Why is called n-type and p-type semiconductor? What is behind the choice of n and p as letters to represent the 2 different types of semiconductors?

This is a naming question, not so much about electrical engineering.

I keep forgetting/mixing up which is the n-type and which is the p-type semiconductor.

Usually the names act like mnemonic devices for us to more easily recall which object is associated with which label/word.

What does the n stand for?

What does the p stand for?

For example, I would name it h-type form hole-type instead of p-type to remove the confusion. But I'm assuming there is already a connection like this behind the use of p and n letters - i just don't know it.

Are this just arbitrary names/letters? (doesn't make much sense to be arbitrary)

What keeps you personally from mixing the 2.

• negative/positive. Jun 11, 2019 at 18:13
• @Eugene Sh. oh crap, this must be the dumbest question ever :))
– AIon
Jun 11, 2019 at 18:15
• For bipolar transistors, NPN = Not Pointing iN (the arrow on the emitter points away from the base, out of the symbol), PNP = Pointing iN (arrow points towards the base, into the symbol) Jun 11, 2019 at 19:51
• Nah, just an honest question with an easy answer! I've always been fond of this question, and am glad the user didn't remove it :) Jun 12, 2019 at 6:38
• PNP = pointing in proudly Oct 12, 2019 at 6:15