Pn junction, diode and energy level of conduction band during forward biasing

In summary, the energy levels in a diode are higher on the p-side and lower on the n-side, with the Fermi energy line being the same for both. When the diode is forward biased, the conduction band on the p-side decreases while the conduction band on the n-side increases. This is necessary for the two bands to match and allow for current flow. The energy difference between the two sides is what creates the necessary gradient for electrons to move between them.
  • #1
fisico30
374
0
Hello Forum,

I am looking at the energy levels between the n and p regions of a diode. The p-side has a conduction band that starts at a higher energy (same for the valence band).
The n-side has the valence and condution bands that are at lower energy.

The Fermi energy line is the same for both...

I don't understand what happens to the energy level of the conduction band when the diode is forward biased...
does the conduction band of the p side gets lower and the conduction band of the n-side gets higher? Why? Do they need to match?

thanks
fisico30
 
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  • #2
I guess I am talking about the energy gradient that an electron in the n-side needs to climb...

Does forward biasing reduce that energy difference? Why does that energy difference exist?

Again, The valence band and conduction band in N-Type material are slightly lower than that of P-Type material.
 
  • #3
Or is the tension on the string that plays the role of the centripetal force?
 

What is a Pn junction?

A Pn junction is a type of semiconductor junction formed between a P-type semiconductor and an N-type semiconductor. It acts as a diode, allowing current to flow in only one direction.

What is a diode?

A diode is a two-terminal electronic component that allows current to flow in only one direction. It is made of a semiconducting material, such as silicon, with P-type and N-type regions connected together to form a Pn junction.

How does forward biasing affect the energy level of the conduction band?

Forward biasing occurs when the positive terminal of a battery is connected to the P-type region and the negative terminal is connected to the N-type region. This causes a decrease in the energy barrier between the P-type and N-type regions, allowing electrons to flow from the N-type region to the P-type region. As a result, the energy level of the conduction band in the P-type region increases while the energy level in the N-type region decreases, creating a flow of current.

What is the purpose of forward biasing a Pn junction?

The purpose of forward biasing a Pn junction is to allow current to flow through the diode. This is useful in electronic circuits, as it can be used to control the flow of electricity and create various functions, such as rectification and switching.

What happens to the current in a Pn junction during forward biasing?

During forward biasing, the current in a Pn junction increases as the energy barrier between the P-type and N-type regions decreases. This causes a flow of electrons from the N-type region to the P-type region, creating a current flow. The amount of current that can flow through the diode is dependent on the amount of forward bias voltage applied.

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