Potential Barrier for different types of junctions

[Joseph8022]

Hi all,
How I can calculate the Potential Barrier when we have a metal- semiconductor, metal- metal, or p-n junction ? Can I calculate the Potential Barrier by using a workfuncion?

 

[Simon Bridge]

Welcome to PF;
The exact shape of the barrier is usually modeled using self-consistent calculations - depending on the exact structures being modeled.

The height of the barrier can sometimes be worked out from the band-mismatch.

 

[Joseph8022]

Welcome to PF;
The exact shape of the barrier is usually modeled using self-consistent calculations - depending on the exact structures being modeled.

The height of the barrier can sometimes be worked out from the band-mismatch.

Thank you! I have a lot of formulas for calculating the Potential Barrier, and I get confused with them. I'm not sure about it ! In p-n junction, can I find the Potential Barrier by finding the difference in Fermi energy of the p and n-type junction? What about if I have a metal-semiconductor junction ?

 

[Simon Bridge]

You should be able to make out what your formulas are about by sketching the band profiles next to each other.
At the junction you'd get some band bending irl.

 

[Joseph8022]

You should be able to make out what your formulas are about by sketching the band profiles next to each other.
At the junction you'd get some band bending irl.

Thank you, again ! I need to know the formula for calculating the Potential Barrier in p-n junction, please, write it down if you know it.

 

[Simon Bridge]

In general?

It's a self-consistent calculation using Poisson's equation to work out the band bending and the Schrödinger equation to work out the charge distribution. Rinse and repeat. What level education are you doing this at? Did you have a specific p-n junction in mind?