Semiconductors and Diodes
Semiconductors conduct electricity better than insulators but worse than metals, and a diode uses them to let current flow in one direction.
▶ Interact
Play with the controls to see the idea in action.
📘 Learn
Semiconductors conduct electricity better than insulators but worse than metals, and a diode uses them to let current flow in one direction.
- Silicon is a common semiconductor
- LEDs are diodes that emit light
- Diodes are used to convert AC to DC
🧠 Quick quiz
Three questions. Score 2 or more to complete the topic.
What is Semiconductors and Diodes?
Within Physics, which covers forces, energy, waves, electricity, magnetism, light and space explained through motion and experiments, this topic explains Semiconductors and Diodes. Physics topics explain how things move, push, heat up and carry energy, so each one here pairs a definition with a live model you can change.
Check that you can explain Semiconductors and Diodes in your own words and give one example from everyday life. If you can do that, you have understood the core idea.
Understanding Semiconductors and Diodes explains how the physical world behaves, from sport and transport to electricity and medicine.
Semiconductors and Diodes in detail
Semiconductors, such as silicon and germanium, conduct better than insulators but worse than metals, and their conductivity can be controlled by doping with other atoms. N-type material has extra electrons, while p-type material has missing electrons, called holes.
A diode joins p and n material in a p-n junction and allows current in only one direction (forward bias). Used in rectifiers, diodes convert AC to DC. LEDs emit light when forward biased, and solar cells use the junction to convert light to electricity. Semiconductors are the basis of transistors and all modern electronics.
How the interactive helps you understand Semiconductors and Diodes
Watch the circuit in the interactive. Use any sliders or buttons it offers to change the values and see how the circuit responds.
Before you change anything, predict the result. Then change one value at a time and check whether your prediction was right. This is a quick way to build a correct mental model of Semiconductors and Diodes.
Real-life uses and examples
- Explain everyday devices, such as brakes, lifts or chargers, using Semiconductors and Diodes.
- Use Semiconductors and Diodes to make sense of a practical and its results.
- Answer “explain” questions by linking Semiconductors and Diodes to a clear cause and effect.
Common mistakes to avoid
- Forgetting that some quantities, such as force or velocity, also have a direction.
- Mixing up Semiconductors and Diodes with a related quantity that has different units.
- Learning the definition without testing it. Use the quiz and the interactive to check that you can apply the idea.
Frequently asked questions about Semiconductors and Diodes
What is Semiconductors and Diodes?
Semiconductors conduct electricity better than insulators but worse than metals, and a diode uses them to let current flow in one direction.
What are the most important points about Semiconductors and Diodes?
The main points are: Silicon is a common semiconductor; LEDs are diodes that emit light; Diodes are used to convert AC to DC.
Why is Semiconductors and Diodes useful?
Understanding Semiconductors and Diodes explains how the physical world behaves, from sport and transport to electricity and medicine.
How can I practise Semiconductors and Diodes?
Open the interactive at the top of this page and change the controls one at a time. Predict the result before each change, then take the three-question quiz. A score of two or more marks the topic as complete on this device.
Which topics are related to Semiconductors and Diodes?
Related topics in Physics include Renewable Energy: Solar and Wind, Graphs in Physics, Scalars and Vectors.