# Potential energy vs. fermi level in metal-metal junction under applied field

1. Apr 2, 2010

### SiO2

Hello,

I have been lurking in the forum for a while. I have couple of questions that I cannot really find an answer to yet. If any of you have idea/suggestion/know of where to look at, I would greatly appreciate.

First question:
Let's put two different work function metal blocks to each other such that they are ohmically contacted. Would you expect the work function of each block in contact configuration to be the same as two separate blocks (pre-contact)? I cannot find a paper on this... Well, if you have a paper on experiment such as work function on either side, that would be even better! I would imagine when they are in contact, charge transfer will occur to equilibrate the fermi level, and hence I would expect one metal to lose electron, another to gain such that the work function would be the same on both sides. In the process, the work function in the contact configuration would be different due to charge transfer.

Second question:
Hypothetically, let's consider a two metal junctions (three metal pieces). Pin the potentials of the left metal and the right metal such that the difference is $$\phi$$ (visually, you are applying $$\phi$$ to a metal.) So my understanding is you would expect no electrical potential gradient inside metal? If so, would you expect flat fermi level inside, or gradient fermi level?

I have attached picture in case my post is too wordy (it probably is...)

Thanks (and sorry for stupid questions)!
-SiO2

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