At room temperature, number of electrons in a pure Ge crystal is 1015 m -3. If 1021 In atoms are mixed per m 3 in the crystal then the number of electrons in the extrinsic semiconductor is :-

Question

At room temperature, number of electrons in a pure Ge crystal is 1015 m -3. If 1021 In atoms are mixed per m 3 in the crystal then the number of electrons in the extrinsic semiconductor is :- (A) 1021 m -3 (B) 1015 m -3 (C) 109 m -3 (D) 106 m -3

Tardigrade Admin · Accepted Answer

n i 2= n e × n n ⇒ (1015)2= n e × 1021 ⇒ n e =109 m -3

Q. At room temperature, number of electrons in a pure Ge crystal is $1 0^{15} m^{- 3}$ . If $1 0^{21}$ In atoms are mixed per $m^{3}$ in the crystal then the number of electrons in the extrinsic semiconductor is :-

$1 0^{21} m^{- 3}$

$1 0^{15} m^{- 3}$

$1 0^{9} m^{- 3}$

$1 0^{6} m^{- 3}$

$n_{i}^{2} = n_{e} \times n_{n}$
$\Rightarrow (1 0^{15})^{2} = n_{e} \times 1 0^{21}$
$\Rightarrow n_{e} = 1 0^{9} m^{- 3}$

Q. At room temperature, number of electrons in a pure Ge crystal is 1015m−3. If 1021 In atoms are mixed per m3 in the crystal then the number of electrons in the extrinsic semiconductor is :-

1021m−3

1015m−3

109m−3

106m−3