This code works for me for creating Sphere lights:
l = UsdLux.SphereLight.Define(world.stage, Sdf.Path(some_prim_path))
l.CreateExposureAttr(...)
l.CreateRadiusAttr(...)
l.AddTranslateOp()
XFormPrim(some_prim_path).set_local_pose(translation=...)
You could use UsdLux.DomeLight for dome lights.