Why silicon is not used in constructing tunnel diode?
Construction of Tunnel Diode The p-type semiconductor acts as an anode, and the n-type semiconductor material acts as a cathode. Hence silicon is not used for fabricating the tunnel diode. The doping density of the tunnel diode is 1000 times higher than that of the ordinary diode.
Why tunnel diode is heavily doped?
The p-type and n-type semiconductor is heavily doped in a tunnel diode due to a greater number of impurities. Heavy doping results in a narrow depletion region. When compared to a normal p-n junction diode, tunnel diode has a narrow depletion width.
What happens to a tunnel diode when the reverse bias effect goes beyond the valley point?
Explanation: After the valley point is crossed, the tunnel diode obtains positive slope resistance. That is similar to the characteristics of a normal diode. So it behaves like a normal diode after beyond valley point.
Is tunnel diode heavily doped?
A Tunnel diode is a heavily doped p-n junction diode in which the electric current decreases as the voltage increases. In tunnel diode, electric current is caused by “Tunneling”. The tunnel diode is used as a very fast switching device in computers.
What is Tunneling effect in tunnel diode?
As the width of the depletion layer reduces, charge carriers can easily cross the junction. Charge carriers do not need any form of kinetic energy to move across the junction. Instead, carriers punch through the junction. This effect is called Tunneling and hence the diode is called Tunnel Diode.
What is negative resistance of tunnel diode?
Tunnel diode theory basics The key to understanding tunnel diode theory is the characteristic curve in which there is a negative slope – this indicates an area of negative resistance. An area of negative resistance means that if the voltage is increased, the current actually falls – the opposite to Ohms Law.
Which is the highest doped diode?
Zener diode is a special type of diode that is designed to work in reverse condition. Under forward bias condition, the diode acts as a normal diode. The Zener diode, however, is heavily doped, as a result, they have a thin depletion region.
What are the disadvantages of tunnel diode?
Disadvantages of tunnel diode:
- The voltage range, which can be operated properly in 1 volt or below.
- Being two terminal device, it provides no isolation between output and input circuit.
- The low output voltage swing.
- Tunnel diode cannot be fabricated in a large number.
What are the advantages of tunnel diodes?
Advantages of Tunnel Diode
- Low cost.
- Low noise.
- Ease of operation.
- High speed.
- Low power.
- Insensitive to nuclear radiations.