple diode that allows the flow of electron only in one direction. It is generally made using semiconductors like silicon or germanium. In this diode, layer P of the semiconductor is joined to the N layer of the semiconductor using the alloying method. It is used as rectifiers, voltage multipliers, etc.

In contrast, the Zener diode is a diode that allows the flow of current in both forward and reverses directions. It is made using semiconductors like silicon. It has highly doped junctions. The breakdown voltage for Zener diodes is comparatively lower, and it is known as Zener voltage. It is generally used as voltage stabilizers.

Comparison Table Between P N Junction Diode and Zener Diode

Parameters of ComparisonP N Junction DiodeZener Diode
Definition It is a type of diode that allows the flow of current in one direction only.It is a type of diode that allows the flow of current in both directions.
Doping LevelIt is not highly doped as it allows current only in forward breakdown condition.It is a highly doped diode, as it is also used in reverse bias conditions.
Breakdown Voltage The breakdown voltage is comparatively higher.The breakdown voltage is comparatively lower.
Ohms LawIt obeys Ohms Law.It does not obey Ohms Law.
Application It is used as voltage rectifiers.It is used as voltage stabilizers.

What is P N Junction Diode?

PN junction diode is a type of diode that allows the flow of current in one direction only. It does not resist the current while the current is going in the forward direction, but when the current comes backwards, it increases its resistance that stops the current from going in the opposite direction.

It is made of semiconductors like silicon and germanium. The layer P of semiconductor is put on N layer semiconductor to make a PN junction diode. In the first layer of semiconductor, holes are the main carrier, whereas the second layer of semiconductor electrons is the main carrier.

Both the layer is not just connected using simple coupling method, but it uses very much complicated technological process. As there are more electrons in the N layer, hence after connection, there is a diffusion of holes and electrons. There is a movement of electrons from the N layer to P, and holes move from layer P to N to make equal concentration on both sides.

The PN junction diode is represented using a diagram. In that diagram, there is an arrowhead known as anode and a bar on it known as cathode. All these things are represented on a straight line. It has various uses and applications in electronic equipment. It is used as rectifiers, voltage multipliers, waveshapers, etc.

What is Zener Diode?

Zener diode is listed as a special type of diode that allows the flow of electron in both directions. It has a highly doped p and n junction. It allows the current to flow backwards when the voltage crosses a certain value. This certain value is known as breakdown voltage or Zener voltage.

The Zener effect was discovered in 1934 by American physicist Clarence Zener when he was studying the voltage breakdown in insulator properties. Hence this Zener effect was named after him, and Zener diode works on the Zener effect. It tells about the breakdown voltage of the diode, which is comparatively low in this diode and known as Zener voltage.

It is generally made of silicon, and the concentration of ions is more in the material of the diode. Whenever the current is passed from this diode, the depletion layer between the junction reduces, and due to this, the electric field concentration increases. An increase in voltage leads to ions of electrons going towards the depletion region to make it conductive.

It has its application in various electronic equipment, and it is an essential part of electrical circuits. It is used at places where voltages vary as it can provide a constant voltage to the load. Hence it is used surge protectors and voltage stabilizers.

Main Differences Between P N Junction Diode and Zener Diode

  1. The main difference between the PN junction diode and the Zener diode is that the PN junction diode allows the flow of electron in one direction only, whereas the Zener diode allows the flow of electron in both directions.
  2. The voltage of the PN junction diode at which it starts working is comparatively higher, and the voltage of the Zener diode at which it starts working is lower, and it is known as Zener voltage.
  3. The PN junction diode is not highly doped. On the other hand, the Zener diode has highly doped junctions.
  4. On applying a large reverse bias voltage, the PN junction diode has chances of getting damaged, but the Zener diode is specialized for this case.
  5. PN junction diode is used as voltage rectifiers, switchers, waveshapers, etc., whereas Zener diode is used as voltage stabilizers.

Conclusion

Diodes are a small but important part of electronic systems. It was developed in the 1900s as a vacuum tube. Since then, it is developed into what we are using now. There are different types of diodes use for various purposes. PN junction diode and Zener diode is two completely different diodes.

PN junction diode is a normal diode that allows working in forwarding bias conditions only. It is made up of semiconductors like silicon and germanium. It is used as voltage rectifiers, switchers, etc. In contrast, the Zener diode is a special diode that is used reverse bias conditions. It is used as voltage stabilizers.

References

  1. https://onlinelibrary.wiley.com/doi/abs/10.1002/adma.200306185
  2. https://www.cambridge.org/core/journals/mrs-online-proceedings-library-archive/article/study-of-zener-diodes-by-semdvc/88F7CB35265416463D397AD438FF1816
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