I am working on the simulation of a solar cell and I am using a ternary compound, for the gap the "Vegard's law" applies, but what about the electron affinity? Is there a relationship I can use?
There is at least one important difference: electron affinity is a molecular property described by molecular orbital energies, while band gap is a solid state porperty described by band theory. Similarly the ionization potential is a molecular property while the work function is a solid state property.
For a relationship between Band Gap BG and Electron Affinity EA you need a third quantity, the ionization energy IE defined relative to Fermi energy EF, valence band energy EV and conduction band energy EC:
-IE=EF-EV
-EA=EC-EF
So it's EG=EC-EV=IE+EA
Edit: with respect to the previous answer, it is correct that people in molecular physics use the electron affinity more commonly but the quantity is also defined for a solid.
Dear Fernando Ayala Mató ,
I agree with the answer of Jürgen Weippert , you should find third parameter combine the different two items you have been mentioned.
Thanks to everyone for your answers.
I think I did not formulate my question well. My compound is a ternary that according to its molar composition I can modify the gap. This material complies with Vegard's law. Is there a similar law that relates the molar composition to electroaffinity(EA)?
As Jürgen Weippert has replied, Electron affinity is strongly related to Ionization energies and according to the work of "Munier et al" you can estimate this value by means of the equations detailed hereby, please check:
Article The Calculation of the Electron Affinity of Atoms and Molecules
Best,
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