Semiconductors

Question 1

Difference between N-type and P-type material

What’s important to remember about the charges of these

Answer 1

N-type: doped with material with one extra electron
Has one to spare

P-type: doped with material with one less electron
Has an extra “hole” to take an electron

Neutral charged - not actually negative or positive

Question 2

Whats the region between an n-type and a p-type called

What happens when they touch

Answer 2

Depletion zone

Electrons flow from N-type into P-type in area until zone has neutral charge

Question 3

How does a diode work (reference to n-type and p-type materials)

Answer 3

N-type connected to p-type.
To get electrons moving, connect n-type to negative side of circuit and vice versa for p-type
When voltage is high enough, electrons in depletion zone are boosted out of their holes and move freely again

Question 4

Names of pins on a transistor and how to figure it out

Answer 4

Base is always middle pin
Emitter always connects to base via arrow

In NPN transistor, base = high, if current flows from base to emitter collector -> emitter

In PNP transistor, base = low, if current flows from emitter to base
emitter -> collector