A semiconductor is a material that has electrical conductivity between that of a conductor (like copper) and an insulator (like glass). Semiconductors are the foundation of modern electronics, enabling the creation of transistors, microchips, and computer processors.
Key Properties of Semiconductors
✔ Controlled Conductivity – Can act as a conductor or insulator depending on conditions.
✔ Band Gap Energy – The energy difference between the valence band (where electrons are bound) and the conduction band (where electrons move freely).
✔ Sensitive to Temperature & Light – Conductivity increases with heat or exposure to photons.
✔ Doping Enhances Performance – Adding impurities (doping) improves electrical behavior.
Types of Semiconductors
| Type | Description | Examples |
|---|---|---|
| Intrinsic (Pure) Semiconductors | Naturally weak conductors, conductivity depends on temperature. | Silicon (Si), Germanium (Ge) |
| Extrinsic (Doped) Semiconductors | Improved conductivity using added impurities. | N-type and P-type Silicon |
🔹 N-type Semiconductor → Extra electrons improve conductivity.
🔹 P-type Semiconductor → Extra “holes” (missing electrons) improve conductivity.
How Semiconductors Work in Electronics
- Doping Creates Charge Carriers
- N-type doping: Adds electrons (negative charge carriers).
- P-type doping: Creates “holes” (positive charge carriers).
- PN Junction Forms a Diode
- A PN junction allows current to flow in one direction only, forming the basis of diodes, transistors, and solar cells.
- Transistors Control Signals
- Semiconductors in transistors switch electrical signals on and off, forming the basis of computers and logic circuits.
Applications of Semiconductors
✔ Computing & Microprocessors – Semiconductors power CPUs, GPUs, and AI chips.
✔ Smartphones & Electronics – Essential for mobile devices, sensors, and cameras.
✔ Solar Panels – Photovoltaic cells convert sunlight into electricity using semiconductors.
✔ LEDs & Display Technology – Light-emitting diodes use semiconductors to emit light.
✔ Automobiles & Aerospace – Used in electric vehicles, aircraft, and radar systems.
Why Are Semiconductors Important?
✔ Enable Miniaturization – Moore’s Law states that transistor sizes shrink over time, increasing computing power.
✔ Drive AI & Quantum Computing – Advanced semiconductors power AI algorithms and quantum processors.
✔ Key to 5G & IoT – Modern networks and smart devices depend on semiconductor chips.
✔ Essential for Global Tech – Semiconductor shortages can disrupt entire industries.
Future of Semiconductors
✔ Graphene & 2D Materials – Next-gen semiconductors promise faster, energy-efficient devices.
✔ Quantum Computing – Semiconductor-based qubits are being explored for quantum processors.
✔ Flexible & Organic Semiconductors – Used in wearable technology and foldable screens.
Conclusion
Semiconductors revolutionized technology, powering modern computing, communication, and energy systems. As research advances, AI, quantum computing, and smart materials will push semiconductor technology even further.