In an intrinsic semiconductor the energy gap `E_(g) is 1.2 eV`. Its hole mobility is much smaller than electron mobility and independent of temperature. What is the ratio between conductivity at `600K` and `300K`? Assume that temperature dependence intristic concentration `n_(i)` is given by `n_(i)=n_(0) exp ((-E_(g))/(2k_T))`, where `n_(0)` is a constant and `k_=8.62xx10^(-5)eV//K`.

In an intrinsic semiconductor the energy gap `E_(g) is 1.2 eV`. Its ho

1.	In an intrinsic semiconductor the energy gap `E_(g) is 1.2 eV`. Its hole mobility is much smaller than electron mobility and independent of temperature. What is the ratio between conductivity at `600K` and `300K`? Assume that temperature dependence intristic concentration `n_(i)` is given by `n_(i)=n_(0) exp ((-E_(g))/(2k_T))`, where `n_(0)` is a constant and `k_=8.62xx10^(-5)eV//K`.
Answer» Here, `E_(g)/(2k)[1/T_(1)-1/T_(2)]=1.2/(2xx8.62xx10^(-5))[1/300-1/600]=11.6` `n_(600)/n_(300)=e^(E_(g)/(2k)[1/T_(1)-1/T_(2)])=e^(11.6)=(2.718)^(11.6)=1.089xx10^(5)=1.1xx10^(5)` `sigma_(600)/sigma_(300)=n_(600)/n_(300)=1.1xx10^(5)`