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!

Homework Help: Semiconductors, number density of charge carriers.

  1. May 11, 2014 #1
    1. The problem statement, all variables and given/known data


    It's the third part which I'm stuck on.

    2. Relevant equations


    3. The attempt at a solution

    I've substituted in all the numbers and, multiplied by the density but I am still not getting the correct answer; where a I going wrong?

    I got

    6.13*(10^11) m^-3

    The answer given is

    1.6*(10^12) m^-3
  2. jcsd
  3. May 11, 2014 #2


    User Avatar
    2017 Award

    Staff: Mentor

    "Third part" means the undoped silicon?
    There is no way to tell if you just show your answer instead of the actual work.
    What did you use as room temperature?
  4. May 11, 2014 #3
    I took 298K as room temperature; and yes sorry I meant the part with the undoped silicon.
  5. May 11, 2014 #4


    User Avatar
    2017 Award

    Staff: Mentor

    That is the number of electrons. You also have holes as charge carriers.

    I get the given answer as rounded result with 300K instead of 298K.
  6. May 11, 2014 #5
    Ahh the holes! I completely forgot, kicking myself now! Thank you!
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted