Wireless Anti-Stokes Photo-induced Electrochemiluminescence at Closed Semiconducting Bipolar Electrodes

International audienceWireless electrochemical systems constitute a rapidly developing field. Herein, photo-induced electrochemiluminescence (PECL) is studied at Si-based closed bipolar electrodes (BPEs) for designing anti-Stokes systems that can convert IR into visible photons, without direct electrical contact. We show that protection of the anodic emitting pole of the BPE allows the triggering of bright and longstanding emission under the synergetic actions of an external bias and IR illumination. Photoactive nand p-type Si BPEs are studied with front-side and backside illumination, respectively, and non-photoactive n +-Si BPEs are studied in the dark. Two electrochemiluminescent (ECL) systems ([Ru(bpy) 3 ] 2+ /TPrA and L-012) are tested and we show that the onset bias and the anti-Stokes shift can be controlled by the ECL system that is employed. These advances, rationalized by simulations, will be useful for the design of original PECL systems for chemical sensing or photodetection

Transport in photoelectrochemical heterojunctions: Interface-controlled physics

International audienceWidely investigated in the 70’s and 80’s, photo-electrochemistry of semiconductors (SC-PEC) has regained a huge interest in the context of global warming, especially with the quest of solar fuel production. Considerable advances have indeed been made from those days to understand and tailor the physics of semiconductor photoelectrodes, with the development of protection and catalytic coatings for aqueous operation,[1] and the development of novel electrochemical schemes such as photo-induced electrochemiluminescence.[2]Compared to photovoltaics where solar spectrum harvesting and carrier transport are the main challenges, PEC devices also require the management of the electrolyte/SC interface. In most photoelectrodes, this Schottky-like interface is the heart of the device, enabling to feed the electrolyte with the ad-hoc photo-carrier, depending on the intended chemical reaction. Still, it is also the place where harmful effects can appearsuch as surface trapping and corrosion. Engineering of this interface is thus crucial in view of chemical stability, photovoltage and overpotential optimization.In this talk, we will first introduce the basics of SC photo-electrodes, emphasizing on the conceptual gaps between experiments and numerical simulations of the devices. This will allow us to address the concept of III-V thin films on silicon for PEC where the physics of the device not only depends on the electrolyte/III-V interface but also on the III-V/silicon one and on structural defects with semimetal properties which cross the III-V layer.[3] These novel heterojunctions show promising performances at both poles of PEC cells for solar hydrogen production (see Figure 1)

C-Band Translation by Second-Harmonic Generation in an Orientation-Patterned Gallium Phosphide Waveguide

International audienceOrientation-patterned gallium phosphide (OP-GaP) is studied for frequency combs conversion from C-band to visible. Simulations of periodic and chirped OP-GaP waveguides nonlinear response are presented. Design rules for future developments are established using this study

Fabrication and characterization of zinc sulfide nanowaveguides for 2nd-order nonlinear photonics

International audienceIn this contribution, fabrication and characterization of ZnS is described, and presented as a novel platform for integrated nonlinear photonics

Gallium Phosphide Platforms for Integrated Photonics

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Evaluation de différentes plateformes à base de Phosphure de Gallium et mesures de pertes à 800 nm

International audienceNous comparons ici différentes plateformes de Phosphure de Gallium pour la fabrication de nano-guides d'onde pour des applications de photoniques non-linéaire intégrée. La comparaison des plateformes se fait particulièrement sur l'analyse des pertes à 800 nm, mesurées à l'aide de différentes méthodes

Génération de seconde harmonique dans un guide d’onde en phosphure de gallium à orientation structurée aux longueurs d’onde télécom

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