Arbitrary space charge to bulk boundary model of Auger recombination for semiconductor power diodes

An arbitrary semiconductor junction is used to obtain an equation for junction current density in terms of the conditions at the boundaries between the space charge and the quasineutral bulk regions on each side of the junction. Included are the effects of recombination in the space charge volume as well as bandgap narrowing and ambipolar diffusion effects in the bulk regions at these boundaries. The equation also accounts for the effects of drift field, which is neglected in other theories, and demonstrates that it exerts a form of cross-coupled modulation upon current flow. Under certain conditions, it may be shown that the current density is largely determined by the carrier density gradient at the space charge to bulk boundaries. A solution for carrier density gradient, which is obtained by one integration of the diffusion equation, does not require a precise solution for carrier density profile and may be used to model bulk region Auger recombination with the aid of the derived equation for current density. This contribution may find use in the design of snubber diodes.