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

Leakage current in diode

  1. Apr 13, 2010 #1
    My question is related to the leakage current occuring in a diode when connected in reverse bias mode. When the diode is forward biased, the source voltage first neutralizes the barrier potential and then the flow of current occurs. However, I am not able to understand how the current due minority charges flow through a diode when it is reerse bias.
    I would be very grateful if there is someone who can help me with this confusion.
     
  2. jcsd
  3. Apr 14, 2010 #2
    In reverse, electron-hole pairs are being thermally generated just as in the forward case. For every electron removed from its parent atom, a hole is generated as well. The electrons move when reverse biased, and they encounter holes due to p-type doping. The thermally generated electrons & holes are equal in number, but doping a semiconductor with p-type impurites, i.e. acceptors, results in low electron mobility. The electrons recombine with the abundant holes and few make it to the junction barrier. Likewise, on the n-side, an excess of electrons occur due to doping, and holes have low mobility.

    It's all about mobility of e- & h+ which varies with doping level and whether the semiconductor material is n-type, p-type, or intrinsic.

    Claude
     
    Last edited: Apr 14, 2010
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Leakage current in diode
  1. Current in Diode. (Replies: 2)

Loading...