To add on the IV-curve analysis object vs. IVCharacteristics study object, the latter is a study object (not an analysis object), meaning that it allows doing many things that the IV curve analysis object would not, e.g., restarting calculations from the point where it was stopped (if job crashed or stopped intentionally), adding or removing (V_ds, V_gs) points, calculating physical quantities (transmission spectrum, potentials, electron density, density of states and so) directly in the study object, and many other things.
One thing where the IV curve analysis object might be of use is if for whatever reason one wants to independently set the left and right electrode potentials with respect to a common reference when applying a bias voltage, which is a difference between the left and right potentials. In the IVCharacteristics study object, the right electrode is grounded, i.e., the potential is set to zero by default (at the moment it is not possible to change this default in the study object settings), and the actual bias voltage is applied by changing the left electrode potential. That makes no difference for devices without gate electrodes, but for devices with gates it is important to be aware of this difference between the IVCurve and IVCharacteristics objects.
