Question

A semiconductor has an electron concentration of $8\times 10^{13} / \mathrm{m}^{3}$ and hole concentration of $5.5\times 10^{12} / \mathrm{m}^{3}$. The semiconductor is

• A. $n$-type
• B. $p$-type
• C. intrinsic semiconductor
• D. $p$-$n$ junction

Hint:

In $n$-type semiconductor, electrons are majority carriers.

Answer 1

The Correct Option is A

To determine the type of semiconductor, we need to compare the electron concentration and hole concentration:

• Electron concentration, \(n_e = 8 \times 10^{13} \, \text{m}^{-3}\)
• Hole concentration, \(p_h = 5.5 \times 10^{12} \, \text{m}^{-3}\)

Semiconductors can be categorized based on the majority charge carriers:

• n-type semiconductor: The electron concentration is greater than the hole concentration.
• p-type semiconductor: The hole concentration is greater than the electron concentration.
• Intrinsic semiconductor: The electron and hole concentrations are equal.

In this case, the electron concentration \((8 \times 10^{13} \, \text{m}^{-3})\) is significantly greater than the hole concentration \((5.5 \times 10^{12} \, \text{m}^{-3})\). Thus, the majority charge carriers are electrons.

Therefore, the semiconductor is an n-type semiconductor.