Advanced Materials Engineering - Electrical Properties

These flashcards cover key terms and definitions related to electrical properties in materials engineering, particularly focusing on concepts relevant for understanding conductivity and semiconductor behavior.

Ohm's Law

The principle that states the current through a conductor between two points is directly proportional to the voltage across the two points.

Conductivity (σ)

A measure of a material's ability to conduct electric current, defined as the inverse of resistivity.

Resistivity (ρ)

A material property that quantifies how strongly a given material opposes the flow of electric current.

Electron mobility (μ)

The ability of an electron to move through a conductor or semiconductor when an electric field is applied.

Fermi Energy (Ef)

The highest energy level occupied by electrons in a solid at absolute zero temperature (0 K).

Intrinsic semiconductor

A pure semiconductor without any significant dopants, characterized by a narrow band gap.

Extrinsic semiconductor

A semiconductor that is doped with impurities to control its electrical properties.

Valence band

The highest energy band that is filled with electrons at absolute zero.

Conduction band

The energy level above the valence band where electrons are free to move, thus enabling electrical conduction.

Charge carrier

A particle (electron or hole) that carries electric charge, allowing current to flow in conductive materials.

Piezoelectric effect

The generation of an electric charge in certain materials when mechanical stress is applied.

Resistivity dependence factors

Factors affecting resistivity include temperature, impurities, dislocations, and grain boundaries.

Drift velocity

The average velocity of charge carriers due to an applied electric field.

Band gap

The energy difference between the valence band and conduction band in semiconductors, determining electrical conductivity.

Doping

The introduction of impurities into a semiconductor to alter its electrical properties, such as increasing its conductivity.

Mobility

The ratio of the drift velocity of the charge carriers to the applied electric field strength.

Thermal excitation

The process by which temperature causes charge carriers to gain enough energy to move to higher energy states.

Ionic conduction

The movement of ions in a liquid or solid that can carry charge, primarily in ionic materials.