Semiconductors

Question 1

Semiconductor

Answer 1

Material that’s electrical properties lie between conductors and insulators

Question 2

Examples of semiconductors

Answer 2

Silicone, Germanium

Question 3

Intrinsic conduction

Answer 3

Movement of charge through a pure semiconductor

Question 4

Extrinsic conduction

Answer 4

Movement of charge through a doped semiconductor

Question 5

Doping

Answer 5

Addition of small amounts of impurities to semiconductor to increase conductivity

Question 6

n-type

Answer 6

Semiconductor in which electrons are the majority charge carriers. Material is negatively charged.

Question 7

p-type

Answer 7

Semiconductor in which holes are the majority charge carriers. Material is positively charged.

Question 8

Silicon acts as a perfect insulator when?

Answer 8

At 0 Kelvin

Question 9

How does a free hole come about

Answer 9

Heat added, atoms gain energy and electrons become free, free hole remains in place of electron

Question 10

Describe intrinsic conduction

Answer 10

When crystal lattice has free electrons, current can flow if it’s connected to a circuit. Electrons move to positive of battery. Free holes are positive and move to negative battery terminal.

Question 11

Example of n-type doping

Answer 11

Introduce phosphorus atoms to silicon lattice. Phosphorus has 5 electrons. Free electron introduced

Question 12

Example of p-type doping

Answer 12

Introduce boron atoms to silicon lattice. Boron has 3 electrons in its valence shell. Free hole introduced

Question 13

Diode

Answer 13

Electric device created by bringing together a p-type and n-type region within the same semiconductor lattice

Question 14

Uses of diodes

Answer 14

Rectifiers, LED