Contents
- 1 How does the built-in potential barrier depend on the doping concentration in PN junction?
- 2 How do you calculate built-in potential?
- 3 What happens if n and p-type materials are in close contact?
- 4 What is potential barrier in pn junction?
- 5 How barrier potential is created?
- 6 What is the relationship between doping and depletion region width?
- 7 What is the effect of doping on PN diodes?
How does the built-in potential barrier depend on the doping concentration in PN junction?
If the concentration of doping is increased, number of charge carriers also increases. Due to increased number of charge carriers, amount of diffusion increases and in turn, recombination of holes and electrons increases. Hence, we get a larger region depleted by charge carriers i.e. potential barrier increases.
How does barrier potential depends on doping?
It also depends on temperature and the doping concentration of the diode. Since the barrier potential depends on the width of the depletion region, the barrier potential depends on temperature, forward bias and the doping density of the diode. Therefore, the barrier potential does not depend on the design of the diode.
How do you calculate built-in potential?
The built-in potential (at 300 K) equals fi = kT/q ln(1016 x 9 x 1017/ni2) = 0.77 V, using kT/q = 25.84 mV and ni = 1010 cm-3. The built-in potential (at 100°C) equals fi = kT/q ln(1016 x 9 x 1017/ni2) = 0.673 V, using kT/q = 32.14 mV and ni = 8.55 x 1011 cm-3 (from Example 20).
What is built-in potential?
Equilibrium (zero bias) In a p–n junction, without an external applied voltage, an equilibrium condition is reached in which a potential difference forms across the junction. This potential difference is called built-in potential .
What happens if n and p-type materials are in close contact?
When P-type and N-type come into contact, carriers, which are holes and free electrons, are attracted to each other, recombine at the junction of P-type and N-type, and disappear. Because there are no carriers near the junction, it is called a depletion layer, and it becomes the same state as an insulator.
What does barrier potential depend on?
Barrier potential depends on the material used to make p-n junction diode (whether it is Si or Ge). It should also depend on the amount of doping due to which the number of majority charge carriers will change. Also, it depends on temperature due to which the number of minority carriers will change.
What is potential barrier in pn junction?
The potential barrier in the p-n junction is a type of barrier which does not allow the normal flow of charge across the junction and this resistance to the flow of charge is known as barrier potential.
What is built-in potential barrier?
The significance of this built-in potential across the junction, is that it opposes both the flow of holes and electrons across the junction and is why it is called the potential barrier. The result of this process is that the PN junction has rectifying current–voltage (IV or I–V) characteristics.
How barrier potential is created?
Barrier Potential: The electric field formed in the depletion region acts as a barrier. External energy must be applied to get the electrons to move across the barrier of the electric field. The potential difference required to move the electrons through the electric field is called the barrier potential.
What is effect of Gauss doping profile on electric potential?
This study aimed to determine the effects of Gauss doping profile on electric potential of p-n diode. This effect is studied by simulating PN diodes at equilibrium condition with differences in doping fall-off constant (dfc) using MATLAB and COMSOL software.
What is the relationship between doping and depletion region width?
I could only find the relationship between the depletion region width and the doping concentration. I don’t know how you missed the first formula for the built in voltage that I can find.
How are doping concentrations related to turn on voltage?
To answer this question, we use the equation relating to doping concentrations and turn on voltage to find the turn on voltage, and our relationship between the two depletion regions in order to solve for one. I chose to solve for the (x2-x1) first, using my calculator to solve the quadratic formula.
What is the effect of doping on PN diodes?
This effect is studied by simulating PN diodes at equilibrium condition with differences in doping fall-off constant (dfc) using MATLAB and COMSOL software. According to the simulation results, it concluded that p-n diode with different Gaussian doping profile, will produce similar built-in voltage (VGbi).