Noise due to generation and recombination of carriers in p-n junction transition regions

The theory for the current noise associated with carrier generation and recombination in a
p-n
junction transition region is presented. The noise model is derived directly from the SRH defect center model. In a reverse biased junction the noise from this mechanism varies from two-thirds to full shot noise, depending upon frequency, and in a forward biased junction the noise ranges from three-fourths to full shot noise, depending upon injection level. These results approximately agree with published experimental results, but the agreement is not conclusive, especially in forward biased junctions. The theory shows that the noise associated with transition region generation-recombination current is not particularly significant in bipolar transistors.