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

Is there any benefit to adding trivalent or pentavalent impurity to the copper ?

Donor type impurity is found in

To obtain n-type semiconductor , the impurity introduced is

p-type and n-type semiconductors .

Draw a labelled ray diagram of a reflecting type telescope. Write its any one advantage over refracting type telescope.

What type of impurity is added to obtain N-Type and P-Type semi conductors ?