When silicon is doped with 2×10^19 cm^-3 boron atoms, the resulting semiconductor is best described as:

B) Lightly doped n‑type semiconductor

D) Intrinsic semiconductor with compensation

When silicon is doped with $2 \times 1 0^{19} cm^{- 3}$ boron atoms, the resulting semiconductor is best described as:

medium MCQ 2 marks Class 12 · Physics · Semiconductor Electronics Materials Devices and Simple Circuits

Answer

C) Heavily doped p‑type (degenerate)

The correct answer is C) Heavily doped p‑type (degenerate) — The correct choice is option C.

Identify the dopant: boron creates acceptor levels, so the material is p‑type.
Compare the dopant concentration with the typical intrinsic carrier concentration of silicon ( $\sim 1 0^{10} cm^{- 3}$ ). The given concentration is $1 0^{19} cm^{- 3}$ , i.e., many orders higher, indicating heavy (degenerate) doping.
Select the option that matches a heavily doped p‑type semiconductor.
The correct choice is option C.

Common mistake: Confusing heavy p‑type doping with lightly doped n‑type material.

Concept tested: Doping classification