Active emitters based on nanostructured Si

International audienceThe present paper deals with the use of Si-nanoclusters as efficient sensitisers for Er and Nd rare earth ions or as active emitters in Si/SiO 2 Fabry-Perot microcavities. The films have been fabricated using the reactive magnetron sputtering of a silica target. The energy transfer efficiency from Si-nc towards Er ions has been studied as a function of the fabrication parameters (hydrogen rate, annealing temperature) through time resolved PL intensity measurements on Er-doped silicon-rich silica layers. A multilayer approach has been developed to determine the critical parameters such as the optimum Si-nc size and the characteristic interaction distance Si-nc-Er ions which govern the transfer Si-nc-Er. Thus we have found an optimum size of 4 nm for the Si nanocluster and a maximum spacing of 0.4 nm between the Si-nc sensitisers and the Er 3+ ions. First results on the efficient sensitising effect of Si nanocluster towards Nd 3+ ions are also reported. Concerning the optical planar Si/SiO 2 microcavities, spectral, spatial and temporal photoluminescence behaviour of the Si/SiO 2 multilayers confined inside the resonator are studied. The comparison with a reference sample evidences the effect of the distributed Bragg reflectors structure on the intensity enhancement and the directional characteristic of the emission. Biographical notes: Fabrice Gourbilleau received the PhD in Physics from the University of Caen (France) in 1993. Since 1994 he has been in a permanent researcher CNRS position at the Structure des Interfaces et Fonctionnalité des Couches Minces (SIFCOM) laboratory, Caen, France and heads the «Integrated Nanostructure for Microelectronics and Photonics» group. He works on the effects and properties of nanoscaled materials since 1990. He has more recently focused his research on the fabrication by magnetron sputtering and characterisation of nanostructured silicon-based thin films for photonic or microelectronic applications. He has been engaged in several EU and national projects dealing with laser, photovoltaic and photonics applications. He is the author and co-author of more than 80 papers and the holder of one patent. He is the Representative of the Nanosciences for the Region Basse Normandie and is involved in the Transfer of Technology Society for the Creation of Start-Up. Ali Belarouci obtained his PhD in 1999 at the University of Lyon and is currently Research Scientist at the CNRS. His studies concentrate on mesoscopic devices including silicon nanocrystals and rare earth ions. He also worked on waveguide nano-optics devices for applications in optical communication and memory (three years at Montana state University, USA), and on light localisation in nano-cavities (18 months at MESA + Institute, The Netherlands). David Bréard became Engineer from the ENSICAEN Engineering School in 2004. He is currently working toward the PhD Degree at the Structure des Interfaces et Fonctionnalité des Couches Minces (SIFCOM) laboratory. His research is focused on the fabrication and studies of Nd-doped materials for laser applications. Christian Dufour obtained his PhD in 1993 and is currently Professor in Physics (condensed matter) at the University of Caen. He developed a model of ion-matter interaction since 2000', he has then focused his research in the fields of photonics, particularly in the modelling of luminescence properties and optical gain in rare-earth ions and silicon nanograins co-doped silica. He is involved now in electronic structure calculations via the DFT approach in order to explain the role of the Si grain size, the Si-SiO 2 interface and the rare earth environment on the luminescence properties. Richard Rizk received the Doctorat d'Etat Degree in Physics from the University of Paris, France, in 1976. He is currently the Director of Research at the Centre National de la Recherche Scientifique (CNRS) and Heads the Structure des Interfaces et Fonctionnalité des Couches Minces (SIFCOM) laboratory. His current research interests include solid-state physics covering the fields of electronic, optoelectronic and photonic Si-based materials and devices. He is the author or co-author of more than 130 papers, the author of several invited papers and contributions to special issues and books, the Editor of conference proceedings, and the holder of one patent