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: Departure from convention?

  1. Oct 30, 2012 #1
    1. The problem statement, all variables and given/known data
    I am reading a chapter on semi-conductors in a text.It talks about n-p type semi-conductors and states that "the potential of the n-side is higher than that of the p-side"

    However, by convention, in case of batteries for example,we designate the negative terminal as lower potential and the positive terminal as higher potential.

    So, what can be the reason behind the author's terminology?

    Thanks.
     
  2. jcsd
  3. Oct 30, 2012 #2

    CWatters

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    P-type material has an excess of holes. N-type material has an excess of electrons. This is the reason they are called P and N type.

    It just happens that when a junction is formed the holes and electrons diffuse across the junction making the P-type side negative and the N-type side positive.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook