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
    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 :)

  2. steveb

    Senior Member

    Jul 3, 2008
    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.