Pure silicon at 300K has equal electron (ne) and hole (nh) concentration of 1.5× 1016m-3. Doping by indium increase (nh) to 4.5× 1022m-3. The (ne) in the doped silicon is

Question

Pure silicon at 300K has equal electron (ne) and hole (nh) concentration of 1.5× 1016m-3. Doping by indium increase (nh) to 4.5× 1022m-3. The (ne) in the doped silicon is (A)  9× 105  (B)  5× 109  (C)  2.25× 1011  (D)  3× 1019

Tardigrade Admin · Accepted Answer

nenh=(ni)2 ne× 4.5× 1022=(1.5× 1016)2 ne=(2.25× 1032/4.5× 1022) ne=5× 109

Q. Pure silicon at 300K has equal electron $(n_{e})$ and hole $(n_{h})$ concentration of $1.5 \times 10^{16} m^{- 3} .$ Doping by indium increase $(n_{h})$ to $4.5 \times 10^{22} m^{- 3} .$ The $(n_{e})$ in the doped silicon is

$9 \times 10^{5}$

$5 \times 10^{9}$

$2.25 \times 10^{11}$

$3 \times 10^{19}$

$n_{e} n_{h} = (n_{i})^{2}$ $n_{e} \times 4.5 \times 10^{22} = (1.5 \times 10^{16})^{2}$ $n_{e} = \frac{2.25 \times 10 ^{32}}{4.5 \times 10 ^{22}}$ $n_{e} = 5 \times 10^{9}$

Q. Pure silicon at 300K has equal electron (ne​) and hole (nh​) concentration of 1.5×1016m−3. Doping by indium increase (nh​) to 4.5×1022m−3. The (ne​) in the doped silicon is

9×105

5×109

2.25×1011

3×1019