Semiconductor Theory

Holes in an n-type semiconductor are

majority carriers that are thermally produced

minority carriers that are produced by doping

minority carriers that are thermally produced

majority carriers that are produced by doping

When a pentavalent impurity is added to a pure semiconductor, it becomes ………

An insulator

n-type semiconductor

An intrinsic semiconductor

p-type semiconductor

Each atom in a silicon crystal has

four valence electrons

four conduction electrons

no valence electrons because all are shared with others atoms

eight valence electrons because all are with other atoms

N type semiconductor is obtained by adding:

Antimony

Boron

Indium

Gallium

A pn junction is formed by

the collision of a proton and a neutron

ionization

the recombination of electrons and holes

the boundary of a p-type and an n-type material

Single-element semiconductors are characterized by atoms with ____ valence electrons

5

4

2

3

In an N-type semiconductor, the concentration of minority carriers mainly depends upon

the temperature of the material

the doping technique

the number of donor atoms

the quality of the intrinsic material, Ge or Si.

Most widely used semiconductor in electronics is:

Carbon

Mica

Silicon

Quartz

A positive ion is formed when

valence electron breaks away from the atom

an atom gains extra valence electron

two atoms bond together

there are more holes than electrons in the outer orbit

Which of the following doping will produce a p-type semiconductor

Silicon with Germanium

Germanium with Antimony

Silicon with Indium

Germanium with phosphorus

Recombination is when

a valence electron becomes a conduction electron

an electron falls into a hole

a crystal is formed

a positive and a negative ion bond together

Doping materials are called impurities because they

Decrease the number of charge carriers.

Make semiconductors less than 100 percent pure.

Alter the crystal structures of the pure semiconductors

Change the chemical properties of semiconductors

Electron-holes pairs are produced by

thermal energy

ionization

doping

recombination

The purpose of a pentavalent impurity is to

increase the number of free electrons

increase the number of holes

reduce the conductivity of silicon

create minority carriers

What types of impurity atoms are added to increase the number of conduction-band electrons in intrinsic silicon?

trivalent

bivalent

octavalent

pentavalent

Doping of a semiconductor material means

that all impurities are removed to get pure silicon

that impurities are added to increase the resistance of the material

that impurities are added to decrease the resistance of the material.

that a glue-type substance is added to hold the material together

The movement of free electrons in a conductor is called

CurrenT

voltage

recombination.

equilibrium.

The atomic number of germanium is

8

32

16

4

At room temperature, the current in an intrinsic semiconductor is due to

ions

holes and electrons

holes

electrons

Avalanche breakdown results basically due to

impact ionisation

strong electric field across the junction

rise in temperature

emission of electrons