I Fermi level change in semiconductors

[Helena Wells]

TL;DR Summary

Does the acceptor level or donor level change if we change the base of the semiconductor?

Suppose we have a crystal lattice of doped Si with dopant Boron atoms. The energy level of the holes of the Boron atoms are just some eV above the valence band of Si.

My question: If we replace all the Si atoms with Ge atoms will the acceptor level change or not? I don't think it will change but why not ask it? In other words, does the acceptor level depend on the type of semiconductor we use as base?

 

[hutchphd]

The band structure is a product of the crystal structure (which reflects the structure of the base) as well as the interatomic spacing. The band gap for Silicon is twice that of Germanium and so yes it does depend. I believe the most important effect is the interatomic distance, but don't quote me..

 

[Helena Wells]

So will it be higher or lower?Is there a general rule for it?

 

[Helena Wells]

The band structure is a product of the crystal structure (which reflects the structure of the base) as well as the interatomic spacing. The band gap for Silicon is twice that of Germanium and so yes it does depend. I believe the most important effect is the interatomic distance, but don't quote me..

@hutchphd what are you studying/have you studied?

 

[hutchphd]

Long ago I did solid state theory...mostly surfaces and scattering from surfaces. I am now retired after doing optical, electronic, and systems design mostly for medical devices for 25 years . Also folks would occasionally hire me just for another novel look at a problem. I am a better engineer than I am a physicist...but I do love knowing the physics.

 

[Useful nucleus]

So will it be higher or lower?Is there a general rule for it?

I do not believe there is a general rule of thumb. Especially in complex compund semiconductors (like oxides and nitrides).
However in 2003, it was shown that hydrogen has a universal energy level provided that the band gap of the semiconductor is aligned according to unified scale (for example aligned with respect to vacuum level).

This is the paper that pointed this out:
https://www.nature.com/articles/nature01665