Semiconductors and Insulators

One of the most common methods for understanding variances in conduction is to use band theory. This explains a variety of physical features of conduction using the ‘band’ of material.

Within the limits of energy, electrons orbit the positive nucleus of a particular atom. The energy levels of many atoms reorganize into two bands, the valence band and the conduction band. The lower level of electrons is called the valence band, whereas the upper level is called the conduction band.

Between the bands, there is an energy gap where electrons can’t exist. Conduction happens when electrons move, and for this to happen, spaces in the energy bands must exist for the electrons to travel into.

Semiconductors

A semiconductor with intermediate conductivity has a conductivity value that falls between that of a conductor like silver and that of an insulator like the mica used in Elmelin’s product line.

As a semiconductor’s temperature rises, so does its resistance. Silicon (Si), germanium (Ge), and selenium (Se) are examples of semiconductor elements, as are compounds such as gallium arsenide (GaAs) and indium antimonide (InSb). The most common semiconductor is silicon.

In a semiconductor, there is a gap between the valence and conduction bands, but it is small enough to allow electrons to flow freely at ambient temperature, allowing for some conduction.

Because more electrons have the energy to travel into the conduction band as the temperature rises, a semiconductor’s conductivity increases. Because of the gap between atoms, gases are poor conductors by nature. Gasses, on the other hand, can be good conductors and behave as semiconductors in certain circumstances, such as when they contain a lot of ions.

Insulators

The flow of energy between two things is prevented by an insulator. Insulators, for example, can stop electricity, heat, or sound from flowing.

Thermal insulators prevent heat from being transferred between two things that are at different temperatures. This is accomplished using thermal insulators, which reflect heat energy. The inverse of thermal conductivity (k) is a material’s insulative capacity, hence materials with low thermal conductivity have a high insulating capacity or resistance value. Product density (ρ) and specific heat capacity (©) are also significant properties to think about.

A dielectric material is a non-conducting substance. Electric charges do not pass through these substances as they would via a conductor when they are polarized by an applied electric field.

As a result, the overall field within the dielectric is reduced by the internal electrical field.

Between the conduction and valence bands, there are bigger gaps in insulators. The material cannot conduct because electrons cannot move into the conduction band.

Semiconductors

The electrical conductivity of a semiconductor material is somewhere between that of a conductor, such as metallic copper, and that of an insulator, such as glass. As the temperature rises, its resistivity decreases; metals, on the other hand, exhibit the reverse behavior. By injecting impurities (“doping”) into the crystal structure, the conductivity of the material can be changed in useful ways. A semiconductor junction is formed when two distinct doped regions of the same crystal occur. Diodes, transistors, and most modern electronics are based on the behavior of charge carriers, which include electrons, ions, and electron holes, at these junctions. Silicon, germanium, gallium arsenide, and elements near the “metalloid staircase” on the periodic table are some examples of semiconductors. Gallium arsenide, the second most prevalent semiconductor after silicon, is used in laser diodes, solar cells, microwave-frequency integrated circuits, and other applications. Silicon is used to make the majority of electrical circuits.

Semiconductor devices can have a variety of useful qualities, such as the ability to transmit current in one way more easily than the other, changeable resistance, and light or heat sensitivity. Devices manufactured from semiconductors can be utilized for amplification, switching, and energy conversion because the electrical properties of a semiconductor material can be adjusted by doping and the application of electrical fields or light.

Examples of Semiconductors

Semiconductors include non-stoichiometric chemicals. The number of cations and anions in a non-stoichiometric compound differs. Overall electroneutrality is found in crystal lattices. Some of the cations in the crystal lattice must have a larger positive charge if there is a cation deficit. Cation-deficient non-stoichiometric semiconductors include ferrous oxide (FeO), ferrous sulfide (FeS), and copper oxide (Cu₂O). The lost electrons are trapped in the lattice if there is an anion shortage caused by excess metal ions. Non-stoichiometric anion deficient semiconductors like zinc oxide (ZnO) and cadmium oxide (CdO) are examples.

An electrical insulator is a substance that prevents electric current from freely flowing. The electrons in the insulator’s atoms are closely bonded and can’t easily travel. Other materials, such as semiconductors and conductors, are better at carrying electric current. Insulators have a higher resistance than semiconductors or conductors, which distinguishes them. Non-metals are the most common example.

Insulators support and separate electrical wires without allowing current to flow through them in electrical equipment. Insulation is a mass insulating material used to cover electrical cables or other equipment. Insulating supports used to connect electric power distribution or transmission and distribution to utility poles and transmission towers are referred to as insulators. They bear the weight of the dangling wires while preventing current from flowing through the tower to earth.

Conclusion

Electrical conductors are materials or items that allow current to flow in one direction alone. Copper, aluminum, and iron are among the best conductors. Electrical conductivity is a property of semiconductors, which are solid substances. As a result of this feature, it is suitable for controlling electrical current.

Finally, we can deduce from the given facts that the conductor has zero resistance, whereas semiconductors allow for current flow control. This characteristic is used to develop semiconductor-based real-time electronic circuits.