Current Density in pn junction Diode

Discussion in 'General Electronics Chat' started by salil87, Nov 4, 2011.

  1. salil87

    Thread Starter New Member

    Nov 4, 2011
    18
    0
    When considering the current density of a pn junction diode in forward bias why are the Electron and Hole current densities added? Aren't they just the one and the same thing. I mean hole is not independent right? It is present only because of an electron. So by adding aren't we doubling the current? Sorry if it's a silly question :)

    Thanks
    Salil
     
  2. steveb

    Senior Member

    Jul 3, 2008
    2,433
    469
    When a hole-electron pair are created in a semiconductor, each charge acts as an independent entity similar to real particles like a electron-positron pair in space. The hole can move in position, hence any current density associated with that movement represents a real component to current density.

    This is fundamentally different than electrons moving in a conductive metal. In the case of standard conduction, the positive charges created in the lattice structure are not movable, relative to the material.
     
    salil87 likes this.
Loading...