Clarification on Implants and Doping in Allpix Squared

Hello everyone,

I’m currently working with Allpix2 and have encountered a few concepts that I’d like to clarify.

In the documentation, it’s mentioned that I can define “implants” within the sensor to represent different physical structures, such as collection diodes or ohmic volumes. However, I’m wondering if these implants are related to the semiconductor doping process, or if they simply represent areas where charge carriers are stopped.

Additionally, I’ve noticed that it’s possible to add doping profiles to the detector using the “DopingProfileReader” module. Are implants and doping profiles separate concepts in Allpix Squared, or is there a connection between them?

Thank you in advance for your assistance!

Best regards,

Hi @Silvia ,

welcome to our forum!

The implants that you can define in the detector models are indeed what you say, the only impact on the simulation is that the charge carrier propagation is stopped when an implant has been reached. At some point we’d like to add different implant materials, in that case it would also imply a difference in multiple scattering and energy deposition, but that’s not part of the master branch or any release.

If the implants should also be reflected in the simulation, this requires input from your side: the electric field, the weighting potential and, if required, the doping profiles should correspond to these implants (or the other way round, to be fair: the implants should match your input fields and doping profile).

So, of course, physically they would correspond to the doping process, but the framework does not translate that into the simulation, but that would need to be done on your side, e.g. through the DopingProfileReader.

Please let us know if this answers your questions or induces new ones.


ok ,Thank you for the detailed explanation ! Your response has certainly addressed my questions.