Electrical Conductivity of Metals

Study Notes

Metals like silver, copper, aluminum, gold, and most other metals are excellent conductors of electricity due to their delocalized electrons.
Silver has the highest conductivity, followed by copper and aluminum.
These metals are widely used in electrical wiring, cables, and heat sinks.

Carbon in the form of graphite is an excellent conductor of electricity due to its structure, which allows three out of four carbon atoms to bond, leaving one electron free for bonding.

Conductors in their solution form are called ionic conductors.
Examples of ionic conductors include saltwater, which is a good conductor of electricity due to the movement of ions (charged atoms).

Electrical Wiring: Copper wires are widely used in electrical power transmission and distribution systems due to their high conductivity and ease of use.
Electronic Circuits: Copper traces are used in printed circuit boards (PCBs) to conduct electrical signals between components.
Heat Sinks: Aluminum heat sinks are commonly used in electronic devices to dissipate heat away from hot components like processors.
Electromagnets: Conductors are essential for creating electromagnets used in motors, transformers, and loudspeakers.
Other applications include car radiators, steam or press irons, baking tools, and auto parts industry.

Semiconductors are materials with conductivity between conductors (metals) and non-conductors (insulators).
Examples of semiconductors include gallium arsenide, germanium, and silicon.
Semiconductors can be used in electronic circuit fabrication, solar cells, laser diodes, and other applications.

Holes (valence electrons) are positively charged electric charge carriers, while electrons are negatively charged particles.
Electrons have higher mobility than holes due to their different band structures and scattering mechanisms.

The band theory explains the energy levels of electrons in an atom, which split into multiple levels when combined with other atoms in a solid.
The gap between adjacent bands represents a range of energies that possess no electron, known as the band gap.

Semiconductors act like insulators at zero Kelvin but work as conductors at higher temperatures.
Semiconductors can be modified by doping to make semiconductor devices suitable for energy conversion, switches, and amplifiers.
They have lesser power losses, are smaller in size, and possess less weight.

Intrinsic Semiconductor: Made of a single type of element, like germanium (Ge) and silicon (Si), which are the most common types of intrinsic semiconductor elements.