Introduction to Semiconductors

These flashcards cover key concepts and definitions from the lecture on semiconductors, including types of materials, conduction theory, current types, doping, n-type and p-type semiconductors, and the pn junction.

What are the three types of materials in electronics?

Conductors, insulators, and semiconductors.

What is conduction in semiconductors explained through?

Electron and hole theory.

What types of semiconductors differentiate from each other?

N-type and P-type materials.

What happens when an intrinsic silicon crystal is heated?

Some valence electrons gain enough energy to jump to the conduction band, becoming conduction electrons.

What is created when an electron jumps to the conduction band?

A hole is left in the valence band.

What is an electron-hole pair?

For every electron that rises to the conduction band, there is one hole left in the valence band.

What is electron current in silicon produced by?

The movement of thermally generated free electrons.

What does hole current refer to?

Current in the valence band produced by valence electrons moving into nearby holes.

What are impurities added to intrinsic silicon to improve conductivity called?

Doping.

What type of atoms are added for n-type semiconductors?

Pentavalent atoms.

What are majority and minority carriers in n-type semiconductors?

Electrons are majority carriers; holes are minority carriers.

What type of atoms are used for p-type semiconductors?

Trivalent atoms.

What results when trivalent atoms bond with silicon in p-type semiconductors?

Holes are created when each trivalent atom is added.

What is the distinction between majority and minority carriers in p-type semiconductors?

Holes are majority carriers; conduction-band electrons are minority carriers.

What is formed at the junction of p-type and n-type semiconductors?

A pn junction.

What is the depletion region?

A layer at the pn junction depleted of charge carriers due to diffusion.

What is the barrier potential in a pn junction?

The voltage required to move electrons through the electric field across the depletion region.

What is the typical barrier potential for silicon at 25°C?

Approximately 0.7 V.