PN Junction Diode: Diffusion vs. Drift Current

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Discussion Overview

The discussion focuses on the differences between diffusion current and drift current in the context of PN junction diodes. Participants explore the mechanisms behind each type of current, including the roles of electric fields and concentration gradients.

Discussion Character

  • Technical explanation, Conceptual clarification, Debate/contested

Main Points Raised

  • Some participants define drift current as the movement of electrons in response to an electric field generated by an applied voltage source.
  • Others describe diffusion current as the movement of electrons driven by the concentration gradient of particles, rather than by an electric field.
  • One participant emphasizes that drift is due to an applied force, while diffusion occurs without any external force, solely due to concentration differences.
  • There is a claim that diffusion is not influenced by electric fields, contradicting some earlier statements about its relationship to electric fields from other electrons or holes.

Areas of Agreement / Disagreement

Participants express differing views on the role of electric fields in diffusion current, indicating that the discussion remains unresolved with multiple competing perspectives on the definitions and mechanisms involved.

Contextual Notes

Some statements rely on specific interpretations of electric fields and concentration gradients, which may not be universally agreed upon. The discussion does not clarify the precise conditions under which each type of current dominates.

Dr. Manoj
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What exactly is difference between diffusion current and drift current?
 
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Drift is when electrons move in response to the electric field from an applied voltage source. Diffusion is when electrons move in response to the electric field from other electrons/holes in the semiconductor.
 
OmegaKV said:
Drift is when electrons move in response to the electric field from an applied voltage source. Diffusion is when electrons move in response to the electric field from other electrons/holes in the semiconductor.
Drift is due to an applied force while diffusion is only because of the concentration gradient of particles. Particles move from the region with high concentration to anywhere with lower concentration with no force.
 
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OmegaKV said:
Diffusion is when electrons move in response to the electric field from other electrons/holes in the semiconductor.
Diffusion is not in response to any electric filed. It is only caused by concentration gradient.
 

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