Chapter 45-Semiconductors

Semiconductors are at the heart of electronics devices and things like mobiles which we use today. It’s a tough topic to understand but we have made it as simple as possible, with creative animations, 3D models and images.

Following topics are covered:

1) Why is it called ‘semi’ conductor?

2) gadgets having semiconductors

3) About Conductivity

4) Energy Bands in solids: Conduction band and Valence band

5) About Semiconductors: holes and electron movements

6) p-n junction

• Diffusion current
• Biasing a p-n junction : Forward and Reverse Bias

7) p-n junction Diode

8) p-n junction as a Rectifier

9) Transistors – comparing with the older Triodes

10) Transistors: a sandwitch of P-N-P and N-P-N

• N-P-N transistor: how it works
• Symbol and circuit diagram

11) P-N-P Transistor

• Symbol and circuit diagram

12) Transistor Symbols: Emitter and Colelctor positions – the easy way – for NPN and PNP

13) Biasing of Transistors, and Thermal runaway

• Beta dependent and beta-independent types of biasing

14) Solved problems