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O: Fachverband Oberflächenphysik
O 32: Heterogeneous Catalysis I
O 32.4: Talk
Tuesday, March 18, 2025, 11:15–11:30, H25
Synergistic effect of oxygen and water on the environmental reactivity of 2D layered GeAs — •Luca Persichetti1, Giacomo Giorgi2, Luca Lozzi3, Maurizio Passacantando3, Fabrice Bournel4, Jean-Jacques Gallet4, and Luca Camilli1 — 1University of Rome Tor Vergata, Italy — 2University of Perugia, Italy; — 3University of L'Aquila, Italy — 4Sorbonne Université, CNRS, Paris, France
GeAs is a fascinating 2D material with compelling properties stemming from its intrinsic anisotropy. However, it reacts strongly with air, forming a Ge-oxide layer that affects its optoelectronic properties, such as contact resistance and refractive index. Investigating GeAs reactivity under realistic device conditions, including humid O2 and water exposure, is therefore crucial.
At the TEMPO beamline of Soleil, near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) was employed to study GeAs in the presence of oxygen and water. Results showed minimal reactivity with dry O2 and de-aerated water, while slight humidity (Rw = 0.5%, T = 20°C) in an O2 atmosphere significantly enhanced reactivity. Density functional theory calculations confirmed this synergistic effect, revealing a highly exothermic formation energy for the simultaneous chemisorption of O2 and H2O, compared to the adsorption of each molecule individually.
This research was supported by EU-funded MUR programs PRIN2022 ATYPICAL (2022JW8LHZ) and PRIN 2022-PNRR SPIGA (P2022LXNYN).
Keywords: oxidation; germanium arsenide; reactivity; water; oxygen