Can anyone let me know whether is there any method/technique to find the Fermi level position (from conduction band or vacuum level) of a semiconductor (eg. CdS, CdTe) or a heterojunction (eg. Cd/CdTe) using any characterization technique? It will be helpful to design a graded bandgap material with perfect Fermi level alignment. I heard it might be possible with XPS, but no idea about how to do it.
Thank you.