Consider excitations from level εi = -4 eV with 1025 states/m3 to level ε j = -2.5 eV with 1024 states/m3 in a semiconductor at 295 K. (Treat the states as band-edge equivalent states if you wish.)
(a) How many excitations are there per cubic meter?
(b) What is the energy of the Fermi level?
(c) Repeat for the same case except that level i now has 1026 states/m3 and the temperature is 500 K.