What is a Semiconductor? Examples of Semiconductors | Types of Semiconductors | Uses of Semiconductors

Semiconductors | Types of Semiconductors | Uses of Semiconductors

What is a Semiconductor?

A semiconductor is a material whose electrical conductivity lies between that of a conductor (like copper, which conducts electricity easily) and an insulator (like rubber, which does not conduct electricity). This means it conducts electricity only under specific conditions such as certain temperature, voltage, or when impurities are added.

The most important feature of a semiconductor is that its conductivity can be controlled — which is why it is used in electronic components like transistors, diodes, and integrated circuits (ICs).

Examples of Semiconductors

1. Silicon (Si) – The most commonly and widely used semiconductor.

2. Germanium (Ge) – Used in earlier types of circuits.

3. Gallium Arsenide (GaAs) – Used in high-speed electronic devices.

Types of Semiconductors

There are two main types of semiconductors:

1. Intrinsic Semiconductor

This is a pure form of a semiconductor without any added impurities. That means it is 100% natural, like pure silicon or pure germanium.The conductivity of intrinsic semiconductors is quite low because they have very few free electrons available to carry current.

👉 Examples: Pure Silicon, Pure Germanium

2. Extrinsic Semiconductor

When impurities are added to an intrinsic semiconductor to improve its conductivity, it becomes an extrinsic semiconductor. This process is called doping.

There are two types of extrinsic semiconductors:

A. N-type Semiconductor

Atoms with extra electrons (like phosphorus) are added.These extra electrons help in conduction.

👉 Majority charge carriers = Electrons

B. P-type Semiconductor

Atoms with one less electron (like boron) are added, which creates an empty spot or hole.These holes behave like positive charges and help in conduction.

👉 Majority charge carriers = Holes

Uses of Semiconductors

Today, semiconductors are everywhere — almost every modern electronic device is based on semiconductor technology.

In Electronics and Gadgets:

• Mobile phones – Processors and memory chips are made of semiconductors.

• Computers/Laptops – CPU, RAM, SSD, etc., are all made from semiconductors.

• Television and Radios – Use semiconductor circuits for signal processing.

• Washing machines, microwave ovens – Use semiconductor-based control circuits.

In Communication Systems:

• Transistors, diodes, and ICs – All are semiconductor components used for signal amplification and switching.

• Wi-Fi and Bluetooth chips – Enable wireless communication.

In the Energy Sector:

• Solar cells – Convert sunlight into electricity using semiconductors like silicon.

• LEDs (Light Emitting Diodes) – Use semiconductors for efficient lighting.

In Medical and Industrial Equipment:

• MRI machines, digital thermometers, and industrial robots — all use semiconductors in their systems.

Conclusion

Semiconductors are a revolutionary invention that have completely transformed the electronics industry. The devices we use daily — mobile phones, computers, TVs, washing machines, even electric vehicles — all have semiconductors at their core.

Their greatest advantage is that we can control their electrical behavior, which is why semiconductors are also crucial in futuristic technologies like Artificial Intelligence (AI), Internet of Things (IoT), 5G, and Robotics.