What is the energy conversion in a forward biased silicon diode?

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Discussion Overview

The discussion revolves around the energy conversion processes in a forward biased silicon diode, specifically focusing on the nature of energy conversion at the junction and the implications of potential and kinetic energy in this context.

Discussion Character

  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant questions whether the energy converted in a forward biased silicon diode is solely thermal energy, suggesting that potential energy from the electric field in the pn junction may also play a role.
  • Another participant asserts that unless the diode is an LED, the primary energy release is as heat, but acknowledges the potential energy associated with electrons crossing the junction.
  • A participant challenges the idea that potential energy could convert to kinetic energy without affecting the overall energy balance across the diode, raising concerns about the implications for the voltage difference.
  • Another participant points out that electrons in the metal cannot gain kinetic energy freely and emphasizes that their potential energy would change, which relates to the observed voltage difference.

Areas of Agreement / Disagreement

Participants express differing views on the nature of energy conversion in the diode, particularly regarding the roles of thermal energy and potential energy, indicating that the discussion remains unresolved.

Contextual Notes

There are assumptions regarding the behavior of electrons in the diode and the definitions of energy types that are not fully explored, leading to potential ambiguities in the discussion.

MHD93
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A typical silicon diode has potential difference of 0.7V when forward biased, to what kind of energy is the (0.7V)*(I)*([itex]\Delta[/itex]t) converted? thermal energy only? isn't there potential energy through the electric field in the pn junction?
 
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Unless you have an LED, the energy is released mainly as heat.
isn't there potential energy through the electric field in the pn junction?
For every electron, sure. And if electrons cross the junction, they release this energy.
 
And if electrons cross the junction, they release this energy.
If this potential energy were released into kinetic, then there's no net change in electrons' energy across the diode, and therefore [itex]\Delta[/itex]V is zero not 0.7V. what's wrong?
 
Kinetic energy of what?
Electrons are not free in the metal, they cannot just get kinetic energy and "fly in some direction".
Even then, their potential energy would change, and you have a voltage difference.
 

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