Question

Would there be any advantage to adding $n$-type or $p$-type impurities to copper:

• A. Yes
• B. No
• C. May be
• D. Information is insufficient

Answer 1

The correct option is B No

Pure $Cu$ is already an excellent conductor, since has a partially filled conduction band, furthermore, $Cu$ forms a metallic crystal as opposed to the covalent crystal of silicon or germanium, so the scheme of using an impurity to donate or accept an electron does not work for copper. In fact adding impurities to copper decrease the conductivity because an impurity tends to scatter electrons, impending the flow of current.