What occurs after a few recombinations around the junction in a PN junction?
Click to see answer
A restraining force, known as the Barrier, is set up.
Click to see question
What occurs after a few recombinations around the junction in a PN junction?
A restraining force, known as the Barrier, is set up.
What is the condition for a PN junction to be considered reverse biased?
The positive terminal of the battery is connected to the N-side and the negative terminal to the P-side.
What prevents electrons from diffusing into the P-region?
The uncompensated -ve charge of immobile carriers in the P-region.
What are the three possibilities when voltage is applied across a semiconductor diode?
No Bias (V=0), Forward Bias (V>0), Reverse Bias (V<0).
What is the region containing uncompensated acceptor and donor ions called?
Depletion Region.
What is the barrier potential for Germanium (Ge)?
0.3V.
How many terminals does a semiconductor diode have?
Two terminals.
What do the P-region and N-region of a diode represent?
The P-region is called the Anode and the N-region is called the Cathode.
What happens to holes and electrons in a reverse-biased PN junction?
Holes in the P-region are attracted to the negative terminal, and electrons in the N-region are attracted to the positive terminal.
What charge is built on the P-side of the PN junction?
-ve charge.
What are P-type and N-type semiconductor materials used for?
They are used separately but have very limited use.
What is the current due to minority carriers called?
Reverse Saturation Current.
What happens in the p-type material during forward bias?
An electron breaks a bond and enters the positive terminal, creating a hole that drifts towards the junction.
What charge is built on the N-side of the PN junction?
+ve charge.
In which direction does conventional current flow in a forward-biased PN-junction?
From the p-side to the n-side.
How does the Reverse Saturation Current behave with changes in battery voltage?
It remains the same whether the battery voltage is increased or decreased.
In which direction does the arrow in the PN junction diode symbol point?
From the P-region to the N-region, indicating conventional current flow.
What is the barrier potential for Silicon (Si)?
0.7V.
What remains uncompensated when holes and free electrons recombine in a PN junction?
Negative acceptor ions in the P-region and positive donor ions in the N-region.
What occurs due to the negative potential applied to the N-side in forward bias?
Electrons are repelled from the negative terminal and move towards the junction.
What factors influence the generation of minority carriers?
Temperature, due to the breaking of covalent bonds with temperature rise.
What causes the diffusion of holes and electrons in a PN junction?
Thermal energy and different concentration levels in the two regions.
What is the restraining force that stops further diffusion of holes and electrons in a PN junction?
The Barrier or Potential Barrier.
What is the effect of the positive potential applied to the P-side in forward bias?
Holes are repelled from the positive terminal and move towards the junction.
What type of current flows through the external circuit in forward bias?
Electron current flows through the external circuit.
What effect does reverse bias have on the depletion region?
It widens the depletion region and increases the barrier potential.
How does the increased barrier potential affect majority carriers?
It makes it more difficult for majority carriers to diffuse across the junction.
What happens to minority carriers as soon as they are generated?
They are swept across the junction, allowing a very small current to flow.
What is the width of the barrier?
The physical distance from one side of the barrier to the other.
What happens to holes from the P-region when the PN junction is formed?
They diffuse into the N-region and combine with free electrons.
What happens in the case of no applied bias (V=0V)?
The diode is in a neutral state with no current flow.
What occurs during the recombination of electrons and holes in forward bias?
An electron from the negative terminal enters the n-type material and drifts towards the junction.
What assists minority carriers in crossing the junction in a reverse-biased diode?
The increased barrier potential.
Why is the Reverse Saturation Current very small?
Because the number of minority carriers is small.
What is the height of the barrier?
The difference of potential from one side of the barrier to the other.
What is a semiconductor diode?
A useful device formed by a PN-junction.
What happens to the depletion region when the PN-junction is forward biased?
The potential barrier reduces, and the width and height of the depletion region decrease.
What occurs to majority carriers when the PN junction is forward biased?
More majority carriers diffuse across the junction, increasing current.
What role does the Barrier play for minority carriers?
It helps them to drift across the junction.
What happens when a battery is connected to a PN-junction with the positive terminal to the P-side?
The PN-junction is said to be Forward Biased.
What happens to the barrier potential when battery voltage is increased?
The barrier potential is further reduced.
What prevents holes from diffusing into the N-region?
The uncompensated +ve charge in the N-region.
What are the two types of regions in a PN junction?
P-type and N-type.
What is formed when P-type and N-type materials are joined?
A PN-junction.
What are the typical values of Reverse Saturation Current in Ge and Si?
μA in Ge and nA in Si.
What is the symbol for a PN junction diode?
It resembles an arrow pointing from the P-region (Anode) to the N-region (Cathode).
Can majority carriers overcome the barrier?
Yes, but this does not mean that current flows since there is no circuit connected.
What is formed to prevent total recombination of holes and electrons?
The Barrier.
What is another name for the Depletion Region?
Space-Charge Region.
