We see in Figure 3 g that the LG peak dominates the emission at low excitation density in the fully treated sample . We note that the results for low excitation density are consistent with our macro - PL measurements performed at similar fluence ( Figure 1b ) . At higher excitation density ( Figure 3h ) , the initial t = 4 ns PL snapshot is also dominated by the LG emission though the relative fraction of the WG peak is higher than in the lower excitation density case . The PL signal of the LG peak plotted over the charge - carrier density for the fully treated sample also shows deviation from a bimolecular dependence ( Figure 3i ) . Since the LG domains grow in size as the light treatment continues toward completion ( cf . Figure 2h ) , we expect less Auger Adv . Mater . 2019 , 31,1902374 ) ( g , h ) . c , f , i ) The initial peak intensity corresponding to WG and LG energies just after pulse excitation ( which were extracted from fits to the spectra with Gaussian functions ) as a function of charge excitation density . Dashed lines in ( c ) denote a second - order recombination rate ; in ( f ) and ( i ) , these bimolecular lines are shifted appropriately as a guide to the eye to the appropriate data set . recombination in the fully treated film as carriers are in fact less concentrated compared to the partially treated sample . Nevertheless , Auger recombination does still reduce the fraction of LG ( compared to WG ) at higher fluence , which is indicative of significant carrier accumulation in the LG - rich surface . Again , we suggest that the slight deviation of the WG from the bimolecular dependence is due to fast energy transfer from the WG to LG regions at high excitation fluence . In addition , we again observe a decrease in the LG peak fraction after the initial pulse as time proceeds in the fully treated film ( Figure 3g , h ) , which is due to enhanced effective charge densities within the LG regions .