Final answer:
An n-type semiconductor is produced by adding impurity atoms with one more valence electron to a pure semiconductor material.
Step-by-step explanation:
An n-type semiconductor material is produced by adding impurity atoms to a pure semiconductor material.
When impurity atoms are added to a semiconductor the net charge on the semiconductor material remains neutral. This is because each impurity atom donate an electron to the conduction band but also introduces a positive charge due to the presence of the ionized impurity atom.