The lack of interband PL at shorter wavelengths alone is insufficient to conclusively prove that the AuNF emission is generated by the intraband recombination of Auger-excited electrons, as other mechanisms could equally well explain the observation. For example, if only the emission at the L-point is suppressed, interband recombination at the X -point, the second critical point at which interband absorption takes place in gold, could entirely be responsible for the observed PL at longer wavelengths. Another possibility is that it is not Auger-excited, but directly exited intraband emissions. For plasmonic particles with a high surface-to-volume ratio, approximately 10% of the absorption, in the spectral region of the interband transitions, is attributable to surface-assisted intraband excitation of non-thermal electrons within the conduction band. In the absence of interband PL, the emission might be generated by the radiative recombination of those energetic electrons.