In a semiconductor, the number density of intrinsic charge carriers at 27° C is 1.5 × 1016 / m 3. If the semiconductor is doped with impurity atom, the hole density increases to 4.5 × 1022 / m 3. The electron density in the doped semiconductor is × 109 / m 3

Question

In a semiconductor, the number density of intrinsic charge carriers at 27° C is 1.5 × 1016 / m 3. If the semiconductor is doped with impurity atom, the hole density increases to 4.5 × 1022 / m 3. The electron density in the doped semiconductor is × 109 / m 3 (A)  (B)  (C)  (D)

Tardigrade Admin · Accepted Answer

ne nh=ni2 ne=(ni2/nh)=((1.5 × 1016)2/4.5 × 1022) =(1.5 × 1.5 × 1032/4.5 × 1022) 5 × 109 / m3

Q. In a semiconductor, the number density of intrinsic charge carriers at 27∘C is 1.5×1016/m3. If the semiconductor is doped with impurity atom, the hole density increases to 4.5×1022/m3. The electron density in the doped semiconductor is______ ×109/m3

ne​nh​=ni2​ ne​=nh​ni2​​=4.5×1022(1.5×1016)2​ =4.5×10221.5×1.5×1032​ 5×109/m3

$n_{e} n_{h} = n_{i}^{2}$
$n_{e} = \frac{n _{i}^{2}}{n _{h}} = \frac{( 1.5 \times 1 0 ^{16} ) ^{2}}{4.5 \times 1 0 ^{22}}$
$= \frac{1.5 \times 1.5 \times 1 0 ^{32}}{4.5 \times 1 0 ^{22}}$
$5 \times 1 0^{9} / m^{3}$