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Homework Help: Breakdown voltage

  1. Apr 12, 2008 #1
    Hiya,
    Being a computer science and eng first year student, just trying to understand one artical regarding Breakdown voltage of a pn junction.Could anybody explain me, which diode out of the following have higher breakdown voltage if they have same design parameters such as doping and thickness and why ?
    1. p+-n diode
    2. n+-p diode
     
  2. jcsd
  3. Apr 15, 2008 #2
    Can you clarify your diode notation. It seems ambiguous.

    Chris
     
  4. Apr 15, 2008 #3
    I suppose, i should have rather written as p+nn+. If you are familiar with power rectifiers, it is quite common notation used in there, to denote the high voltage rectifier.
    High voltage rectifiers are fabricated in silicon which is either n-type or p-type.

    1. "p" refers to quantity of the p-type semiconductor for instance boron etc. The + sign shows that boron atoms concentration, we are talking is in the order of greater then 1e18 cm-3 .This much of the boron atom concentration is diffused into the n type silicon to make a rectifier. It is therefore denoted by p+n.

    2. like wise "n " refers to n-type semiconductor for instance phosphorous etc. Again, when the doping concentration is very high, we denote it by n+.

    so same is applicable to other type of the rectifier for instance n+pp+.
     
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