Calculating Fermi Level position in doped Silicon

Benjammith

Estimate the Fermi level position E_Fn for a Si sample at room temperature that
is doped with 10¹⁵ shallow donors cm^-3.




From coursework I've gatherred over the year I understand the equation needed is: E_F=E_C-kT ln(N_C/n)
n, being equal to the donor concentration
E_C is the conduction band energy.



my problem with the question is knowing the value of E_C. I know the value of the bandgap for silicon but I can't relate it to E_C without introducing E_V, another variable I don't know. Any help with finding E_C or another approach to the question would be great.

Zuma

If you assume Ec=0 eV... then the Fermi level will be reference to the conduction band edge (Ev would then be -Eg, since Eg = Ec - Ev).