Semiconductors + p-n junction doubt

Click For Summary

Discussion Overview

The discussion centers on the behavior of electrons and holes in p-n junctions within semiconductors, specifically addressing the nature of holes, their charge, and the process of recombination. The scope includes conceptual understanding and technical explanations related to semiconductor physics.

Discussion Character

  • Conceptual clarification
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant questions how holes, which are described as positively charged, can accept negatively charged electrons without resulting in a neutral charge.
  • Another participant argues that holes do not possess a positive charge in the context of doping, suggesting they are merely vacancies in the lattice rather than charged entities.
  • A request for clarification is made regarding the absence of a positive charge on holes induced by doping.
  • A participant explains that the removal of an electron and a proton from a silicon lattice results in a neutral state, creating a hole that can later be filled by an electron, thus introducing a negative charge.
  • A later post seeks clarification on the term "recombination," questioning whether it implies that electrons and holes pair together.

Areas of Agreement / Disagreement

Participants express differing views on the nature of holes and their charge, with no consensus reached on the characterization of holes in the context of doping. The discussion on recombination also indicates uncertainty about the terminology used.

Contextual Notes

There are unresolved aspects regarding the definitions of charge in the context of holes and the implications of recombination, which may depend on specific interpretations of semiconductor physics.

HyDraZin3
Messages
3
Reaction score
0
When electrons from N region diffuse to P region, the electrons combine with holes to form a -ve negative ion leaving behind a +ve ion in P region.So, my doubt is how the holes accept the electrons and get a negative charge because as the holes are positively charged, when they accept the electron which is negatively charged the net charge should be neutral.


THANKS
 
Physics news on Phys.org
The holes do not have a positive charge, if they are induced by your doping. The holes are just positions in the lattice where no electron is present. As you have a different nucleus with a different charge there, doping gives you holes without any charges.
 
can you tell me the reason why holes do not have a positive charge on induced doping?
 
HyDraZin3 said:
When electrons from N region diffuse to P region, the electrons combine with holes to form a -ve negative ion leaving behind a +ve ion in P region.So, my doubt is how the holes accept the electrons and get a negative charge because as the holes are positively charged, when they accept the electron which is negatively charged the net charge should be neutral.


THANKS

The net charge of the whole structure (p and n regions) is indeed neutral.
The point is that electrons from the n region combine with holes from the p region (so not from the same region). Before recombination both regions were neutral.
As a consequence of recombination, region n looses some electrons so from neutral becomes positive. Region p gains some electrons (or looses some holes) so it becomes negative. Overall, the n and p regions together have zero charge.
 
HyDraZin3 said:
can you tell me the reason why holes do not have a positive charge on induced doping?
Imagine a perfect, neutral lattice of silicon. Now, at a single position, remove one proton from a nucleus and one electron. It is still neutral, as you removed one positive charge and one negative charge. The silicon atom became an aluminium atom, and as you removed one electron there is a position where a new electron from somewhere else can fit in.
You have a hole, but no charge. If an electron moves to this position, you have a filled hole, and a negative charge.
 
Thank you all for your help but i have a question:-In wikipedia it is stated that electrons recombines with holes, exactly what does recombination mean, do electrons and holes pair together?
 

Similar threads

High School What is the purpose of the depletion region in P-N junction semiconductors?
  • · Replies 2 ·
Replies
2
Views
3K
Undergrad Measuring the built-in potential of a pn junction
  • · Replies 10 ·
Replies
10
Views
3K
Undergrad Why diode with larger band gap has larger onset potential?
  • · Replies 7 ·
Replies
7
Views
4K
Undergrad Reverse Bias in P-N Junctions: Why Don't Electrons Diffuse Back?
  • · Replies 4 ·
Replies
4
Views
4K
Undergrad Hall effect in P-type semiconductors: electron-centric heuristic?
  • · Replies 0 ·
Replies
0
Views
3K
Undergrad A question on p-n junction depletion layer
  • · Replies 2 ·
Replies
2
Views
3K
Undergrad Pn junction to reach thermal equilibrium
  • · Replies 7 ·
Replies
7
Views
3K
Undergrad Few basic questions about p-n junction
  • · Replies 12 ·
Replies
12
Views
4K
Graduate How do acceptor energy levels form in p-doped semiconductors?
  • · Replies 2 ·
Replies
2
Views
3K
Graduate What Influences the Depletion Region Thickness in a P-N Junction Diode?
  • · Replies 5 ·
Replies
5
Views
30K