On close inspection of the spectral region around the emission band peak (inset of Figure ), it appears that for low loading of perovskite in the composites there was a reduction of lowlying sub-band population, as the emission displays a stronger contribution from the high energy transition. Conversely, by increasing the perovskite content, the low energy transitions became more and more pronounced. In Figure we reported only representative samples, but the composite 90-10 Cs2AgBiCl6-g-C3N4 with the best HER performance was also the sample with the weaker contribution to the broad band by the δ* → LP state transition. These observation points out on the effect of perovskite inclusion in funneling optical excitations to the sites where they can be exploited in photocatalytic processes.