Materials Used in Electronic Devices

Introduction

In the ever-changing field of technology, electronic gadgets play an essential role in our daily lives by connecting people, providing convenience, and driving innovation. Behind the sleek designs of modern devices, manufacturers carefully select materials for their specific properties. This article explores the fascinating world of materials used to create electronic gadgets—from the tiniest circuits to the outer casings.

Futuristic circuit board with glowing blue cube and intricate pathways, illustrating materials in electronic devices. High-tech and innovative tone.

When atoms combine to form a solid crystalline material, they arrange themselves in a symmetrical pattern. In a semiconductor crystal structure, the atoms bond together through covalent bonds formed by the interaction of their valence electrons. Silicon forms such a crystalline structure and serves as a widely used semiconductor material.

All materials consist of atoms. These atoms determine a material’s electrical properties, including its ability to conduct electrical current. When discussing electrical behavior, we represent an atom by its valence shell and a core that includes all inner shells and the nucleus. Figure 1 illustrates this concept using a carbon atom. Engineers often use carbon in certain types of electrical resistors. The carbon atom contains four electrons in its valence shell and two electrons in its inner shell. Its nucleus holds six protons and six neutrons, giving it a +6 positive charge from the protons. The core, which includes the nucleus and the two inner-shell electrons, carries a net charge of +4 (from +6 for the protons and –2 from the inner electrons).

Diagram of an atom with a gray core labeled "+4" and a yellow orbit displaying six valence electrons, each shown as pink spheres labeled "-".

Figure 1

In terms of their electrical properties, materials can be classified into three groups

Conductors
Semiconductors
insulators
Plastics and Polymers
Printable and Flexible Materials

Now we discuss about all this three materials in detail.

1.Conductors

A conductor is a material that easily allows electrical current to flow. Most metals serve as good conductors. The best conductors—such as copper (Cu), silver (Ag), gold (Au), and aluminum (Al)—consist of single-element atoms that each have one loosely bound valence electron. When a small amount of energy is added, these atoms release their loosely held valence electrons, turning them into free electrons. In a conductive material, these free electrons move freely and carry electrical current.

2.Semiconductors

A semiconductor conducts electrical current at a level between that of conductors and insulators. In its pure (intrinsic) form, a semiconductor functions as neither a good conductor nor a good insulator. Single-element semiconductors include antimony (Sb), arsenic (As), astatine (At), boron (B), polonium (Po), tellurium (Te), silicon (Si), and germanium (Ge). Engineers also commonly use compound semiconductors such as gallium arsenide, indium phosphide, gallium nitride, silicon carbide, and silicon germanium. Atoms in single-element semiconductors each contain four valence electrons. Among them, silicon remains the most widely used semiconductor material.

3.Insulators

An insulator is a material that does not conduct electrical current under normal conditions. Most good insulators are compounds rather than single-element materials and have very high resistivities. Valence electrons are tightly bound to the atoms; therefore, there are very few free electrons in an insulator. Examples of insulators are rubber, plastics, glass, mica, and quartz.

4.Plastics and Polymers

PE, PP, PC are lightweight and versatile polymers used in device casings, battery housings, and other structural components. PC is known for impact resistance and commonly used in laptop and smartphone bodies. PET is transparent and lightweight, often used in flexible electronics and as a display substrate.

5.Printable and Flexible Materials

Organic semiconductors enable the development of flexible and printable electronics for creating bendable displays and sensors. Graphene, composed of a single layer of carbon atoms in a hexagonal arrangement, serves as a highly conductive material known for its exceptional strength and flexibility. This material shows potential for use in future flexible electronics and high-speed electronic devices.

Conclusion

Every day, we interact with electronic devices that rely on a carefully selected range of materials for their performance, durability, and innovation. The constant search for new materials pushes the limits of what is achievable, leading to more powerful, sustainable, and versatile electronic devices in the future.