Do carriers move across a p-n junction at 0 K?

  • #1
Wrichik Basu
Insights Author
Gold Member
2020 Award
1,780
1,615
Often a band diagram is used to explain what happens when two pieces of the same semiconductor, one p-doped, one n-doped, are put together. I am a little confused about it, so here is my question.

Initially and at ##0\mathrm{K}##, the surplus carriers should be confined to their respective acceptor and donor levels, e.g. the flatband diagram would look like follows:

HGBKU.png


Now, there are no free carriers in the system and thus, the electrons from the donor level should not be able to recombine with the holes from the acceptor levels due to spatial detachment.

Of course, provided some temperature, the acceptor and donor carriers would ionize and free carriers would be at disposal for recombination and thus, a depletion zone would form. But at ##0K## it seems to me that this should not happen. In reality, would a depletion zone be formed anyway somehow (are there other relevant physics taking action)?

Here, I'm considering the ideal case in which ##0K## exists. Let us not go into the discussion whether it practically exists or not.
 

Attachments

  • HGBKU.png
    HGBKU.png
    10.1 KB · Views: 399

Answers and Replies

  • #2
35,654
12,218
At 0 K you can't have this electron distribution. Some donor electrons at the border have to fill some of the holes until there is an equilibrium.
 
  • #3
19
4
Ask instead how the behavior changes as the carrier kinetic energy approaches zero: what is the limiting case?
 

Related Threads on Do carriers move across a p-n junction at 0 K?

  • Last Post
Replies
3
Views
2K
Replies
8
Views
6K
Replies
6
Views
6K
Replies
4
Views
925
Replies
5
Views
977
Replies
5
Views
11K
Replies
8
Views
2K
Replies
9
Views
3K
Replies
28
Views
4K
  • Last Post
2
Replies
30
Views
5K
Top