Semiconductors

Flashcards covering the properties, types, and applications of semiconductors and related electronic components.

What is a conduction band?

The distance from the nucleus where an electron can escape and move freely.

What are electronic switches?

Devices that control the flow of electricity.

What are conductors?

Allow the flow of electrons within the structure; contain free electrons loosely attached to the atom where the valence band overlaps the conduction band.

What are insulators?

Materials with no free electrons, where electrons in the valence shell are strongly bonded and the energy level of the valence band is not close to the conduction band.

What is a semi-conductor?

Material with electrical properties halfway between insulators and conductors (e.g., silicon, germanium, gallium arsenide).

What is doping?

Adding small amounts of different elements with either more or less electrons in the outer shell to modify semi-conductors' electrical conductivity.

What is N-type semi-conductor?

Semi-conductor doped with donor impurities; contains spare, negatively charged electrons.

What is P-type semi-conductor?

Semi-conductor doped with acceptor impurities; contains spare, positively charged electrons.

What are diodes?

A device made by joining N-type to P-type doped semiconductors, allowing electrical current to flow in one direction.

What is a depletion layer?

Occurs when N-type and P-type semiconductors join, depleting free charge carriers.

What are photodiodes?

Semi-conductor that converts light into electrical current; a fast switch activated by light.

What is a transistor?

Two diodes with three layers of semi-conductors; acts as a fast, small electron switch.

What are integrated circuits?

Transistors made small using advanced printing techniques.

What is a Charged Coupled Device (CCD)?

Grid of photodiodes that converts light into a grid of varying electrical charge, capturing a digital image.

What is Complementary Metal Oxide Semi-conductor (CMOS)?

Differs from CCD due to manufacturing process and signal readout method; features faster photosites with local processing.