Dear Milimo AMOS Nalianya ,

The semicondcutor performance characteristics are determined basically experimentally. They are normally measured. They can also be calculated.

These parameters are the energy gap, the electron affinity, the mobility and the minority carrier lifetime, the doping concentration ... etc. These parameters can be found in the literature of the semicondcutor materials and electronic devices.

As an example I would like that you follow the paper in the link:Article Investigation of lead-free MASnI3-MASnIBr2 tandem solar cell...

For the basics of the materials and devices please refer to:Chapter Solar cells and arrays: Principles, analysis and design

The question as it stands can not be understood?

Best wishes