Effect of carrier diffusion on operation of avalanche diodes

The effect of carrier diffusion on the performance of avalanche diodes has received little attention in the literature. This letter presents a simple analytical model of the effects of diffusion on device performance, and arrives at an upper frequency limit dictated by the diffusion effect. The model can be used to give a derating factor onto analyses that neglect this parameter. An example of the application of this is given, and the results compared with previously published computer simulations.