Question

Question #de35e

Answer 1

To make a `p-`type semiconductor, you dope with an element such as boron that has three valence electrons.

Explanation:

Adding boron atoms in place of some of the germanium results in a crystal with some lattice sites having only three valence electrons rather than the four that Ge possesses. This is (somewhat misleadingly) called a "hole", as one orbital will be "missing" an electron as compared to a pure Ge crystal.

Being sort of the opposite of an electron, the hole is considered a positive charge carrier, as electrons which drift from an adjacent Ge atom into a hole will appear as if the hole were moving in the direction opposite to the electron drift.