The SiNaPS laboratory investigates the new physical phenomena appearing when silicon is down-sized to the nanometer scale. Our aim is to unveil new devices based on the understanding of those phenomena and to explore their future applications. Therefore, SiNaPS research span from material growth and nanotechnology to characterization of nanostructure electronic/structural/optical properties, up to prototype nanodevices fabrication.
Our effort is tightly focused on two fields : the physics of silicon and germanium based nanostructures (i.e. nanowires, quantum boxes and nanostructured GeMn alloys) and the optics of wavelength-scale optical microstructures namely photonic crystals and microcavities.
Current research axes
Among the main achievements are, in the field of group IV nanostructures, the growth of sub-5 nm diameter crystalline Si and Ge nanowires, the growth of nanostructured (branched) silicon nanowires, the nanofabrication of porous alumina templates, the growth of nanostructured GeMn alloys containing a high Tc (>400 K) ferromagnetic phase. At the frontier of electronics and optics, we studied the mechanisms of carrier recombination and light emission in silicon-on-insulator (SOI) thin films where we demonstrated the Fermi-Dirac condensation of excitons into a metallic liquid. In the field of nanophotonics, we evidenced the potential of SOI microcavities and photonic crystal structures to control the radiation diagram of photons. We also demonstrated strong (2 orders of magnitude) light extraction enhancement by low group velocity SOI photonic crystals. Finally, we applied our effort to the quest for ultra strong light confinement in high Q nanocavities (Q > 60.000 for V = 0.6(l/n)3 achieved) and to the fabrication of rare-earth (Er) functionalized toroidal whispery gallery mode microresonators for future on chip light generation.
In the reporting period, the laboratory as also launched the virtual laboratory SiNOPTIQ with the Institut Carnot de Bourgogne to pursue research in the field of near-field nanophotonics. At the same time we started, in association with the Laboratoire des Technologies de la Microélectronique, the NanoS platform dedicated to the synthesis of nanostructures and to their assembly into nanodevices.
Research tools, methods
The laboratory operates one MBE and one CVD chamber for the epitaxy of group-IV nanostructures, plus a vacuum e-beam deposition chamber dedicated to the deposition of oxide and metal films. The structural characterization is based on a low temperature STM with in-situ growth capabilities, SEM and TEM equipments located on the Nanocharacterization Platform (PFNC) within Minatec, as well as X-Ray diffraction techniques at the nearby located European Synchrotron Radiation Facility. For nanofabrication, the laboratory makes an intensive use of the Plateforme Technologique Amont (PTA) and also runs close collaborations with CEA and CNRS teams operating at Léti facilities. Along the years, the laboratory has intensively developed spectroscopic characterization tools such as : life time measurements and low temperature spectroscopy, spatially-resolved spectroscopy at the micron scale, wave-guided spectroscopy and also optical near-field microscopy.
The laboratory is now a team of 25 people located on the Minatec Center.
More from SiNaPS team ...
Dr. Emmanuel HADJI
Maj : 20/02/2017 (152)