title: Multilayer Langmuir-Blodgett films as diffractive external 3D photonic crystal in blue OLEDs.
abstract: Three-dimensional Langmuir-Blodgett films made of silica beads are theoretically and experimentally investigated in order to improve the relatively small efficiency of blue OLEDs. Using films made of 5 layers of beads, we fabricated OLEDs emitting at 476 nm, and measured a gain of around 40% on their external quantum efficiency. An optical model has been developed to accurately handle the fact that the organic emitting layer and the photonic extraction layer are separated by a distance greater than 1000 wavelength. The latter also permits to describe rapidly this three-dimensional optical OLED cavity, without redoing all the numerical simulations when the optical properties of the organic layers are changed (material index, thicknesses).
authors.forename: Frédéric
authors.initials: F
authors.lastname: Dumur
authors.forename: Stéphane
authors.initials: S
authors.lastname: Reculusa
authors.forename: Michal
authors.initials: M
authors.lastname: Mruczkiewicz
authors.forename: Mathias
authors.initials: M
authors.lastname: Perrin
authors.forename: Laurence
authors.initials: L
authors.lastname: Vignau
authors.forename: Sophie
authors.initials: S
authors.lastname: Fasquel