Physics Circle home Student Login

Home›Chapters›Semiconductor Electronics PYQs›Intrinsic & Extrinsic Semiconductors›Question 36

JEE Main 2021 (25 Jul, Shift 2) · Intrinsic & Extrinsic Semiconductors

Intrinsic & Extrinsic Semiconductors question from JEE Main 2021 (25 Jul, Shift 2)

Q36JEE Main 2021 · 25 JUL · SHIFT 2Easy

Intrinsic & Extrinsic Semiconductors

In a semiconductor, the number density of intrinsic charge carries at 27∘^\circC is 1.5 ×\times 1016/m3. If the semiconductor is doped with impurity atom, the hole density increases to 4.5 ×\times 1022/m3. The electron density in the doped semiconductor is ___________ ×\times 109/m3.

Numerical answer type. Work it out, then open the answer.

Show answer and solution

Answer: 5

  1. Mass action law: nenh=ni2n_e n_h = n_i^2
  2. ne=(1.5×1016)24.5×1022=2.25×10324.5×1022n_e = \dfrac{(1.5\times10^{16})^2}{4.5\times10^{22}} = \dfrac{2.25\times10^{32}}{4.5\times10^{22}}
  3. ne=5×109 /m3n_e = 5\times10^{9}\ /\text{m}^3
  4. So the answer is 5.
Report a mistake

More questions on Intrinsic & Extrinsic Semiconductors