1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

What's a good primer of band theory (metals and semiconductors).

  1. Feb 8, 2014 #1
    Re: How do you calculate the location of the third virtual image?

    Edit: I've made some progress on this one, and I now understand that the valence and conductance bands are composed of molecular orbitals contributed by each metallic atom joining the molecule.

    For example, three lithium atoms would contribute three total molecular orbitals, resulting in three bands. The bottom two might be the valence bands and hold all the elections, while the third might be the conductance band.

    Here's the question:

    Why does that third band (the conductance band) have a higher energy level than the valence bands, especially if they were all the same type of orbital (2s) contributed by lithium atoms?
     
    Last edited: Feb 8, 2014
  2. jcsd
  3. Feb 12, 2014 #2

    DrClaude

    User Avatar

    Staff: Mentor

    All orbitals of the same type will contribute the the same band. In the case of lithium, the 2s orbitals will make up the s-band. Since each lithium atom contributes only one electron to the s-band, it is half-filled and electrons can move from one atom to the next, so it is a conduction band.

    If the s-band was completely filled, then it would become a valence band, and the higher energy p orbitals would form the p-band, which would be the conduction band, and there would be a band gap between the two, due to the difference in energy between s and p orbitals.
     
  4. Feb 14, 2014 #3
    Oh. That's a great explanation. Why didn't they put *that* in the textbooks?
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: What's a good primer of band theory (metals and semiconductors).
  1. Band Theory (Replies: 1)

Loading...