PN Junction Diode: Diffusion vs. Drift Current

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SUMMARY

The discussion clarifies the distinction between diffusion current and drift current in PN junction diodes. Drift current occurs when electrons move due to an applied electric field from a voltage source, while diffusion current arises from the movement of electrons in response to concentration gradients of other charge carriers within the semiconductor. Drift is influenced by external forces, whereas diffusion is solely driven by the concentration difference of particles, independent of any electric field.

PREREQUISITES
  • Understanding of semiconductor physics
  • Familiarity with PN junction diode operation
  • Knowledge of electric fields and forces
  • Concept of concentration gradients in materials
NEXT STEPS
  • Study the principles of semiconductor physics in detail
  • Learn about the I-V characteristics of PN junction diodes
  • Explore the effects of temperature on drift and diffusion currents
  • Investigate the role of electric fields in semiconductor devices
USEFUL FOR

Electrical engineers, semiconductor physicists, and students studying electronic devices will benefit from this discussion on the fundamental concepts of diffusion and drift currents in PN junction diodes.

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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