We started our investigation by exploring the role of halide alloying on the DA2Ge(Br1-xIx)4 solid solution with x= 0, 0.15, 0.25, 0.50, 0.75, 0.85, and 1. Concerning the two endmembers, DA2GeI4 has been reported previously by our group in a high-pressure diffraction and spectroscopy work, while DA2GeBr4, as well as the mixed compositions, have, to the best of our knowledge, never been reported before. 17 DA2Ge(Br1-xIx)4 samples were prepared by solution chemistry and a picture of the obtained powders is reported in Figure . As can be seen, sample color moves from light-yellow for x= 0 to dark orange for x= 1. The room temperature (RT) x-ray diffraction (XRD) patterns (Figures and) have the clear features of RP 2D perovskites, with low-angle peaks related to the long c-axis, and are in agreement with our previous results confirming an orthorhombic symmetry (space group Pbca) for the whole the solid solution. All the patterns are strongly dominated by the (00l) reflections typical of the layered perovskites. From Figure , highlighting the first peak of the patterns, it is evident a sudden change of the c-axis between x = 0.25 and x = 0.5. The c-axis is longer for DA2GeBr4 and Br-rich compositions with respect to DA2GeI4 (and I-rich compositions). Such a trend has been already observed by our group in tin-based systems with aliphatic spacers and is related to the staggering of the organic spacer. The evolution of the c-axis as a function of x (iodide content) is presented in Figure ; before and after the jump, the slight change of the long axis is due to the different size of the Br and I anions. UV-Vis spectroscopy spectra for the DA2Ge(Br1-xIx)4 system are reported in Figure .