How is a sample of n type semiconductor electrically neutral
Answers
Answer:
Due to doping by pentavalent elements of group 15 like phosphorous, n type semiconductors are electrically neutral.
Explanation:
The n type semiconductors of say, Germanium (Ge) when doped with pentavalent Phosphorous(P), it becomes electron rich. The four electrons of phosphorous form covalent bonds with four neighbouring Germanium element. But the fifth valence electron of the phosphorous element remains in the forbidden zone, which can move freely and somewhat makes the metal electron rich.
But this fifth electron is donated by the dopant atom i. E. Phosphorous and it itself becomes a positively charged ion. Thus the the number of electrons donated and the number of positive charge formed are equal and the semiconductor remains neutral.