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Electric field needed to excite electrons to conduction band

  1. Jun 9, 2015 #1
    What's the electric field strength needed to get one of lithium's core electrons into the conduction band? How do you figure this out?
     
  2. jcsd
  3. Jun 9, 2015 #2

    blue_leaf77

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    First of all I have never heard people talking about energy band in a single atom, bands of energy are formed when many atoms or molecules are bound together forming what we know as solid. And be it energy bands or well separated individual energy levels, what determines, among others, whether an excitation is likely to take place or not is the photon energy, the probability of which is higher for photon energies closer to the energz difference between levels or bands in question. Increasing electric field strength only increases the probability of multiphoton excitation for photon energies lower than the resonance one-photon energy.
     
    Last edited: Jun 9, 2015
  4. Jun 9, 2015 #3

    ZapperZ

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    Assuming that you are talking about solid lithium metal, then you need to figure out the binding energy corresponding to that core level. Find a good XPS data on it.

    Zz.
     
  5. Jun 9, 2015 #4
    I was just thinking of a lithium wire in a strong electric field (a field surrounding the wire, not just the field along the axis of the wire to get current) and how strong of an electric field you would need to excite a core electron into becoming a conduction electron.
     
  6. Jun 9, 2015 #5

    blue_leaf77

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    One has to know the energy difference between the mentioned bands.
     
  7. Jun 9, 2015 #6

    ZapperZ

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    While to some extent, one can induce the Stark Effect in these things, I don't believe that you can do such excitation using simply a "strong electric field". This is because, in the practical sense, you might induce a breakdown on the surface of the conductor first before you can achieve the E-field necessary. I say this because at ~60 MV/m, conductors such as Cu already will experience vacuum breakdown. All this before you actually see any kind of indication that at fields below this, such core-level excitation have occurred. This means that it will require substantially higher E-field than this. So you will induce a breakdown on the surface first before anything else.

    Zz.
     
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