Question

Silicon doped with arsenic is

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

Answer 1

Answer: (B)

$n$-type semiconductor

Answer 2

When Si (having 4 valence electrons) is doped with As (having 5 valence electrons),4 electrons form covalent bonds while the fifth electron remains free and increase conductivity. Hence, Si doped with As is 11-type semiconductor.