Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Hall coefficient

  1. Jan 19, 2007 #1
    hey guyz... i was reading about the hall coefficient...there was 2 equations of the hall coefficient one for the n-type material and one for the p-type.
    iwas thinking if there exist a general one for the intrinsic material and from it we can get this 2 equations.
  2. jcsd
  3. Jan 19, 2007 #2
  4. Jan 19, 2007 #3


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Yes, there does exist a general equation from which all the specific cases can be written down.

    Write down one of the two equations that you have, and someone can show you how that comes from the general equation.

    As for the general equation itself, you can simply look up the Hall Effect, and you will find it.

    Edit: Crossposted with anto again!!
  5. Jan 19, 2007 #4
    for p-type: Rh=1/qp0 q=charge p0=hole concentration
    n-type: Rh=-1/qn0 q=charge(negative) n0=electron concentration

    i was thinking about a general formula for intrinsic and from it we can get this 2 equations...it is Rh=1/q(p0-n0)
    it may be wrong but it looks so logic...but i feel like it should contain ni ???
  6. Jan 19, 2007 #5
    Sure, you can get a more "general" formula for the Hall coefficient if instead of q (the electron charge) you put the charge of the specific carrier, and instead of n or p you put the concentration of the specific carrier. But there is no need for such a generalization since it interests us if the Hall coefficient is positive or negative because it tells us what is the type of carriers (electron or hole) that make the current in the material whose Hall coefficient we know. See the link I gave you.
    Last edited: Jan 19, 2007
  7. Jan 19, 2007 #6
    what u r talking about is the hall coefficient for n-type or p-type ... but what about intrinsic materials???? here is the question
  8. Jan 19, 2007 #7

    Dr Transport

    User Avatar
    Science Advisor
    Gold Member

    You are confused about the meaning of intrinsic. There are always n and p carriers in a semiconductor, intrinsic means that the concentrations are equal. You cannot just add the carrier densities because the mobilities are not equal, you need to take the sum of the n and p contributions.
  9. Jan 20, 2007 #8
    so u mean we have to replace n and p by theere formulas with the mobility? so we can get the the general hall coefficient with respect to mobility of holes and electrons?
  10. Jan 20, 2007 #9

    Dr Transport

    User Avatar
    Science Advisor
    Gold Member

    Yes, you have to account for all the physics.
  11. Jan 20, 2007 #10
    ok i will reveiw the course and study it all and try to get the solution and see if it works tahnk u anyway
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook