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So I've been clearing my concepts about the PN junction upto a deeper level today, and I've got a few questions to ask and clarify my concepts:

In a pn junction, due to diffusion, Only the electrons move from the n region to the p region, despite holes also being a mobile charge carrier, but they move within the boundaries of the covalent bonds created by the semiconductor in the p region

The electrons from the N side diffuse to the P side and recombine with the holes to create the negatively bound ions, simultaneously creating positively charged ions on the other side

The result of this movement of electrons from N to P side, generates a current from P to N side known as the Diffusion current, and also induces an Electric Field opposing the diffusion of electrons, in the direction from N to P

The above is what I read and studied and understood, I want someone to clarify or let me know if it's right.

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Your first proposition, Only the electrons move from the n region to the p region, despite holes also being a mobile charge carrier, but they move within the boundaries of the covalent bonds created by the semiconductor in the p region, betrays your confusion about the concepts you mention. You can limit yourself to "the-current-flows-from-the-anode-to-the-cathode" reasoning and, while this reasoning is far from what one would list among concepts about the PN junction upto a deeper level, in a sense, it has some truth in it. Even without learning about holes, it is sufficient to entitle you to some technician and engineering jobs.

If you are serious about clearing your concepts upto a deeper level, take a solid-state physics course from electronic engineering school of your choice. Alternatively, you may choose learning hard way, taking online courses or try self-learning. If so, and when you study electrons and holes in a solid-state-physics context, be sure to notice that the solid-state-physics electron is not a free electron as you see in classical electrodynamics, but a quasiparticle one. Sure, the free electron and the quasiparticle electron are more than just synonyms, but still these are different things. The hole is only a quasiparticle. Hole mobility depends on material, lattice type, impurity concentration, and while electron quasiparticle mobility is typically greater, the hole mobility is non-zero, making your statement about holes moving within the boundaries of the covalent bonds created by the semiconductor in the p region (do you mean, in contrast to [relatively unrestricted] motion of electrons?) obscure if not outright wrong.

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  • \$\begingroup\$ Well, my confusion arises from the fact that holes are simply the holes in the semiconductor atoms which are not bonded due to lack of an electron because of the doping of an tri-valent impurity. So how does the movement of holes work? Since, from what I know, the electron from a neighbouring atom joins in to fill that hole up and so on.. but the hole remains, and remains in the boundaries of the neighbouring semiconductor atoms... so how does it cross the depletion region to get to the N side? \$\endgroup\$
    – SubbSE
    Apr 22 at 19:14
  • \$\begingroup\$ But "the holes" of the solid state physics are not entities belonging in the individual semiconductor atoms. Holes are quasiparticles. The quasiparticle moves in the whole semiconductor body, lattice or polycrystalline. Take a beginner course of solid state physics for electronics engineers, or reverse to "the-current-flows-from-the-anode-to-the-cathode" reasoning. The hole crosses the depletion region to get to the N side exactly the same way as the quasiparticle electron does it. \$\endgroup\$
    – V.V.T
    Apr 23 at 14:31
  • \$\begingroup\$ So the more in-depth explanation to this basically lies in quantum mechanics... I was just trying to have a more clear concept of this so I can prepare myself for my exams, I'm a CS student and we have to learn about semiconductors, diodes, transistors, etc, and so I was trying to have my basics as clear as possible about the PN junction first so that later on I don't have any issues, as the other things are an implementation of PN junction itself, and a better understand of PN junction would help me understand those things better as well :D \$\endgroup\$
    – SubbSE
    Apr 23 at 14:39
  • \$\begingroup\$ However strange the idea may seem before you take the solid-state physics course, in the ideal semiconductor lattice the (quasiparticle) electrons and holes do not interact with individual atoms at all. They move freely through the lattice and interact (through elastic/nonelastic scattering) only with lattice defects. \$\endgroup\$
    – V.V.T
    Apr 23 at 14:43
  • \$\begingroup\$ And a beginner quantum mechanics course may not include the study of quasiparticle phenomena. These phenomena are the subject matter of the solid-state physics course. \$\endgroup\$
    – V.V.T
    Apr 23 at 14:46
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In a pn junction, due to diffusion, Only the electrons move from the n region to the p region, despite holes also being a mobile charge carrier, but they move within the boundaries of the covalent bonds created by the semiconductor in the p region

The electrons move from the n region to the p region by diffusion. I think you are aware, but I will say this explicitly. At the same time, holes move from the p region to the n region.

The electrons from the N side diffuse to the P side and recombine with the holes to create the negatively bound ions, simultaneously creating positively charged ions on the other side

Yes. The p side of the junction becomes negatively charged, and the n side becomes positively charged.

The result of this movement of electrons from N to P side, generates a current from P to N side known as the Diffusion current, and also induces an Electric Field opposing the diffusion of electrons, in the direction from N to P

This movement of electrons from N to P is a current. I would avoid saying it "generates" a current. Also, the movement of holes from P to N is also a current.

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