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Homework Help: Temperature effect on fermi level

  1. Dec 14, 2008 #1
    if fermi level is defined for 0K, then how does it vary in a semiconductor with temperature.
    also, why will the formation of holes affect the position of fermi level(by introducing acceptors). have i misunderstood something? please clear my doubt.
     
  2. jcsd
  3. Dec 15, 2008 #2

    Defennder

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    Extrinsic or intrinsic semiconductor?
    Suppose you dope the sample with acceptor atoms and these are ionised at room temperature. So what happens in the band diagram? You start to see more holes at the valence band due to electrons being excited fom Ev to Ea (where Ea is the energy level of the ionised acceptor ions). So what does that tell you about where you are most likely to find a half-filled energy level? Would it still be at Eg?
     
  4. Dec 15, 2008 #3
    thanks. i've realised that fermi level is the probability of occupancy of energy states. initially i thought it was the probability of occupancy of electrons. that is why i could'nt understand the role of holes in the shift in position of fermi level.
    and for that first question, i meant extrinsic.but now i understand. thanx.
     
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