Question

Band gap of Si depends on the temperature as E_g = 1.17 4.73*10^-4(T²/T+636) Find a concentration of electrons in the conduction band of intrinsic (undoped) Si at T = 77 K if at 300 K n_i = 1..05*10¹⁰cm^-3

Answer 1

Band gap of Si depends on the temperature as

Thus , E_g at 77 K : 1.169572 eV

E_g at 300 K : 1.169530 eV

Now,

And

Putting the proper values in the formula we obtain that

(approximately)