A conductor, metallic is considered to be containing a sea of mobile electrons. When a diode breakdown happen, we actually have a lot of electrons inside the depletion region that are inside their conduction band. Now if we have a constant potential, but we also have so many free charges, it is totally acceptable that all the charges will flow at once.

But in a conductor, where electrons are constantly exchanging energy to go into Conduction Band, and now if apply same potential, we get heat and resistance.

So what actually differs in two case?

When we can break the Ohmic law for Conductors?

  • $\begingroup$ Just to say, if one says, the amount of mobile electrons are not much in conductors as in broke down diode. I want to say, mobile electrons were far less in diode earlier. And what actually made the diode having the above at last, is not making in conductors. And my question is why? $\endgroup$ Dec 8, 2020 at 10:41

1 Answer 1

  • It would be worthwhile to look at the actual numbers: "lot of electrons" in the depletion region of a semiconductor is still orders of magnitude lower than the concentration of electrons in a typical metal.
  • Just like in a metal, the current flow during diode breakdown encounters resistance and results in generation of heat
  • "in a conductor [...] electrons are constantly exchanging energy to go into Conduction Band" - electrons need not be promoted into the conduction band of a conductor, they are already present there.
  • It is worthwhile to mediate for a minute on the fact that the diode in question is still connected to its power source by conducting wires.
  • $\begingroup$ Thanks for replying, but please clear my below confusions: 1. If the order of magnitude (in depletion region while a breakdown) is still lesser than of a metallic conductor, doesn't it make conductor to behave the same easier? 2. I understand the resistance and heat is generated during diode breakdown, but I am talking about the condition before the diode is destroyed. Also, I am asking the reason for difference in I-v characteristics of conductor and diode after breakdown. $\endgroup$ Dec 8, 2020 at 11:32
  • $\begingroup$ 3. I am sorry for my vague statement, I meant, the valance and conduction band overlaps, so in a real world condition, they must be losing some energy and gaining some. 4. This point makes me wonder too. $\endgroup$ Dec 8, 2020 at 11:34
  • $\begingroup$ I think you need to reformulate your question in a clearer way: what about the diode I-V characteristics that seems to you peculiar? You can add pictures of what the diode and the conductor characteristics look like. $\endgroup$
    – Roger V.
    Dec 8, 2020 at 11:50

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