Hi,
Please check if the fermi-level is in the electron or hole band?
If you have a positive fermi-level shift, then you will have a large electron carrier density but zero holes and should focus on the electron mobility.
If you have a zero hole carrier density, you can still have a large mobility (the few carriers can move freely). But the current density is very low and it is a minority of the charge transport.
Hope it helps in your analysis.
Best regards,
Tue