Comparison of different models of non-local impact ionization for low   noise avalanche photodiodes
  The dead space model of non-local impact ionization has been developed independently by three different research groups in order to include a 'soft' dead space. This paper seeks to compare these models for the first time. The models are fitted to Monte Carlo simulation data and it is found that there are no significant differences between the models except that the Liverpool model cannot be used to fit one data set which has a very soft dead space. Likewise the models give very similar results when used to calculate the excess noise factor for low noise avalanche photodiodes. 
John Stephen Marsland
physics.ins-det