Show that a semiconductor has a minimum conductivity at a given temperature where µ h µe n e = n i and n h = n i . µe

µh

Find the intrinsic and minimum conductivities for germanium at a temperature such that n i = 2.5 ×10 19 m − 3 , µ e = 0.38 m 2 / V .s, µ h = 0.19 m 2 / V .s . For what other values of n e and nh other than n e = n h = n i does this crystal have a conductivity equal to the intrinsic conductivity?