01_DIAG_PN JUNCTION

Question 1

What is a PN junction diode?

Answer 1

A basic semiconductor device that allows current to flow in only one direction.

Question 2

What are the two types of semiconductors used in a PN junction diode?

Answer 2

• P-type (positive)
• N-type (negative)

Question 3

What charge carriers are found in a P-type semiconductor?

Answer 3

Holes (positive charge carriers)

Question 4

What charge carriers are found in an N-type semiconductor?

Answer 4

Electrons (negative charge carriers)

Question 5

What is the depletion region in a PN junction diode?

Answer 5

The region where P and N materials meet, containing immobile ions and an electric field.

Question 6

What happens during forward bias in a PN junction diode?

Answer 6

• P connected to +
• N connected to -
• Decreases the width of the depletion layer
• Allows current to flow

Question 7

What happens during reverse bias in a PN junction diode?

Answer 7

• P connected to -
• N connected to +
• Increases depletion layer
• Blocks current (only a tiny leakage current flows)

Question 8

What is the voltage drop in the forward region for silicon and germanium diodes?

Answer 8

• Silicon: about 0.7V
• Germanium: about 0.3V

Question 9

What is observed in the reverse region of a PN junction diode?

Answer 9

Very small current until breakdown voltage.

Question 10

What is a PN junction?

Answer 10

A PN junction is a semiconductor device formed by joining P-type and N-type materials.

Question 11

True or False: The P-type semiconductor has an abundance of electrons.

Answer 11

False

Question 12

What charge carriers are majority in P-type semiconductors?

Answer 12

Holes

Question 13

Fill in the blank: The N-type semiconductor has an abundance of __________.

Answer 13

Electrons

Question 14

What happens at the junction of P-type and N-type materials?

Answer 14

Electrons from the N-type region recombine with holes in the P-type region, creating a depletion region.

Question 15

What is the depletion region in a PN junction?

Answer 15

The depletion region is an area around the PN junction where charge carriers are depleted, resulting in an electric field.

Question 16

True or False: A PN junction can conduct current in both directions.

Answer 16

False

Question 17

What is the forward bias condition in a PN junction?

Answer 17

When the P-side is connected to a higher voltage than the N-side, allowing current to flow.

Question 18

What is the reverse bias condition in a PN junction?

Answer 18

When the N-side is connected to a higher voltage than the P-side, preventing current flow.

Question 19

What is the built-in potential of a PN junction?

Answer 19

The built-in potential is the voltage across the depletion region when the junction is in equilibrium.

Question 20

Which law describes the current-voltage relationship of a PN junction?

Answer 20

The Shockley diode equation.

Question 21

What effect does temperature have on the PN junction?

Answer 21

Increasing temperature increases the intrinsic carrier concentration, affecting the current flow.

Question 22

Name a common application of a PN junction.

Answer 22

Diodes, such as rectifiers and signal diodes.

Question 23

True or False: A Zener diode is a type of PN junction that can operate in reverse bias.

Answer 23

True

Question 24

What is the role of doping in creating P-type and N-type semiconductors?

Answer 24

Doping introduces impurities to increase the number of holes (P-type) or electrons (N-type).

Question 25

Fill in the blank: The junction of P-type and N-type semiconductors is essential in the operation of __________.

Answer 25

Transistors

Question 26

What is the significance of the forward voltage drop in a PN junction?

Answer 26

It is the voltage required to overcome the built-in potential and allow current to flow.

Question 27

What happens to the current in a PN junction when the reverse bias voltage is increased?

Answer 27

The current remains very small, primarily due to leakage, until breakdown occurs.

Question 28

What is the breakdown voltage in a PN junction?

Answer 28

The voltage at which the PN junction begins to conduct significantly in reverse bias.

Question 29

True or False: Light-emitting diodes (LEDs) are a type of PN junction device.

Answer 29

True

Question 30

What is recombination in the context of a PN junction?

Answer 30

The process where free electrons fill holes, resulting in the release of energy, often as light or heat.

Question 31

What is the function of a photodiode?

Answer 31

A photodiode converts light into electrical current using the principles of a PN junction.

Question 32

Fill in the blank: The __________ region is formed when a PN junction is forward biased.

Answer 32

Conducting

Question 33

What is the primary characteristic of a Schottky diode compared to a standard PN junction diode?

Answer 33

A Schottky diode has a metal-semiconductor junction rather than a P-N junction, allowing for faster switching speeds.