SEMICONDUCTOR

Semiconductors are materials like silicon and germanium that conduct electricity better than insulators but worse than conductors. Pure semiconductors aren't very useful, so we add impurities through doping to make them practical. Adding elements with extra electrons creates n-type (negative) semiconductors, while adding elements with missing electrons creates p-type (positive) semiconductors.

When you join p-type and n-type materials together, you create a diode—a device that allows current to flow in one direction only. Think of it like a one-way valve in a water pipe. Diodes are everywhere in Nigeria: your phone chargers use diodes to convert AC to DC power. When forward biased (positive to p-side), diodes conduct easily. When reverse biased, they block current.

Transistors are three-terminal devices built from semiconductor materials that amplify signals or switch circuits on and off. They're the building blocks of modern electronics.