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

Since it is given that the ratio of Cu2+ ions is lesser as compared to the ratio of Oxide ions, that means, certain sites where actually there should be the presence of copper ions (i.e, positive ions) are now vacant.
Thus, one can say that it has a larger hole concentration than electron concentration. The phrase 'p-type' refers to the positive charge of the hole. In p-type semiconductors, holes are the majority carriers and electrons are the minority carriers.
Thus, Cu20 can act as a p type semiconductor.

Dear Student,
Please find below the solution to your problem.

Since it is given that the ratio of Cu2+ ions is lesser as compared to the ratio of Oxide ions, that means, certain sites where actually there should be the presence of copper ions (i.e, positive ions) are now vacant.
Thus, one can say that it has a larger hole concentration than electron concentration.
The phrase 'p-type' refers to the positive charge of the hole. In p-type semiconductors, holes are the majority carriers and electrons are the minority carriers. Thus,
Cu20 can act as a p type semiconductor.

Thanks and Regards