Fermi energy above the conduction band minimum

[phonics]

Deal all,

I am studying the oxidation and hydration of the Ga-polar and N-polar surfaces of GaN.

the results for the oxidation and hydration of N-polar GaN are fine (band-gap opening of the metallic surface, work function, fermi level, etc)

however, for the Ga-polar system, I am getting a fermi energy that is well above the conduction band minimum (VBM = -1.8 eV, CBM= -0.4 eV, and Ef = 3.33 eV), I am wondering if this calculation is correct/physically meaningful ?

for each study the other side of the slab is passivated with pseudo-hydrogen.

Thank you for your help,