What are Display Dielectric Materials - Properties and its Types?
A dielectric material is a non-conductor of electricity and these materials can be extremely polarized with the help of electric field to store electric charge. A dielectric material dissipates and stores the electrical charge similar to an ideal capacitor. There are two types of display dielectric materials polar and non-polar. The display dielectric materials are used in display applications such as OLED, LED, LCD, etc.
Materials are classified as insulators, conductors, and semiconductors on the basis of their electrical conducting properties. In the electric field, the atoms in the material experiences certain changes and displacements in properties. As per an experiment conducted by Ewald Georg von Kleist in October 1745, it showed that energy can be stored. Based on this experiment, Pieter van Musschenbroek invented ‘Leyden Jar’, which is said to be the first capacitor. ‘Dielectric’ was the next invention that backed the new material property.
Dielectric materials are substances that are poor conductor of electricity and these materials can be highly polarized with the help of electric field to store electric energy. The dielectric materials when placed in an applied electric field, the electric material can shift from equilibrium position due to non-passage of electricity to these materials. This displacement is called electrical polarization. As per Research dive analyst review, dielectric materials have electric everlasting dipole moment, which is a unit that can separate the positive and negative charges by a small distance. Dielectric materials are majorly used in display applications such as OLED, LED, LCD, and others.
Properties of Display Dielectric Materials
William Whewell was the first man to introduce the term Dielectric to the world, which is the grouping of two words- ‘Dia’ and ‘electric’. For a perfect dielectric material, the electrical conductivity is zero. A dielectric material dissipate and stores the electrical charge similar to an ideal capacitor. The major properties of a display dielectric material are dielectric polarization, electric susceptibility, dielectric dispersion, tenability, dielectric relaxation, etc.
• Dielectric Polarization
The electric dipole moment is a measure of separation of positive and negative charge in the system. When applied in an electric field, the connection between the electric field (E) and the dipole moment (M) gives rise to the dielectric properties and the items return to its original state. This time taken by the atom to reach to its original state is called as Relaxation time.
• Electric Susceptibility
Electric susceptibility is used to measure how easily the dielectric materials can be highly polarized when subjected to an electric field. The electric permeability of these materials can be determined by this quantity.
• Total Polarization
The two factors that re are two factors that choose the polarization of dielectric materials are:
- The formation of dipole moment and,
- Their direction related to the electric field.
On the basis of the elementary dipole type there can be either ionic polarization or electronic polarization. Pe (Electronic polarization) occurs when the dipole moment is composed of neutral particles. On the other hand, the electronic polarization or Pi (ionic polarization) both are independent of temperature.
• Dielectric Breakdown
The insulator starts behaving as a conductor when higher electric fields are applied. The dielectric properties are lost by dielectric materials in such conditions, which is known as Dielectric Breakdown. This process is irreversible as it leads to the non-performance of dielectric materials.
Types of Dielectric Material
On the basis of type of molecule present in the materials, the dielectrics are classified in two types - polar and non-polar dielectric materials.
1. Polar Dielectric Materials
In this type of dielectric materials, the center of mass of negative particles does not coincide with the center of mass of positive particles. The shape of the molecules is asymmetrical and the dipole moment here is present. The molecules align themselves when applying the electric field. However, a random dipole moment is detected when the electric field is removed, which results in the net dipole moment becoming zero. Examples are CO2, H2O, etc…
2. Non-Polar Dielectric Materials
In this type of dielectric materials, the center of mass of negative particles and positive particles coincide. There is a no presence of dipole moment in these molecules and they are symmetrical in shape. Examples are O2, N2, H2, etc.
Examples of Dielectric Materials
Dielectric materials can be vacuum, gases, liquids, and solids. The solid dielectric materials are widely used in electrical engineering. Some examples of these materials are glass, ceramics, porcelain, paper, etc. Oxides of several metals, nitrogen, dry air, and sulfur hexafluoride are some examples of gaseous dielectric materials. Transformer oil, distilled water are common examples of liquid dielectric materials.