Question

If Phosphorous is doped with silicon and silicon is doped with Boron, identified the type of
semi conductions.

Answer 1

Outermost electron of Phosphorous is 5 and outermost electron of
silicon is 4. so phosphorous is doped with silicon, then 4 electrons
of phosphorous is bonded with four silicon, and one electron will be
left unbonded. So we will get free electrons, hence it will be
n-types.

Again silicon has 4 outermost electrons and boron has 3. If silicon is
doped with Boron, same way we get one extra electron per silicon
dopped atom, so it will be again n-types,