How do the effects of semiconductor doping affect the Hall effect?

In summary, the effects of semiconductor doping can affect the Hall effect by altering the concentration and mobility of charge carriers. This can lead to changes in the direction of deflection on a galvanometer and can also impact the reading on a voltmeter, depending on the type of doping used.
  • #1
Turion
145
2
How do the effects of semiconductor semiconductor doping affect the Hall effect?

For instance, consider number 4 and 5 in the following sample:

PP8Eo.png


Using the right hand rule, B points downwards, conventional current points to the right (because of the 5V battery), and therefore, the force on electrons points into the page. Electrons are going into the page from the red wire to the black wire and conventional current is going from the black wire to the red wire. But when conventional current goes from ground (black wire) to the higher voltage (red wire), then the voltage must be negative. Therefore, the voltmeter would read a negative reading.

However, I am unsure what kind of effects doping the semiconductor would have on the voltmeter.
 
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  • #2
Electrons are going [...]
That is just one option. Holes can go as well. What does conduct in p-doped semiconductors?
 
  • #3
If you look up the Hall effect on Wikipedia you will see that the Hall coefficient for semiconductors depends on the concentration of the two types of charge carriers as well as their respective mobilities. N doping means electron charge carriers predominate. Look at their expression for the Hall coefficient in a semiconductor at intermediate magnetic fields. You can deduce the direction of deflection of the galvanometer from the sign of the Hall coefficient.
 

1. How does doping affect the Hall coefficient?

Doping, the process of intentionally introducing impurities into a semiconductor material, can greatly affect the Hall coefficient. The Hall coefficient is a measure of the strength and direction of the magnetic field produced by the motion of charge carriers. Doping can alter the number and type of charge carriers, thereby changing the Hall coefficient.

2. What types of doping can affect the Hall effect?

Both n-type and p-type doping can affect the Hall effect. N-type doping, which involves adding impurities with extra electrons, increases the number of negative charge carriers and results in a decrease in the Hall coefficient. P-type doping, which involves adding impurities with fewer electrons, decreases the number of negative charge carriers and results in an increase in the Hall coefficient.

3. How does the concentration of dopants affect the Hall effect?

The concentration of dopants can have a significant impact on the Hall effect. As the concentration of dopants increases, the number of charge carriers also increases, resulting in a decrease in the Hall coefficient. This is because more charge carriers are available to contribute to the magnetic field, making it stronger.

4. Can doping affect the mobility of charge carriers?

Yes, doping can affect the mobility of charge carriers, which is the measure of how easily they can move through a material. Introducing impurities can scatter the charge carriers, making it more difficult for them to move and decreasing their mobility. This can also affect the Hall coefficient, as the strength of the magnetic field produced by the charge carriers is directly related to their mobility.

5. How does the temperature affect the Hall effect in doped semiconductors?

The temperature can also affect the Hall effect in doped semiconductors. As the temperature increases, the thermal energy causes more charge carriers to become excited and move around, resulting in an increase in the Hall coefficient. This is because more charge carriers are contributing to the magnetic field. Additionally, the mobility of charge carriers decreases with increasing temperature, which can also impact the Hall coefficient.

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