Semiconductor physics: Voltage below forward voltage

In summary, the diode behaves in a way that contradicts the expectations based on the knowledge we currently have.
  • #1
CaptainMarvel1899
28
3
Assume we have a diode closed circuit.We connect the p type region of the diode to the positive terminal of the battery(cathode).We connect the n type region of the diode to the negative terminal of the battery(anode).The voltage of the battery is 0.3V .The diode%s intristic se miconductor is silicon.Here is my issue . The net force moves the electrons from the n type to the p type.But because there is not enough voltage the valence electrons of silicon have a slight propability to overcome the band gap and become free charge carriers.But if they don't become become free charge carriers they will form bonds with B-atoms because charges do move and fill Boron holes.And this would result to a bigger potential energy of the system.What am I missing?
 
Physics news on Phys.org
  • #2
Can you not just look at it as narrowing the depletion layer - in the same way that reverse bias will widen it? Work will have been done because the unbiased condition will be the lowest Energy situation.
 
  • #3
H
sophiecentaur said:
Can you not just look at it as narrowing the depletion layer - in the same way that reverse bias will widen it? Work will have been done because the unbiased condition will be the lowest Energy situation.
Widening of the depletion region in reverse bias does happen.Narrowing doesn't happen as you think it is happening.As voltage is increased the drift velocity of the free electrons is increased so they switch on and off the depletion region more frequently if the had less voltage , so less resistance.Also the depletion region is decreased by the applied voltage because electrons gain energy due to the the electric potential and have a bigger propability of becoming free charge carriers.So back to my question how do you explain this thing maybe the depletion region would be increased(not very much)by the movement of those carriers?
 
  • Informative
Likes sophiecentaur
  • #4
Idid a quick search but could find no data about the Capacitance of a varactor diode under forward bias. That would give a clue??
 
  • #5
Yes it gives me a clue.I will do some experiments on my own and tell you the results.
 

Related to Semiconductor physics: Voltage below forward voltage

1. What is a semiconductor?

A semiconductor is a material that has electrical conductivity between that of a conductor and an insulator. It is characterized by its ability to conduct electricity under certain conditions, such as exposure to light or application of an electric field.

2. What is the difference between a forward voltage and a voltage below forward voltage?

Forward voltage is the voltage at which a semiconductor begins to conduct electricity. A voltage below forward voltage refers to any voltage lower than this threshold, where the semiconductor does not conduct electricity.

3. Why is it important to understand voltage below forward voltage in semiconductor physics?

Understanding voltage below forward voltage is crucial in the design and operation of electronic devices, as it allows for precise control of the flow of electricity. It also plays a significant role in the study of semiconductor materials and their properties.

4. How does voltage below forward voltage affect the behavior of a semiconductor?

At voltages below forward voltage, a semiconductor will behave as an insulator, meaning it will not conduct electricity. This is due to the absence of free charge carriers, which are necessary for electrical conduction. As the voltage increases beyond forward voltage, the semiconductor will begin to conduct electricity and exhibit different properties depending on the type of semiconductor material.

5. Can voltage below forward voltage be manipulated or controlled in electronic devices?

Yes, voltage below forward voltage can be controlled through the use of external components such as resistors, diodes, and transistors. These components can alter the voltage and current flow in a circuit, allowing for precise control of the behavior of a semiconductor. This is essential in the design and functionality of electronic devices.

Similar threads

  • Electromagnetism
Replies
10
Views
4K
Replies
7
Views
1K
Replies
2
Views
1K
  • Classical Physics
Replies
10
Views
1K
  • Electromagnetism
2
Replies
36
Views
3K
Replies
14
Views
4K
  • Electromagnetism
Replies
1
Views
703
Replies
19
Views
3K
  • Electromagnetism
Replies
4
Views
1K
Replies
101
Views
7K
Back
Top