What are Conductors, Semiconductors, and Insulators?

Conductors, semiconductors, and insulators, the trio forms the most popular set of substances in electricity and its conductivity, and form one of the most exciting study materials in physics.

The basic difference among them is that conductors, semiconductors, and insulators is their conductivity levels of electricity. Conductors have a high conductivity, which implies they enable energy to flow easily through them, such as electricity, heat, or sound. Semiconductors allow for moderate flow, whereas insulators have poor conductivity.

As far as the basic difference is concerned, it is undoubtedly the levels or degree of conductivity of electricity. However, there are certain other differences with respect to their application, that clearly distinguish them from one another.

In this article, let us focus on

How does a conductor work

How does a semiconductor work

How does an insulator work

Besides, we shall throw light on examples of conductor, semiconductors and insulators

Band Theory

One of the important ways in which the differences in conduction may be explained is Band theory.  Since this uses the material ‘band’ to explain a variety of physical properties of conduction, it is called band theory.

In an individual atom, within the permissible energy levels, there are electrons that orbit its positive nucleus. Among the several atoms, the energy levels are reorganized in two bands, the valence band and the conduction band. The lower level of electrons is called the valence band while the conduction band refers to the higher level of electrons.

There is an energy gap occurring between the bands in which there is no existence of electrons. As and when the conduction occurs, these electrons get into motion, and this can be possible only when there are spaces in the energy bands for them electrons to enter and move.

What is a Conductor?

A conductor allows an electron to move easily from one atom to another when the right voltage is applied, as there are no band gaps between the valence and conduction bands.

Some materials’ conductor and valence bands overlap, allowing electrons to flow between the two overlapping bands. Because there is space for electrons to travel into the conduction band, one electron from the valence band moves into the other band, allowing conductivity.

Can we name on most popular conductor of electricity? Among several, silver is most likely the finest electrical conductor we come up with in daily life. Other metals with good conductivity include gold, copper, steel, aluminum, and brass. These materials can be found in ordinary electrical equipment, either as cables or etched onto circuit boards.

Although solids are often the best conductors, some liquids, notably liquid metals such as mercury, are equally effective at allowing energy to be transmitted through them.

What are superconductors?

Superconductors are certain materials that will conduct without resistance at extremely low temperatures.

Example of Conductor

Graphite, the human body, and the earth are all excellent electrical conductors. Metals that are good conductors are: 

• Silver 
• Gold 
• Copper 
• Steel 
• Aluminum 
• Brass 

What is a Semiconductor?

A semiconductor with moderate conductivity has a conductivity value between that of a conductor, such as silver, and an insulator. As a semiconductor’s temperature rises, its resistance decreases. Semiconductors include elements or metalloids such as silicon (Si), germanium (Ge), and selenium (Se), as well as compounds such as gallium arsenide (GaAs) and indium antimonide (InSb), from which Silicon is the most commonly used semiconductor.

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

A semiconductor’s conductivity increases as temperature rises because more electrons have enough energy to travel into the conduction band.

Because of the gap between atoms, gases are normally weak conductors. Gases, on the other hand, can be fair conductors and function as semiconductors under certain conditions, such as when they contain a significant number of ions.

Examples of Semiconductor

Some of the most prevalent semiconductors include: 

• Gallium arsenide 
• Germanium 
• Silicon 
• Selenium 

Importance of Semiconductor

Typically, s semiconductor is a substance that lies between the conductor and insulator. It plays an important role in regulating and maintaining the current flow in electronic equipment and devices. Semiconductor, with this inherent property, plays an unmatched role as a crucial component in chips that are used as computer components, smartphones, tabs, smart TVs, video games, medical equipment, and several other electronic devices, and solid-state storage.

These semiconductors, also termed as integrated circuits or microchips, are pure in their form. However, through a process called doping, mild doses of impurities are added to these, causing alterations in conductivity.

What is an Insulator?

An insulator restricts energy from flowing between two things. Insulators, for example, can restrict the flow of electricity, heat, or sound. 

Thermal insulators prevent heat from being transferred between two objects of different temperatures. Thermal insulators do this by reflecting heat. Because insulative capacity is the inverse of heat conductivity (k), materials with low thermal conductivity will have a high insulating capability or resistance value. Product density (ρ) and specific heat capacity © are also significant parameters to consider. 

A dielectric material is a substance that does not conduct electricity. An applied electric field can polarise certain substances, preventing electric charges from flowing through them as they would via a conductor. As a result, the internal electrical field decreases the total dielectric field. 

There are bigger gaps between the conduction and valence bands in insulators. Because electrons cannot travel into the conduction band, the material cannot conduct. 

Examples of insulator

The following are some examples of common insulators: 

• Plastic 
• Wood 
• Glass 

Differences between Conductors, Semiconductors, and Insulators

Conductors	Semiconductors	Insulators
Materials that allow electricity or heat to flow through them.	Materials that moderately allow the flow of heat or electricity.	Materials that do not allow the passage of heat or electricity.
Aluminium, Silver, and iron are examples of conductors.	Silicon (Si), germanium (Ge), and selenium (Se) are some examples.	Paper, wood, and rubber are all examples of insulators.
Electrons are free to migrate throughout the conductor.	Electrons have low mobility due to the higher atomic force.	Electrons cannot easily migrate within the insulator.
On the surface, there is an electric field, yet it is zero on the inside.	The electric field is inside and outside.	There is no such thing as an electric field.

Electrons are free to migrate throughout the conductor. Electrons have low mobility due to the higher atomic force. Electrons cannot easily migrate within the insulator.

On the surface, there is an electric field, yet it is zero on the inside. The electric field is inside and outside. There is no such thing as an electric field.

Conclusion

To learn more about conductors, semiconductors, and insulators, sign up for Tutoroot’s personalized learning sessions. Tutoroot is dedicated to assisting you in achieving the highest academic grades. Join us for engaging and simple-to-understand sessions. 

FAQ’s

What are Conduction and Insulation? 

A conductor that permits current to pass through it effortlessly is conduction. Insulators prevent electricity from flowing through them, which is insulation. 

What are examples of conductors?

In our daily lives, conductors find a regular, yet prominent place, in many ways:

They are: mercury in thermometers, radiators, and iron in cooking pans, to name a few

What are the examples of semiconductors?

These are all over, but are less identified since they are not as popular and obvious as conductors and insulators.

They are present in transistors where very large-scale integration, or VLSI technology powers small-sized transistors. Solar cells are also made up of semiconductors, and used in solar panels to produce electricity

What are the examples of insulators?

Wall insulation to control the flow of heat, sound insulation to block the sound waves and prevent disturbance, and power or electrical insulation in circuits and electrical systems, to name a few.

What is an example of a conductor and semiconductor?

Conductor: Copper

• Silver
• Aluminum
• Metals
• Gold
• Brass
• Iron
• Steel
• Graphite

Semiconductor:

Gallium arsenide, germanium and silicon are some of the most commonly used semiconductors

What are examples of insulators?

Glass, plastic, rubber, air, and wood, to list a few