Spatially Confined Functionalization of Transparent NiO Thin Films with a Luminescent (1,10‐Phenanthroline)tris(2‐thenoyltrifluoroacetonato)europium Monolayer

Transparent MOCVD‐grown NiO films have been functionalized with the luminescent (1,10‐phenanthroline)tris(2‐thenoyltrifluoroacetonato)europium(III) complex [Eu(TTA) 3 phen] by combining sputter activation with a solution synthetic route. To introduce the Eu complex only on selected regions, some areas of the NiO surface were activated by Ar + ion sputtering and then functionalized with 3‐phosphonopropionic acid (CPPA) followed by the anchoring of Eu(TTA) 3 phen through a ligand‐exchange reaction between β‐diketonato ligands and the carboxylic groups of CPPA. The functionalized material was characterized by X‐ray photoelectron, UV/Vis and luminescence spectroscopy. XPS measurements indicated that CPPA prefunctionalization and, in turn, the Eu(TTA) 3 phen anchoring occurs only on the sputter‐activated region, while no anchoring takes place on the unactivated surface. The optical properties of the Eu(TTA) 3 phen–NiO system were evaluated by UV/Vis and luminescence spectroscopy.