X‐ray Avalanche Photodiode Simulator

An x-ray avalanche photodiode (APD) simulator has been developed as part of the EPSRC funded project “High performance X-ray detectors with sub-100eV energy resolution” (EP/I010920/1). It is available for download via the link on the right, as an exe file.

The simulator is based on a random path length model described in [1] and [2]. It calculates the distributions of total number of carriers and avalanche gains, Tv(R) and P(g), respectively for an x-ray APD. The simulator allows the user to specify the following:

  1. avalanche region width, w
  2. impact ionisation coefficient ratio, k
  3. mean avalanche gain, <M>
  4. carrier injection profile.


[1] C. H. Tan, R. B. Gomes, J. P. R. David, A. M. Barnett, D. J. Bassford, J. E. Lees and J. S. Ng, “Avalanche gain and energy resolution of semiconductor X-ray detectors”, IEEE Trans. Electron Dev., vol. 58, pp. 1696-1701, 2011.
Available from http://impact-ionisation.group.shef.ac.uk/journal/

[2] D. S. Ong, K. F. Li, G. J. Rees, J. P. R. David and P. N. Robson, “A simple model to determine multiplication and noise in avalanche photodiodes”, J. Appl. Phys., vol. 83, pp. 3426-3428, 1998.
Available from http://impact-ionisation.group.shef.ac.uk/journal/