Rigid shifting bands and Fermi level in EPW

[Philo]

Dear all,

I want to know how we could study the n-type of p-typle doping effects on electron and phonon linewidths by rigidly shifting the Fermi level in EPW. In general, does Fermi energy affect the e-ph interaction matrix elements? I guess it won't be affected by Fermi energy because it is determined by perturbation of self-consistent potential and the Bloch states of electrons according to the formula to calculate the e-ph interaction matrix elements. Moreover, is the variable fermi_energy used to study the doping?

Secondly, we all know that standard DFT calculation will underpredict the bandgap so I think that it is important to directly set the bandgap to the value from experiment or HSE and GW calculation. Are there some variables help to expand and set the bandgap in EPW or QE by rigidly shifting the bands because bandgap plays an important role on phonon-mediated electron transitions?

Thanks for your help.
Philo