Fractional jet Captain reported landing and missing Taxiway N at PHL as the taxiway was not lit up at all and it was difficult to see the turnoff; especially when it was located next to the brightly lit Taxiway K4.

Narrative

During landing on 27R in PHL at night; we were aware that we had another plane close behind us. The First Officer (FO) did the landing; we were in a position to clear the runway at taxiways L or M; but the Tower Controller said 'continue to N.' We transferred controls; I powered back up to get down to N. When we got there; all I could see were the intensely bright lit-up lights on the high speed K4. N; which is immediately before K4; was completely invisible; did not appear to be lit up at all and I couldn't see a turnoff. Not wanting to take any longer on the runway I turned off on K4 instead; barely in time to let the plane behind us land.Suggestions: They really need to do something about this lighting issue in PHL. It is extremely tricky taxiing around at night there. There are 'black holes' and it is quite disorienting. There were 2 NOTAMs for Taxiway N: 'TWY N CL LGT AT TWY S UNSERVICEABLE' and 'TWY N CL LGT AT TWY J UNSERVICEABLE.' Maybe with Taxiway N being an invisible dark hole at night and located immediately next to one of the most brightly lit high speeds on the airport (K4); the tower controllers shouldn't use it at night for aircraft exiting the runway.