Question

The conductivity of germanium at 20°C is 2/ohm m. What is its conductivity at 40°C? Eg=0.72eV

(a) 1.38×10^-23/Ohm m

(b) 1.0002/Ohm m

(c) 293/Ohm m

(d) 313/Ohm m

I got this question by my college director while I was bunking the class.

My query is from Properties of Semiconductors in division Semiconductors of Engineering Physics II

Answer 1

The correct option is (b) 1.0002/Ohm m

The explanation is: σ = Ce^(-E/2KT)

σ1/σ2  = e^(-E/2KT)/e^(-E/2KT)

σ2 = 1.0002/ Ohm m.