The molecule–substrate interaction plays a key role in charge injection organic-based devices. Charge transfer at molecule–metal interfaces strongly affects the overall physical and magnetic properties of the system, and ultimately the device performance. Here, we report theoretical and experimental evidence of a pronounced charge transfer involving nickel tetraphenyl porphyrin molecules adsorbed on Cu(100). The exceptional charge transfer leads to filling of the higher unoccupied orbitals up to LUMO+3. As a consequence of this strong interaction with the substrate, the porphyrin’s macrocycle sits very close to the surface, forcing the phenyl ligands to bend upwards. Due to this adsorption configuration, scanning tunneling microscopy cannot reliably probe the states related to the macrocycle. We demonstrate that photoemission tomography can instead access the Ni-TPP macrocycle electronic states and determine the reordering and filling of the LUMOs upon adsorption, thereby confirming the remarkable charge transfer predicted by density functional theory calculations.

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Fast XPS data obtained during benzene uptake on Pd{111} are consistent with those obtained during benzene desorption, and both are in accord with the corresponding NEXAFS results. At low coverage the molecule lies flat, is strongly adsorbed, and is characterized by a relatively low C 1s binding energy. At higher coverage, a second form of benzene is also present. This species is strongly tilted with respect to the metal surface. It is characterized by a relatively high C 1s binding energy and a narrower π* resonance:  both attributes are in keeping with its observed weaker adsorption strength. The coverage-dependent change in adsorption geometry from flat to tilted benzene, originally suggested in order to account for the kinetics of acetylene trimerization on Pd{111}, is unequivocally demonstrated.

Since their first appearance, organic-inorganic perovskite absorbers have been capturing the attention of the scientific community. While high efficiency devices highlight the importance of band level alignment, very little is known on the origin of the strong n-doping character observed in the perovskite. Here, by means of a highly accurate photoemission study, we shed light on the energy alignment in perovskite-based devices. Our results suggest that the interaction with the substrate may be the driver for the observed doping in the perovskite samples.

Carbon nanotube (CNT)-modified surfaces unequivocally demonstrate their biocompatibility and ability to boost the electrical activity of neuronal cells cultured on them. Reasons for this effect are still under debate. However, the intimate contact at the membrane level between these thready nanostructures and cells, in combination with their unique electrical properties, seems to play an important role. The entire existing literature exploiting the effect of CNTs on modulating cellular behavior deals with cell cultures grown on purified multiwalled carbon nanotubes (MWNTs) deposited on a supporting surface via drop-casting or mechanical entrapment. Here, for the first time, it is demonstrated that CNTs directly grown on a supporting silicon surface by a chemical vapor deposition (CVD)-assisted technique have the same effect. It is shown that primary neuronal cells developed above a carpet of CVD CNTs form a healthy and functional network. The resulting neuronal network shows increased electrical activity when compared to a similar network developed on a control glass surface. The low cost and high versatility of the here presented CVD-based synthesis process, together with the possibility to create on supporting substrate patterns of any arbitrary shape of CNTs, open up new opportunities for brain-machine interfaces or neuroprosthetic devices.