I do not have s copy to quote, but I have seen fire code text quoted here that required outside lighting all the way from the building exit to the intended public right of way on the exit route.
Lighting just outside the exit door would be either all or part of that requirement depending on the surroundings of the building.
FWIW, that particular requirement could also be met by a pole mounted light some distance from the exit. At the exit would just be easier to install.
Meanwhile NEC has requirements for outside exit/entry lights for some buildings, but not emergency powered.
Tapatalk!