N-Doped Graphene and N-Doped Graphene Acid: Heteroatom Doping for Very Efficient Broad-Band Optical Limiting Performance from UV to NIR

The present work reports on the exceptional optical limiting performance of some recently synthesized nitrogen-doped graphene derivatives (NGs) by substitutional heteroatom doping. In particular, the optical limiting performance of NGs having different nitrogen contents and some NG-based quantum dots is investigated in a broad-band spectral range, from 355 to 1850 nm, using 4 ns laser pulses. The obtained results show that the present N-doped graphene derivatives exhibit very efficient broad-band optical limiting performance, attaining record low values of optical limiting onset (OLon), in particular for NIR wavelengths, significantly lower than those of other previously studied graphene derivatives and other families of benchmark materials for optical limiting. The present results demonstrate that tuning the N-doping of graphene acid is a very powerful and efficient strategy for the enhancement of the OL action of graphene, rendering it the strongest currently known optical limiting material, improving dramatically its potential for various optoelectronic and photonic applications.