Semiconductor
Semiconductor
A material whose conductivity falls between a conductor and an insulator, allowing electrical flow to be controlled.
In Simple Terms
A semiconductor is a material or component whose electrical conductivity changes depending on the conditions. It shows up in CPUs and memory in smartphones and computers, plus everyday appliances and cars — basically every electronic device around you. By controlling the flow of electricity with incredible precision, it handles complex calculations and stores data.
Behind the Name
The name comes from "semi-", meaning "half" or "partial" — a nod to how the material sits between a "conductor", which carries electricity easily, and an "insulator", which barely carries it at all. Its conductivity can be controlled depending on the conditions, landing it right in the middle.
Take a Closer Look!
A semiconductor is a material with conductivity between a "conductor" (like metal) and an "insulator", which barely conducts electricity.
Mixing a tiny amount of impurities into silicon crystal makes it easier for electricity to flow, producing two types of material: "n-type", where negative electrons carry the current, and "p-type", where positive "holes" do.
Put simply, a component made from semiconductors called a "transistor" works like a tiny switch.
The transistor mainly used in computers, called a "MOSFET", combines n-type and p-type material with an electrode called a "gate". Switching the voltage precisely controls whether electricity flows or stops.
Combining billions of these transistors on one chip enables complex calculations, and pairing them with charge-storing structures enables data storage.
The CPU — the brain of a computer or smartphone — uses countless transistors as switches to process instructions.
Working memory uses transistors as switches to store charge in capacitors, holding data based on whether charge is present. Since charge naturally leaks away, it needs constant "refreshing", and everything is lost when the power turns off.
Flash memory, used in SSDs and similar devices, traps electrons inside a structure so data survives even after power is cut.
Image sensors use the fact that light converts to electricity, turning a scene into electrical signals.
In these ways, semiconductors form the core of countless electronic devices — from everyday appliances and cars to large-scale machinery.