What is the conductivity of a semiconductor sample having electron concentration of $5 imes 10^{18

Question

What is the conductivity of a semiconductor sample having electron concentration of $5 	imes 10^{18} \mathrm{~m}^{-3}$, hole concentration of $5 	imes 10^{19} \mathrm{~m}^{-3}$, electron mobility of $2.0 \mathrm{~m}^2 \mathrm{~V}^{-1} \mathrm{~s}^{-1}$ and hole mobility of $0.01 \mathrm{~m}^2 \mathrm{~V}^{-1} \mathrm{~s}^{-1}$ ? (Take charge of electron as $1.6 	imes 10^{-19} \mathrm{C}$ )

Professor PC Thomas Classes · Answer

(b) : Given; $n_e=5 	imes 10^{18} \mathrm{~m}^{-3}, n_h=5 	imes 10^{19} \mathrm{~m}^{-3}$, $ \  \mu_e=2 \mathrm{~m}^2 \mathrm{~V}^{-1} \mathrm{~s}^{-1}, \mu_h=0.01 \mathrm{~m}^2 \mathrm{~V}^{-1} \mathrm{~s}^{-1} $ \  Then conductivity, $\sigma=e\left(n_e \mu_e+n_h \mu_hight)$.
Putting values, we get \ $\sigma=1.6 	imes 10^{-19}\left(5 	imes 10^{18} 	imes 2+5 	imes 10^{19} 	imes 0.01ight)$\ $=1.6 	imes 10^{-19}\left(10^{19}+0.05 	imes 10^{19}ight)=1.68(\Omega-\mathrm{m})^{-1}$