Browse Questions

What is the resistivity of n-type semiconductors given: Density of conducting electrons $=8 \times 10^{13} /cc$; Density of holes $=5 \times 10^{12} /cc$ mobility of electron $=2.3 \times 10^4 cm^2 /v-s$ mobility of holes $=100 cm^2 /v-s$

$(a)\;0.12 \Omega\;m \\ (b)\;1.23 \Omega\; m \\ (c)\;0.34 \Omega\; m \\ (d)\;0.034 \Omega \;m$

Conductivity of semiconductors is
$\sigma = e( n_e \mu_e + n _h \mu _h)$
$\quad= (1.6 \times 10^{19} )( 8 \times 10^{19} \times 2.3 + 5 \times 10^{18} \times 10^{-2})$
$\quad =29.4 \;cm/v-s$
Resistivity $=\large\frac{1}{\sigma}=\frac{1}{29.4}$
$\qquad= 0.034 \Omega m$
Hence d is the correct answer.