Materials whose electrical conductivity lies between that of conductors and insulators and can be controlled, making them the basis of modern electronics.
- Common semiconductors are silicon and germanium; their conductivity rises with temperature and with added impurities, unlike metals.
- Doping adds small amounts of impurity: n-type (extra electrons, from elements like phosphorus) and p-type (electron "holes", from elements like boron).
- A p-n junction is the basic building block; it forms diodes (one-way current), transistors (switching and amplification), and integrated circuits (chips).
- Semiconductors power computers, mobile phones, solar cells, and LEDs; a chip packs billions of transistors.
- Strategically, chip manufacturing is concentrated in a few economies; India's Semiconductor Mission and incentive schemes aim to build domestic fabrication, a key current-affairs theme (verify the latest).
Semiconductors, silicon, doping, diodes and transistors are everyday-physics and information-technology facts, and chip self-reliance is a live national-security and economy topic.
Semiconductors are between conductors and insulators; their conductivity increases with temperature (opposite to metals). N-type carries current by electrons, p-type by holes.
Materials like silicon, controllable by doping, that form diodes, transistors, and chips, the base of all modern electronics.