Similar to other RP-type systems, the progressive emergences of intermediate-tohigh-n phases are also observed in DPA-based quasi-2D HP compositional space, where such features are manifested at even lower 3D ratios -from ~10% to 25%than the PEA counterparts. The heavier molecular weight of DPA than ThEA or PEA further slows down the diffusion of the spacer in the solution, which thereby attributes to the results. From the 3D ratio of 30 to 90%, the 3D-like phases becomes dominant, which also involves considerable n=1 2D phase. Note that, after 10 hours under ambient condition, though the PL intensity of the intermediate-n phases are slightly enhanced at the low 3D ratios (<20%), overall, no appreciable changes in the spectral features across the compositional space is observed (Figure ). This indicates that DPA spacer manifests excellent stability of the HP lattices, as the two phenyl rings in the molecule can effectively shield the HP lattices from the oxidative species .