In sample of pure silicon 1013 atom / cm 3 is mixed of phosphorus. If all donor atoms are active then what will be resistivity at 20° C if mobility of electron is 1200 cm 2 / volt-s :-

Question

In sample of pure silicon 1013 atom / cm 3 is mixed of phosphorus. If all donor atoms are active then what will be resistivity at 20° C if mobility of electron is 1200 cm 2 / volt-s :- (A) 0.5209 ohm cm (B) 5.209 ohm cm (C) 52.09 ohm cm (D) 520.9 ohm cm

Tardigrade Admin · Accepted Answer

No. of free e-=Impurity donor concentration σ=μe n e e=μe N D e and ρ=(1/σ)=(1/μe N D e) ρ=(1/1200 × 1013 × 1.6 × 10-19)=520.9 ohm cm

Q. In sample of pure silicon $1 0^{13} a t o m / c m^{3}$ is mixed of phosphorus. If all donor atoms are active then what will be resistivity at $2 0^{\circ} C$ if mobility of electron is $1200 c m^{2} /$ volt-s :-

0.5209 ohm cm

5.209 ohm cm

52.09 ohm cm

520.9 ohm cm

No. of free $e^{-} =$ Impurity donor concentration
$σ = μ_{e} n_{e} e = μ_{e} N_{D} e$
and $ρ = \frac{1}{σ} = \frac{1}{μ _{e} N _{D} e}$
$ρ = \frac{1}{1200 \times 1 0 ^{13} \times 1.6 \times 1 0 ^{- 19}} = 520.9$ ohm cm

Q. In sample of pure silicon 1013atom/cm3 is mixed of phosphorus. If all donor atoms are active then what will be resistivity at 20∘C if mobility of electron is 1200cm2/ volt-s :-