Question

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

Answer 1

Hey there!

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Answer -:

$CU_{2}O$ has copper to oxygen ratio which is slightly less than 2 : 1. Since +ve charge is less than negative charge, therefore, positive ion will move resulting in formation of ρ-type semiconductor.

Answer 2

When cuprous oxide is prepared in laboratory, the ratio of copper to the oxygen in the compound becomes slightly less that 2:1.

This happens because some of the $\bf{Cu^+}$ ions are replaced by $\bf{Cu^{2+}}$  ions. In this process, one $\bf{Cu^{2+}}$ ion is replaced by two $\bf{Cu^+}$ ions. As two $\bf{Cu^+}$ ions are replaced by one $\bf{Cu^{2+}}$, this creates a defect because of vacant space, i.e. $\bf{positive\:hole}$. Because of the creation of holes due to this defect, this compound conducts electricity through these positive holes. As semiconductors which are formed by electron deficient impurities are called the p – type semiconductors; thus cuprous oxides so formed in laboratory are $\bf{p- type}$ semiconductors.