Effect of carrier diffusion on the breakdown characteristics of avalanche diodes

The effect of carrier diffusion on the breakdown characteristics of GaAs and InP avalanche diodes has been investigated using experimentally reported diffusion constants and ionization rates of electron and holes in semiconductors. The results show that diffusion causes some change in current distribution and electric field profile in the depletion layer of both GaAs and InP diodes. The avalanche zone is widened and the breakdown voltage decreases due to diffusion.