title: Large Area Fabrication of Periodic TiO2 Nanopillars Using Microsphere Photolithography on a Photopatternable Sol-Gel Film.
abstract: The authors demonstrate a unique low cost process to print 2D, submicron size, and high refractive index nanopillars using a direct colloidal-photolithography process. A well collimated i-line source emitting at 365 nm wavelength illuminates a mono layer of silica microspheres of 1 μm diameter deposited on a photosensitive TiO2-based sol-gel layer. No etching process is needed since this layer is directly UV photo patternable like a negative photoresist. Furthermore, this thin layer offers interesting optical properties (high refractive index and optical transparency) and good mechanical and chemical stability and thus can be directly used as a functional microstructure (for PV or sensor applications, for example). The paper describes the modeling of the electric field distribution below the spheres during the illumination process, the photochemistry of the TiO2 sol-gel layer process, and preliminary results of TiO2 nanopillars of around 200 nm in diameter fabricated on a three-inch substrate.
authors.affiliation: †Laboratoire Hubert Curien - UMR CNRS 5516, Université de Lyon F-42000 Saint-Etienne, France.|∥L2CE, Laboratoire des Composants pour le Conversion de l'Energie, CEA/LITEN, Laboratoire d'Innovation pour les Technologies des Energies Nouvelles et des nanomatériaux, F-38054 Grenoble, France.
authors.forename: O
authors.initials: O
authors.lastname: Shavdina
authors.affiliation: †Laboratoire Hubert Curien - UMR CNRS 5516, Université de Lyon F-42000 Saint-Etienne, France.|‡Universite Grenoble Alpes, LMGP, F-38000 Grenoble, France.|§CNRS, LMGP, F-38000 Grenoble, France.
authors.forename: L
authors.initials: L
authors.lastname: Berthod
authors.affiliation: †Laboratoire Hubert Curien - UMR CNRS 5516, Université de Lyon F-42000 Saint-Etienne, France.
authors.forename: T
authors.initials: T
authors.lastname: Kämpfe
authors.affiliation: †Laboratoire Hubert Curien - UMR CNRS 5516, Université de Lyon F-42000 Saint-Etienne, France.
authors.forename: S
authors.initials: S
authors.lastname: Reynaud
authors.affiliation: †Laboratoire Hubert Curien - UMR CNRS 5516, Université de Lyon F-42000 Saint-Etienne, France.
authors.forename: C
authors.initials: C
authors.lastname: Veillas
authors.affiliation: †Laboratoire Hubert Curien - UMR CNRS 5516, Université de Lyon F-42000 Saint-Etienne, France.
authors.forename: I
authors.initials: I
authors.lastname: Verrier
authors.affiliation: ‡Universite Grenoble Alpes, LMGP, F-38000 Grenoble, France.|§CNRS, LMGP, F-38000 Grenoble, France.
authors.forename: M
authors.initials: M
authors.lastname: Langlet
authors.affiliation: †Laboratoire Hubert Curien - UMR CNRS 5516, Université de Lyon F-42000 Saint-Etienne, France.
authors.forename: F
authors.initials: F
authors.lastname: Vocanson
authors.affiliation: ∥L2CE, Laboratoire des Composants pour le Conversion de l'Energie, CEA/LITEN, Laboratoire d'Innovation pour les Technologies des Energies Nouvelles et des nanomatériaux, F-38054 Grenoble, France.
authors.forename: P
authors.initials: P
authors.lastname: Fugier
authors.affiliation: †Laboratoire Hubert Curien - UMR CNRS 5516, Université de Lyon F-42000 Saint-Etienne, France.
authors.forename: Y
authors.initials: Y
authors.lastname: Jourlin
authors.affiliation: ∥L2CE, Laboratoire des Composants pour le Conversion de l'Energie, CEA/LITEN, Laboratoire d'Innovation pour les Technologies des Energies Nouvelles et des nanomatériaux, F-38054 Grenoble, France.
authors.forename: O
authors.initials: O
authors.lastname: Dellea