In the present paper we reported a series of novel 2D perovskites including decylammonium as organic spacer. Novel Ge-and Sn-based bromide and iodide materials are reported and investigated for the first time. DA2Ge(Br1-xIx)4 system showed a strong correlation between structural and optical properties, with two distinct regimes with a step reduction of c- To conclude, the series of novel 2D perovskites presented in this work widen our actual knowledge of structure-property correlations in lead and lead-free systems. In addition, by keeping the same organic spacer (decylammonium), the tuning of central metal and halide allowed to modulate the absorption in the whole visible spectrum and to provide samples with narrow and broad emissions with, in some cases, appreciable quantum yields which can be nicely modulated through halide alloying, a strategy of potential exploitation in other lowdimensional perovskites. The systems presented in this work are clearly of interest in many possible applicative fields, also considering the superior stability of lead-free bromide compounds, and are worth of being further investigated from an experimental and theoretical perspective.