The DPA-based HPs exhibit random-oriented crystallographic features, as confirmed by the ring-shaped scattering patterns (Figure ). Similar to the PEAbased system, there was no appreciable signal from the δ-CsPbI3 and PbI2 crystallites in the DPA-based quasi-2D HPs. Although this indicates that DPA can provide stable 3D-like HP lattices, such random-oriented crystallites, together with the distinctive abundance of n=1 and 2 2D HPs, infer inefficient charge transport environments that are likely detrimental to PV applications. To gain an understanding of the chemical interaction between the molecular spacers and precursors, which can affect the crystallographic structures and phase distributions in the films, proton nuclear magnetic resonance ( 1 H-NMR) spectroscopy is conducted on the corresponding precursor solutions. Figure and S16 exhibit 1 H-NMR spectra of the precursor solutions, together with the corresponding solution after dissolving spacer cation-iodide salts, allowing us to identify the chemical changes by the interaction with the inorganic ions.