Valence band Definition and 25 Threads

In solid-state physics, the valence band and conduction band are the bands closest to the Fermi level and thus determine the electrical conductivity of the solid. In non-metals, the valence band is the highest range of [[protons] energies in which electrons are normally present at absolute zero temperature, while the conduction band is the lowest range of vacant electronic states. On a graph of the electronic band structure of a material, the valence band is located below the Fermi level, while the conduction band is located above it.
The distinction between the valence and conduction bands is meaningless in metals, because conduction occurs in one or more partially filled bands that take on the properties of both the valence and conduction bands.

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  1. Mohammad-gl

    A How can I distinguish degeneracy from band structure?

  2. S

    A Momentum density of silicon valence band using bandstructure

    I have included the resulting histogram that emerges when I do this procedure and it does not look as expected. I am using CASTEP and have read the .bands file as a txt file into python where i have extracted the relevant data.
  3. P

    Semiconductor -- Conduction and Valence bands

    I am a new to this and I try to understand the basics. So initially once the atoms of silicon come together to form a solid, due to Pauli law no electrons can exist in the same energy state,thus many energy states are formed which together make the bands. My problem starts at this stage where I...
  4. Athenian

    I Energy of Conduction and Valence Band in Opposing Directions

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  6. PainterGuy

    B What Does Not Allowed in Quantum Theory Mean Regarding Band Gaps?

    Hi, Could you please help me with the queries below? Question 1: Please have a look on the attachment, conduction_band2, or check the following link for better resolution http://imagizer.imageshack.us/a/img921/4356/vODcjh.jpg It says, "Figure 1–7 shows energy diagrams for insulators...
  7. N

    I Valence band and Fermi level difference?

    I was wondering what the difference was between the valence band and fermi level? How do we distinguish between the two? Thanks in advance.
  8. Pushoam

    Conduction band, valence band and Fermi energy

    Homework Statement Homework EquationsThe Attempt at a Solution The probability of getting a state with energy ## E_v## is ## \frac { N_v } { N_v +N_c } = \frac1{ e^{-(E_v – E_f)/k_BT} +1} ## ………….(1) Since, ## E_v < E_f, e^{-(E_v – E_f)/k_BT}>>1 ## as ## E_f – E_v>> k_BT ##……….(2) So...
  9. nmbr28albert

    I Why is the valence band maxima at k = 0?

    In general, materials are either direct or indirect materials. For direct materials, both the valence band maxima and the conduction band minima are at k = 0. For indirect materials, only the valence band maxima is at k = 0 and the conduction band minima is at some other non-zero value of k. In...
  10. A

    Is it possible to shift the fermi level?

    I know we can shift the fermi level by doping the material with other elements. In case of semiconductors doping with the pentavalent or trivalent will change the fermi level. But my question is ''can we shift the fermi level, without altering the position of valence band and conduction band?"...
  11. C

    Density of holes in valence band

    When electrons leave the valence band and jump over the gap to the conduction band, what is the density of the remaining holes? If 2.5 electrons/cm^3 leave the VB to the CB, will the density of remaining holes be 2.5 electrons/cm^3? To me it is logical, but I am wondering if mass of electron...
  12. A

    Why conductors bonds in such way that leaves the valence band not full

    Hi, Iam trying to understand the differences between metals, semiconductors and insulators. Regarding the conductivity properties. Iam new to this area so please correct me if I am wrong. I may be simplifying things now; 1) If I put a voltage over a solid, I only measure a current if...
  13. F

    Valence Band Mixing: What Is It & What Are References?

    What does "valence band mixing" means? Could you provide me some reference about it?
  14. O

    Can electron stay between donor energy level and valence band?

    In n-type semiconductor, Can electron stay between donor energy level and valence band? Can I say that the donor energy level here refer to the Fermi level? Thank you
  15. F

    Valence Band Shift of n-Type Semiconductor

    What does it mean if the valence band of a n-type semiconductor shifts towards lower binding energy after deposition of a metal on-top. Is it simply charge transfer from the metal towards the semiconductor or vice versa? I mean , the valence band is fully occupied, so there are no states for the...
  16. R

    Are electrons in Valence band delocalized?

    Wikipedia says that "in band theory, energy bands are actually made up of many discrete energy levels which are too close together to resolve. Within a band the number of levels is of the order of the number of atoms in the crystal, so although electrons are actually restricted to these...
  17. N

    Are there free electrons in the valence band?

    If not: then how do the holes in a semiconductor manage to conduct electricity (if they can't travel through the solid)? If there are: 1) then what is the difference between the valence and the conduction band? 2) then why do the electrons in a semiconductor need to reach the conduction band to...
  18. T

    Conduction and valence band for metals

    for metals the conduction and valence bands overlap. So how do you distinguish between the conduction and valence bands? How do you find out the lower limit of the conduction band and the higher limit of the valence band? Or is it the case that the highest conduction band in a metal goes from...
  19. N

    Do semiconductors have to have a full valence band?

    Hello, In my book it says that semiconductors have a full valence band and a fermi energy somewhere in between that valence band and the conduction band. But its two examples of semiconductors, crystals of Silicon or Germanium, have a 3s^2 3p^2 resp. 4s^2 4p^2 outer shell, so surely they...
  20. P

    Delat energy required to excite hole from lowest energy orbit to valence band?

    Delta energy required to excite hole from lowest energy orbit to valence band? I have calculated the orbit of a hole in its lowest energy orbit, but am struggling to work out \delta\epsilon (energy needed to excite it to valence band). Any help much appreciated.
  21. B

    Building blocks of the conduction and valence band

    Hi folks, I am new to PF. First I have to apologize for the following english -- it is not my native language. I have problems in understanding the formation of the conduction and valence bands of solids: For example in III-V compound semiconductors both constituents are sp3 hybridized...
  22. D

    Study Valence Band of Iron: Spin-Resolved Photoemission & Inverse Photoemission

    Hi Community! I have to study the valence bad of Iron. Could anyone suggest me some articles where spin-resolved photoemission and inverse photoemission experiments are presented? Obviously textbooks are welcome too :smile: Thanks!
  23. I

    Transition from valence band to conduction at T above 0K + procedure

    we know that at temperature above 0K, in semiconductor some electron collecting sufficient energy fron surroundings to cross the band gap, placed in the conduction band. But what's the actual procedure to make the transition. I mean to say is it direct absorption of IR photons or by some other...
  24. A

    Delocalization of states in valence band du to doping

    How delocalization of the states in the valence band occurs. Can somebody explain how many kinds of localization of states are there in semiconductors.
  25. M

    E-K Diagrams, valence band, conduction band

    I'm having difficulty figuring out how to work this problem: Assume a material has a given E-K diagram: E(K)conduction = Ec + E1 * sin^2 (Ka) E(K)valence = Ev - E2 * sin^2 (Ka) a=0.5nm E1 = 5eV E2 = 4eV I have to: * sketch the E-K diagram for the first brillouin zone (-pi/a < k <...
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