IKAROS was a great step in testing the tech that we currently have, but that was a probe, an actual ship will require much more going on than we are currently ready for. Also IKAROS was designed with solar cells in the sail to power it, because it was essentially facing the sun and so that worked. If youre in a manned ship, youre not always heading towards the sun, so you would still need an alternative power source, if the solar can generate enough to power a manned vessel like it did the probe.

I think a solar sail would be a good secondary deployable mode of transport and possibly power from solar as well, maybe just to save power if theres no rush or something.