Question

Let $n_p$ and $n_e$ be the numbers of holes and conduction electrons in an extrinsic semiconductor.

• A. $n_p > n_e$
• B. $n_p = n_e$
• C. $n_p < n_e$
• D. $n_p \neq n_e$

Answer 1

Answer: (D)

(4)

Answer 2

An extrinsic semiconductor is doped to have either excess electrons (n-type) or excess holes (p-type). In an n-type semiconductor, $n_e > n_p$. In a p-type semiconductor, $n_p > n_e$. Therefore, in any extrinsic semiconductor, the number of holes ($n_p$) and conduction electrons ($n_e$) are not equal, i.e., $n_p \neq n_e$.