Semiconductor Diode

The Topic of Semiconductor Diode 

A diode is formed from semiconductor materials like silicon, germanium, and gallium arsenide. A diode is an electronic device that conducts electricity in only one direction. It has two terminals in total. A diode blocks the electricity that flows in the opposite direction. If the diode undergoes forward bias, the current flows through the diode. Therefore, if it is in the reverse bias, the current will not flow through the diode. 

A junction diode is where the p-type and n-type diodes are joined together. We also see that the holes carry the majority charge in p-type semiconductors, whereas the electrons are the majority charge carriers in n-type semiconductors. 

Now, let us study in-depth the p-n junction under forwarding bias. 

P-N Junction Under Forward Bias 

• The p-n junction under forwarding bias has the p-side connected to the positive terminal, whereas the n-side is connected to the negative terminal of any battery. The whole arrangement is reversed when the p-n junction is under reverse bias. The p-type is connected to the negative terminal, whereas the n-type is connected to the positive terminal.
• The positive terminal of the diode is the source for holes that carry electric charge in them. This is also known as the anode terminal. It helps in the supply of holes that carry charge in them. 
• If the semiconductor diode is forward biassed, the electrical current can flow. Under the forward-biassed conditions, the p-type unit is connected to the battery’s positive terminal. In contrast, the n-type unit is connected to the battery’s negative terminal.
• The p-type or the p-aspect of the semiconductor emits holes in the battery’s positive terminal. However, these can mix with the electrons present in the n-type. This can result in a decrease in the depletion layer and barrier potential. Henceforth, it decreases the resistance of the diode. 
• When the p-n junction diode is under forwarding bias, we notice that the p-type is connected to positive, whereas the n-type is towards the negative. This makes the anode terminal positive and the cathode terminal to be negative.
• The semiconductor diode is formed from semiconductor materials like silicon, germanium, and gallium arsenide. The semiconductor diodes made up of silicon semiconductors work at higher temperatures when put next to the semiconductor diodes made up of germanium semiconductors.
• The p-n junction under forwarding bias often has the negative side or n-type electrons jump to the positive side or p-side and mix with them. This causes the majority of charge carriers to mix with the holes. 

PN Junction Under Reverse Bias 

• The semiconductor diode under reverse bias has the p-type or p-side of the semiconductor connected to the negative terminal of the battery, whereas the n-type or n-side is connected to the positive terminal. This is the total opposite of the semiconductor under forwarding bias.
• If the semiconductor diode is forward biassed, the electrical current can flow. Under forward bias conditions, the semiconductor unit is connected to the p-type terminal of the battery, whereas the n-type unit is connected to the negative terminal of the battery.
• For a p-n junction under reverse bias, an external voltage is applied over the whole arrangement. However, the direction of the external voltage applied across the arrangement is similar to that of the external potential of the arrangement. This increases resistance. Thus, the transfer of the charge carriers from one side to the other is far less than before. 

Characteristics of P-N Junction Diode 

There are many basic characteristics of the P-N junction diode. They are mentioned below: 

• When the p-n junction is in forwarding bias, the p-type side of the terminal is connected to the positive terminal of the battery. On the other hand, the negative terminal is connected to the n-type side of the terminal. 
• When no voltage is applied across the terminal, no current flow occurs. This condition is known as the zero bias of the p-n junction.
• When the p-n junction is in reverse bias, the n-type side is connected to the positive terminal. Likewise, the p-type side of the terminal is connected to the negative terminal of the battery. 

• When the diode is in forwarding bias, the width of the p-n junction increases. 

• When the diode is in reverse bias, the width of the p-n junction diode decreases. 

Conclusion

This module taught us about the semiconductor diode. Further, we also discussed the p-n junction under forwarding bias and the p-n junction under reverse bias. 

The p-n junction under forwarding bias has the p-side connected to the positive terminal, whereas the n-side is connected to the negative terminal of any battery. The whole arrangement is reversed when the pn junction is under reverse bias. 

The p-type is connected to the negative terminal, whereas the n-type is connected to the positive terminal. The semiconductor diode under reverse bias has the p-type or p-side of the semiconductor connected to the negative terminal of the battery, whereas the n-type or n-side is connected to the positive terminal.