mixing 2nd and 6th groups' elements to semiconductor silicon

[PainterGuy]

Hi everyone, :smile:

I was wondering why they only use 5th and 3rd groups elements to create n-type and p-type semiconductors respectively. Couldn't we mix 6th or 2nd groups' elements instead to make the semiconductors? What would happen if we do this? Perhaps elements of those groups will bind to the silicon or germanium atoms too strongly and there would not be free charges then. Many thanks for any help you can offer.

Cheers

[Jiggy-Ninja]

Chemistry's not my strong point (I prefer physics), but I know one for sure.

6th group elements would be more likely to form double covalent bonds rather than n-type silicon. An example, carbon dioxide. Carbon (4th period) bonds with two oxygen (6th period) with a pair of double covalent bonds to form CO2.

For 2nd period chemicals...ionic bonds, I think? Not too sure about that one.

[MATLABdude]

My off the-cuff semi-educated guess would be that this is undesirable due to the fact that you'd end up with two charged states for acceptors and/or donors, +/-2, and +/-1. This probably has some sort of impact on how how smoothly, and how quickly logic level transitions occur (when making transistors).

Since semiconductor physics was a long time ago for me (and I don't have my textbook on my shelf), I've asked for this to be moved to the appropriate forum, and a mod may be by to do so.

EDIT: Unless someone remembers their semiconductor physics better than I do.