An analytical protocol involving microwave assisted solvent extraction followed by GC/MS and principal component analysis (PCA) of the chromatographic data was used for the characterization of bituminous residues sampled from Neolithic objects recovered from excavations in Italy.

Cesium lead bromide perovskite (CsPbBr3) nanocrystals have raised impressive interest as efficient and stable optoelectronic materials. Size and morphology play important roles in the final performances of these materials and advanced characterization studies are needed to elucidate structural and surface properties. In this work, CsPbBr3 cubic nanocrystals were obtained by colloidal synthesis and characterized by multinuclear Solid State NMR (SSNMR), complemented by X-Ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and optical spectroscopy. The multinuclear NMR approach allowed the different components of the nanocubes to be separately observed. In particular, the surface ligands and their interactions with the nanocubes surface were investigated by 1H and 13C NMR experiments, while the structural investigation of the perovskite nanocubes was addressed by exploiting 207Pb and 133Cs spectral properties in comparison with bulk CsPbBr3. Static 207Pb NMR spectra indicated a possible contribution of chemical shift anisotropy from the 207Pb nuclei of the outer layer. The 133Cs NMR spectra showed signals with different chemical shifts for cesium atoms in at least three regions of the nanocubes, from the inner core to the surface, which were interpreted in terms of cubic layers with different distances from the surface using a simple geometrical model. This interpretation was also supported by 133Cs longitudinal relaxation time measurements.

Mixed-cation lead mixed-halide perovskites are the best candidates for perovskite-based photovoltaics, thanks to their higher efficiency and stability compared to the single-cation single-halide parent compounds. TripleMix (Cs 0.05 MA 0.14 FA 0.81 PbI 2.55 Br 0.45 with FA = formamidinium and MA = methylammonium) is one of the most efficient and stable mixed perovskites for single-junction solar cells. The microscopic reasons why triplecation perovskites perform so well are still under debate. In this work, we investigated the structure and dynamics of TripleMix by exploiting multinuclear solid-state nuclear magnetic resonance (SSNMR), which can provide this information at a level of detail not accessible by other techniques. 133 Cs, 13 C, 1 H, and 207 Pb SSNMR spectra confirmed the inclusion of all ions in the perovskite, without phase segregation. Complementary measurements showed a peculiar longitudinal relaxation behavior for the 1 H and 207 Pb nuclei in TripleMix with respect to single-cation single-halide perovskites, suggesting slower dynamics of both organic cations and halide anions, possibly related to the high photovoltaic performances.