Understanding Extrinsic Semiconductors

What is the primary purpose of doping in semiconductors?

• To increase the size of the semiconductor

• To change the color of the semiconductor

• To alter the electrical conductivity

• To decrease the weight of the semiconductor

What are the two types of charge carriers in semiconductors?

• Photons and quarks

• Ions and atoms

• Free electrons and holes

• Protons and neutrons

How can the number of free electrons in a semiconductor be increased?

• By adding pentavalent atoms

• By adding divalent atoms

• By adding trivalent atoms

• By adding hexavalent atoms

What is a characteristic of pentavalent atoms?

• They have six valence electrons

• They have three valence electrons

• They have four valence electrons

• They have five valence electrons

Why are pentavalent atoms referred to as donor impurities?

• They neutralize the silicon crystal

• They accept electrons from the silicon crystal

• They donate free electrons to the silicon crystal

• They remove electrons from the silicon crystal

What happens to the extra electron from a pentavalent atom in silicon?

• It is absorbed by the silicon atom

• It becomes a free electron

• It is lost to the environment

• It forms a new covalent bond

What is the effect of lightly doping a semiconductor?

• It increases the semiconductor's weight

• It decreases the semiconductor's resistance

• It increases the semiconductor's resistance

• It changes the semiconductor's color

What is the resistance property of a heavily doped semiconductor?

• No resistance

• Variable resistance

• Low resistance

• High resistance

Why is doping important in constructing transistors?

• It changes the transistor's shape

• It alters the transistor's color

• It increases the transistor's size

• It adjusts the resistance properties

What distinguishes a lightly doped semiconductor from a heavily doped one?

• The color of the semiconductor

• The type of semiconductor material

• The size of the semiconductor

• The amount of impurity added