Electron Current/movement in P-N junction under forward bias

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Discussion Overview

The discussion focuses on the behavior of electron movement and current in a P-N junction under forward bias, particularly at the interface where the P side meets the circuit. Participants explore the dynamics of hole and electron currents and the implications for circuit functionality.

Discussion Character

  • Exploratory, Technical explanation, Conceptual clarification

Main Points Raised

  • One participant expresses confusion about the flow of electrons from the P side of the junction, questioning how electron current can be zero at that point while still allowing for electron flow towards the positive side of the applied voltage.
  • Another participant mentions the need to form a non-rectifying Schottky junction to connect the semiconductor to the copper conductor, suggesting this junction affects the measurement of built-in voltage.
  • A follow-up question arises regarding whether these junctions are referred to as "contacts," to which a participant confirms this terminology.

Areas of Agreement / Disagreement

The discussion includes varying levels of understanding about the behavior of currents in P-N junctions, with some participants providing technical insights while others seek clarification. No consensus is reached on the initial participant's confusion regarding electron flow.

Contextual Notes

There are assumptions about the behavior of currents and junction types that may not be fully articulated, and the discussion does not resolve the participant's initial query about electron movement.

MaestroBach
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TL;DR
I've been studying p-n junctions and have noticed that I seem to be not understanding something pretty fundamental regarding holes and electrons in both circuits and in p-n junctions.
For context, I have very little background knowledge of circuits.

I'm reading about P-N junctions under forward and reverse bias, and I'm having a bit of trouble visualizing what's happening where the P side of the junction meets the circuit under forward bias.

From what I understand, at the very end of the P side of the junction, there is only hole current and the electron current goes to 0. But given that for the circuit to actually work, electrons have to flow towards the + side of the applied voltage, wouldn't there need to be a flow of electrons out of the P side of the junction? How would that happen when the electron current inside the diode at the far end of the P side is 0?

Please let me know if I"m being unclear with what I'm trying to ask. Thanks!
 
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In order to connect the semiconductor to the copper conductor you need to form a non rectifying Schottky junction. IIRC these junctions are also responsible for the disappearance of the builtin voltage outside the diode (you can't measure it with a voltmeter attached to a non powered diode).
 
SredniVashtar said:
In order to connect the semiconductor to the copper conductor you need to form a non rectifying Schottky junction. IIRC these junctions are also responsible for the disappearance of the builtin voltage outside the diode (you can't measure it with a voltmeter attached to a non powered diode).
Ah, would these also be called the "contacts"?
 
MaestroBach said:
Ah, would these also be called the "contacts"?
Yes.
 
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