Verified Solution • 2025–26 Session moderate

QJEEM21Ph48a1: JEE Main 2021 Physics - Class 12 JEEM21Ph48a1 Solution: In a semiconductor, the number density of intrinsic charge…

In a semiconductor, the number density of intrinsic charge carries at 27 ∘^\circ C 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.

Step-by-Step Verified Solution

nenh=ni2{n_e}{n_h} = {n_i}^2

ne=ni2nh=(1.5×1016)24.5×1022{n_e} = {{{n_i}^2} \over {{n_h}}} = {{{{(1.5 \times {{10}^{16}})}^2}} \over {4.5 \times {{10}^{22}}}}

=1.5×1.5×10324.5×1022= {{1.5 \times 1.5 \times {{10}^{32}}} \over {4.5 \times {{10}^{22}}}}

=5×109= 5 \times {10^9} /m3

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