Metal-porphyrins on ultra-thin transition metal- oxide layer

We focus on the role of an oxidized ultra-thin buffer-layer in passivating a buried metal substrate. Our evidence proves that, within the same molecule family, the topmost layer oxidation effectively decouples the electronic structure of the molecule from the metal substrate and allows one to
tune the assembling properties.
A. Calloni et al. DOI:10.1016/j.apsusc.2019.144213
anchoring of Co-TPP molecules to the oxygen-passivated Fe(001)

In the last years, a new strategy has been explored. The basic idea is to interpose a single 2D atomic layer between the substrate and the molecules, with the goal of screening the former enough to avoid dramatic changes in the molecular properties. With our strategy, we have coupled a highly reactive metal substrate, such as iron, to heteroaromatic complexes, such as metal-tetra-phenyl porphyrins (MTPP), which maximize their coordination with the substrate by orienting their macrocycle parallel to the surface. On the other hand, Fe(001) surface can be
confined to the topmost layer and form the Fe(001)-p(1 × 1)O surface reconstruction, with oxygen atoms filling the hollow sites of the square iron lattice.
Our results definitely prove that ultra-thin metal oxide layers
help the stabilization of ordered molecular overlayers and preserve the electronic properties characteristic of quasi-free porphyrins at monolayer coverage.

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Cobalt atoms drive the anchoring of Co-TPP molecules to the oxygen-passivated Fe(0 0 1) surface, A. Calloni, M.S. Jagadeesh, G. Bussetti, G. Fratesi, S. Achilli, A. Picone, A. Lodesani, A. Brambilla, C. Goletti, F. Ciccacci, L. Duò, M. Finazzi, A. Goldoni, A. Verdini, L. Floreano, Applied Surface Science 505, 144213 (2020)  
DOI:10.1016/j.apsusc.2019.144213
Ultima modifica il Giovedì, 27 Ottobre 2022 09:31