Tunable photoluminescence of graphene oxide from near-ultraviolet to blue

Photoluminescence (PL) of solution-processed graphene oxide (GO) was tuned from near-ultraviolet to blue region through controlled hydrazine (N ₂H ₄) reduction. The peak shifted from 341 nm to 421 nm as hydrazine concentration increased to 0.3 M. Further reduction of the GO increased the density of small sp ² nucleus and enhanced the interconnectivity of localized sp ² sites. It is deduced that hopping and tunneling effects facilitated the migration of excitons to nonradiative recombination sites, resulting in PL quenching and saturation of PL red-shift.