Conductors, semiconductors and insulators can be distinguished on the ground of their conductivity and other properties. Conductors like metals show conductivity at room temperature, but as the temperature increases, their conductivity gets reduced.
However, semiconductors act as the insulators at low temperature but as the temperature increases so their conducting properties also; however, insulators have no such effect of temperature variations as they do not have the conducting properties.
Insulators and conductors can be solid, liquid or gas, and in some exceptions like glass (solid) which is an insulator becomes conductors when melted at the higher temperature. On the other hand, semiconductors are present in the solid form.
Liquids can be conductors or insulators, depends on other properties. Though absolute pure water is an insulator, the liquid metals are electrically conductive. Gases also become electrically conductive when ionized, though they usually are insulators.
Conductivity is the phenomenon of transmitting something like heat, electricity or sound. So, based on the conductivity of any material and the presence of a forbidden gap, they (materials) can be classified as conductors, semiconductors or insulators. In the article, we will be differentiating the three terms concerning other points on which they vary.
Content: Conductors Vs Semiconductors Vs Insulators
|Basis for Comparison
|Conductors are the substance that transmits heat or electricity through them.
|Such substance or materials that may act as a conductor, as well as insulators under different conditions, are known as semiconductors.
|Insulators are the substance that does not allow heat or electricity to pass through them.
|There is no forbidden gap.
|Small forbidden gap.
|Large forbidden gap.
|Numerous electrons for conduction.
|Very less number of electrons for conduction.
|Neutral number of electrons for conduction.
|Caused by the presence of free electrons.
|It is caused by free electrons and holes.
|It is caused by free electrons which are negligibly present.
|There is only one valence electron in the outermost shell.
|There are four valence electrons in the outermost shell.
|There are eight valence electrons in the outermost shell.
|Overlapping of bands
|The valence and conduction bands are overlapped.
|Valence band and conduction band are separated energy gap of 1.1eV.
|Both the bands get divided by an energy gap of 6eV - 10eV.
|Type of Bonds
|Conductors are formed by a metallic bonding.
|Semiconductors are formed by covalent bonding.
|Insulators are formed by ionic bonds.
|Gold, Bronze, Silver, Mercury, Copper, Brass, etc.
|Mica, Rubber, Wood, Paper, etc.
Definition of Conductors
The materials or the substances that allow the electricity to flow through them are known as conductors. The process occurs because conductors enable the electrons to flow from one atom to others by an application of voltage. The phenomenon of transferring the heat or electricity in any substance is known as conductivity.
Electrical conductors can be metals, non-metals (conductive polymer and graphite), metal alloy, and electrolyte. Gold, Aluminium, Steel, Copper and Brass are the typical examples, which we encountered in our day to day life, and the most common is the pure elemental silver. As said above, conductors are mostly solid metals, that are moulded into the wires or incised onto the circuit boards.
Mercury is the best examples in case of liquids as a conductor. Gases are poor conductors, but when ionized they can become good conductors. So we can say that earth, animal, humans body, and metals are the conductors, that allow transition of heat and electricity from one point to other.
Applications of Conductors
- Iron is used in the manufacturing of the vehicle engine to conduct heat.
- The iron plate is made up of steel to absorb more heat.
- Aluminium is used in cooking utensils, that absorb and store heat, and even they are used in packing the food.
- Mercury is used in measuring the temperature of the body and is used in thermometer.
Definition of Semiconductors
Materials that have the characters to behave like conductors, as well as insulators under different conditions, are known as semiconductors. We can also say that such materials whose conductivity lies between conductors and insulators (nonconductors).
Semiconductors are used in the making of the various electronic devices like transistors, integrated circuits and diodes. These devices are reliable, low cost, easy to use, and power and efficient. Germanium, Silicon, Tellurium, Tin, and other metal oxides are a few examples of semiconductors.
Application of Semiconductors
Semiconductors are used in power devices, light emitters (including solid-state lasers), optical sensors. As they have voltage and current handling capabilities, and they are considered as future elements in manufacturing electronic devices like industrial-control equipment, communication with data-processing, etc.
Definition of Insulators
Insulators are the substances whose characters are different from the conductors, as they do not allow heat or electricity to pass through them. The reason for not allowing the heat or electricity to flow is the substance resistivity, and they don’t have any free electrons also.
Insulators are mostly solid. Glass, Mica, Rubber, Quartz, Wood, Wool, Plastic are some of the typical examples of insulators. One of the significant advantages of the insulators is that they act as the protectors against heat and electricity and form sound too.
Application of Insulators
- Rubber is commonly used as fire-resistant clothes, tyres, slippers as they are good insulators.
- Electrical insulators are used in the high-voltage system, electric circuits boards as they (insulating materials) hinder the flow of electrons as well current through them.
- Insulating materials are also covered over the electric cables and wires.
- Woollen clothes and blankets that are used in winters to keep the body warm.
Key Differences Between Conductors, Semiconductors and Insulators
Below given points will highlight the common though significant differences between conductors, semiconductors and insulators:
- Conductors are the substance or material that transmit heat or electricity through them. Such elements or materials that may act as a conductor, as well as insulators under different conditions, are known as semiconductors, whereas Insulators are the substance or material that does not transmit heat or electricity to through them.
- Conductors have high conductivity, while semiconductors have moderate and insulators have low (negligible) conductivity.
- Forbidden gap (the gap between the valence band and conduction band) is not found in conductors, while there is a small forbidden gap in semiconductors and the large forbidden gap is seen in insulators.
- Resistivity (the property of the resistance to measure the electrical conduction), which is low or negligible in conductors and very high in insulators, while moderate in semiconductors.
- Conductivity value (higher is the conductivity value, the lower is the substance resistivity) is 10-7mho/m (very high) of the conductors, whereas semiconductors have the value between 10-7mho/m to 10-13mho/m and insulators have 10-13mho/m (negligible).
- Resistivity value of the conductors is less than 10-5 Ω-m, while the semiconductors hold the value between 10-5 Ω-m to 105 Ω-m and insulators is having more than 105 Ω-m.
- There is only one valence electron in the outermost shell in conductors, though there are four valence electrons in the outermost shell of the semiconductors and there are eight valence electrons in the outermost shell of the insulators.
- Conductors are formed by metallic bonding; Semiconductors are formed by covalent bonding; Insulators are formed by ionic bonds.
- Gold, Bronze, Silver, Mercury, Copper, Brass, etc., are the few commonly used conductors, whereas Silicon, Aluminium, Tin, Germanium are the semiconductors; Mica, Rubber, Wood, Wool, Paper, etc., are widely used insulators.
In this article, we discussed three types of materials – Conductors, semiconductors and insulators. These are mainly differentiated based on electrical conductivity and other related properties. It is essential to know about them as these items are used in our day-to-day life, and materials like superconductors have a wide range of applications in manufacturing future electronic items.