In these experiments, a ‘source’ NV undergoes optically-driven cycles of ionization and recombination to produce a stream of photo-generated carriers, one of which we subsequently capture via a ‘target’ NV several micrometers away. Our observations suggest the formation of bound exciton states with large orbital radii, here enabled through the action of unscreened Coulomb potentials. These states manifest in the form of giant carrier capture cross-sections, orders of magnitude greater than anticipated. Besides their fundamental interest, our results open intriguing prospects in the use of free carriers as a quantum bus to mediate effective interactions between paramagnetic defects in a solid-state chip.