Question

Non-stoichiometrice cuprous oxide, Cu2O can be prepared in the laboratory. In this oxide, copper to oxygen ratio is slightly less than 2:1. Can you account for the fact that this substance is p-type semiconductor.

Answer 1

The ratio is less than 2:1 in Cu2O shows that some cuprous(Cu+) ions have been replaced by cupric (Cu2+) ions. To maintain electrical neutrality, every two Cu+ ions will be replaced by one Cu2+ ion thereby creating a’ . As conduction will be due to presence of these positive , hence it is a p-type semiconductor.