Band Theory of Solids: Electron Conduction & Current

[Quotes]

Do electrons in conduction band are only responsible for current? Don't the electrons in partially filled valence band capable of moving contribute to current?
Material discussed-metals(conductors)

 

[ZapperZ]

Where is this partially-filled valence band in a metal?

Zz.

 

[Quotes]

Where is this partially-filled valence band in a metal?

Zz.

In metals either of the two cases exists-
1. Conduction band is partially filled and the valence band is partially empty. OR
2. Conduction and valence band overlap.

 

[ZapperZ]

In metals either of the two cases exists-
1. Conduction band is partially filled and the valence band is partially empty. OR
2. Conduction and valence band overlap.

Show me the band structure where the valence band is partially empty.

Zz.

 

[Quotes]

Show me the band structure where the valence band is partially empty.

Zz.

 

[ZapperZ]

This references are utterly confusing (what text are you using that has a typo of valence being replaced by "balanced"). The 2nd one, especially, is trying to differentiate between a metal and a semiconductor! We know about unfilled valence band for semiconductor. What I'm asking is for you to show me an example on the band structure of a metal that has a partially empty valence band.

I bet you that what is being described here is the difference between an insulating and a conducting state of a semiconductor! This is not a metal! A semiconductor may be conducting, but it is STILL not a metal! The valence band of a metal doesn't play a role in its charge transport properties. A semiconductor does!

I suggest you look very, VERY carefully at what you are reading and the terminology that you are using.

And please read this thread on why I consider the explanation of "band overlap" is flawed:

https://www.physicsforums.com/threads/how-does-band-structure-lead-to-metals-insulators.839172/

Zz.

 

[DrDu]

In semi-metals like Bismuth and graphite, you encounter the situation that there is one band almost filled and one band almost empty. Personally, I generally would avoid speaking of conduction and valence bands as this termini are clearly missleading.

 

[hokhani]

Do electrons in conduction band are only responsible for current? Don't the electrons in partially filled valence band capable of moving contribute to current?
Material discussed-metals(conductors)

The electrons in valence band move with their corresponding group velocities but they don't conduct any charge because they move in different directions. I think it is possible to have conduction by the electrons in partially filled valence band provided that the symmetry of distribution in the band is broken.

 

[DrDu]

If this were true, p-doped semiconductors would be isolators, too.