There is now a true international economic competition to develop strategic and socio-economic solutions to manage our energy independence as well as our production of greenhouse gas emissions. One of them concerns the production of future low cost solar cells having high conversion efficiency, with the objective of achieving production costs below € 0.5/W by 2030 in Europe. It is in this context that the GENESE project proposes an original approach to allow the conversion of light using a combination of Atomic scale Si sensitizers and/or Ag nanoparticles and rare earth ions coupled to a nanostructuration of the substrate. The objectives are (i) to determine the feasibility of such structures for frequency conversion, and (ii) to identify the most promising structure for sensor such that it benefits from a high absorption cross section and an engineering of the spectral absorption. Such sensors offer a high potential for economic development since the different pathways studied in this project are compatible with the photovoltaic industry.

Ferroelectrics are a fascinating class of materials both from a fundamental standpoint and for their potential applications such as a gate oxide in field-effect transistors for low power logic. The key functionality of ferroelectrics arises because their polarization can be switched between two-stable orientations by application and reversal of an electrical field. However, in epitaxial ultrathin films on a semiconductor, a perpendicular polar state may not be switchable due to incomplete screening and depolarization field issues. The project INTENSE is devoted to the study of ferroelectric nanodomains in the complex oxide BaTiO3 epitaxially grown on semiconductor planar- or nanowire-platform. The overarching objective is to understand and control, in ultrathin films (< 50 unit cells), the conditions favoring a bi-stable perpendicular polar state and engineer the nanodomain pattern for their future integration. The challenges to be solved are diverse: i) there are materials issues related to thermal strain, lattice mismatch and depolarization field effects – ii) there are nanocharacterization challenges as both the crystalline and ferroelectric domains on semiconductors appear to be non-periodic and display nanometer size. In addition, phenomena at interfaces such as surface rumpling and ionic contributions to screening are of paramount importance. To address these different challenges, the consortium gathers three academic laboratories (INL, CEMES, IMEP-LAHC) to leverage their unique and complementary expertises in i) epitaxy by both MBE and CVD/ALD for monolithic integration of oxides on semiconductors, ii) structural nanocharacterization using advanced TEM techniques such as HRTEM, dark holography or High Angle Annular Dark Field imaging and iii) advanced electrical and electro-mechanical nanocharacterization based on atomic force microscopy. Within INTENSE, we address for the first time the ferroelectricity of BaTiO3 on various semiconductor substrates: planar Si1-xGex (0

The development of rechargeable batteries is of considerable importance due to the increasing energy consumption of portable devices. Over the past 20 years, lithium-ion batteries have been under intense research due to their advantages such as high energy density, high operating voltage and low self-discharge rate. However, the gravimetric energy density of such Li-ion batteries is known to be limited to 250 Wh.kg-1, which is not enough to meet the ideal electric vehicle requirements for instance. Moreover, most of positive electrode materials are toxic, expensive, and usually have safety issues. Elemental sulfur is a promising positive electrode material for lithium batteries due to its high theoretical specific capacity of about 1675 mAh.g-1 of sulfur material. The discharge potential is around 2.1 V (vs. Li+/Li), and the complete Li/S system should allow to reach a gravimetric energy density close to 500 Wh.kg-1. In addition, elemental sulfur is readily available and non-toxic, advantages that should allow to produce cheap and safe high energy batteries. This technology has attracted attention of the electrochemistry community for many years. However, this promising system still suffers from several drawbacks: low discharge capacity, poor cycle life, low coulombic efficiency, high self-discharge and use of the highly reactive lithium metal negative electrode, which may lead to dendrites formation, short-circuits and explosions. The objective of the PERSEPOLIS project will be to improve the lithium/sulfur system. More particularly, the project will aim at developing a protection for lithium metal negative electrode in order to prevent the dendrites formation as well as to improve the system performances. Thus, the project objective will be dual: • The first goal will be related to safety: the negative electrode protection should prevent the dendrites formation, thus improving the safety of lithium metal electrode during cycling. • The second goal will be related to performances: the negative electrode protection should help to decrease self-discharge and to improve the coulombic efficiency simultaneously. To this purpose, three different strategies will be considered in this project to protect the lithium metal electrode: organic protections will be developed by looking at efficient polymer layers and electrolyte additives; inorganic protective layers will also be investigated by looking at ceramic electrolyte materials; finally, both organic and inorganic solutions will be combined in order to provide a multilayered solution that would further improve electrochemical performances. The developed protective layer solutions will then be tested in full lithium/sulfur cells and thoroughly characterized.

ANTIPODE is a fundamental research project which aims to deeply understand the formation of III-V/Si semiconductor interfaces in order to better control the defect generation at the interface during epitaxial growth. The project proposes to investigate three different III-V semiconductor materials, not only because they are all highly relevant for photonic applications (from UV to IR), but also because they allow to span the nucleation strain from compressive to tensile and close to zero. Although quite different, these three semiconductor materials exhibit a common 3D nucleation growth mode during the very-early stage of the growth on silicon substrates. This project mainly dedicated to state of the art characterization and modeling tools, aims to provide a unified and helpful understanding of III-V/Si semiconductor interfaces and their electronic properties. On December 10, 2012 IBM announced a breakthrough optical communication technology which has been verified in a manufacturing environment. This technology breakthrough allows the integration of different optical components side-by-side with electrical circuits on a single silicon chip, for the first time, in standard 90nm semiconductor fabrication. Despite the very promising results obtained with this “combined front-end” optical on-chip integration, the development of laser sources on chip is still the limiting issue in this integration scheme. To increase the level of photonics integration in a mid-term perspective, one of the most powerful and economical way is to perform the direct epitaxy of III-V semiconductors on the silicon chip. This idea has been widely studied in the early 80’s, where III-V on silicon devices were realized at an advanced level especially by growing the well-known GaAs directly on silicon. In these works, crystalline defects were found to be generated mainly at the III-V/Si heterointerface, and propagating in the volume. This route was revisited recently by three leading French laboratories which demonstrated advanced III-V optical functionalities/emitters on silicon with the growth of respectively the GaSb/AlSb (at IES Montpellier), GaP/AlP (at FOTON Rennes) and GaN/AlN (at CRHEA Valbonne) materials systems on Si. The heteroepitaxy of these materials on Si at the “front-end” level would be a very promising industrial solution provided that the III-V optical active area remains very close to the III-V/Si interface (typically below 300 nm) to increase the level of integration. In this context, the common strategies to manage the defects limitation engineering are not pertinent, as they require thick III-V buffer layers. The only solution is to control the defects generation at the III-V/Si interface and limit their propagation. From their previous experience, IES, FOTON and CRHEA acknowledge the same fact: the overall III-V materials quality is fully determined by the quality of the interface, i.e. by the initial Si surface, and the first III-V monolayers. Partners of the ANTIPODE project will study the initial stages of III-V/Si nucleation by MBE. To this end, they will benefit from the control of the initial Si surface (UHVCVD-MBE growth cluster), state-of-the-art advanced structural/electronic characterizations in three internationally recognized laboratories (HRTEM or STEM-HAADF available at CEMES-Toulouse and LPN-Marcoussis, synchrotron XRD or STM-BEEM available at IPR-Rennes) and theoretical support (atomic relaxation models, DFT, local charges and dipole). The ANTIPODE project is built around the three following objectives: O-I - understanding the 3D nucleation mechanism of III-V semiconductors on silicon (including generation of defects during coalescence) and the strain relaxation mechanisms. O-II - understanding the nature and role of the interfacial charges (in both III-V/Si interfaces and III-V defects interfaces) on the growth and defects generation. O-III - understanding of the influence of the initial silicon surface.

Today, it is not possible to perform COHERENT Transmission Electron Microscopy with subpicosecond temporal resolution. Indeed, the ultrafast Transmission Electron Microscopes (UTEM) developed so far are all based on flat photocathodes. The poor spatial coherence, brightness and spectral resolution of these electron sources impede their use for the most demanding time-resolved TEM applications. The FemTOTEM project is radically different from the other UTEM projects : its aims at developing the first UTEM based on a high brightness laser-driven field emission electron source. This will be achieved by bringing together a femtosecond laser source and a customized cold-field emission Transmission Electron Microscope (CFEG-TEM). This unique combination of femtosecond time resolution, high brightness (allowing high spatial resolution and coherence of electrons) and energy resolution will have an unrivalled potential for frontier research in nanophysics and materials science. The first part of this project involves instrumental developments. First, we will demonstrate and characterize laser driven field emission from the customized electron source of a commercial 200kV TEM. The femtosecond cold field emission gun that we have already mounted in a dedicated Ultra High Vacuum (UHV) bench will be completely characterized in terms of emitted current and energy spectrum as a function of laser parameters and extraction voltage. Then, it will be transferred on a TEM column. Its potential for electron microscopy experiments will be thoroughly investigated first on routine TEM applications and later on more demanding experiments such as electron holography. A new attachment allowing for light injection and collection on the TEM sample, already designed, will enable us to perform original experiments involving electrons and photons. The second part of the project will demonstrate the potential of the new ultrafast coherent TEM on three cutting edge applications. These are nanometer scale, picosecond-resolved Cathodoluminescence (pTRCL) experiments, nanometer scale, high spectral resolution Electron Energy Gain Spectroscopy (EEGS) and ultrafast electron holography. We will demonstrate the measurement of the picosecond luminescence dynamics of individual quantum emitters even in complex or closely packed environments, which is out of reach of the best available pTRCL set-ups, thanks to an expected 6 orders of magnitude increase in brightness. This should allow deepening our understanding of exciton physics in confined systems with numerous applications in photodetection, light emission, single photon sources... The EEGS experiments that we propose are also disruptive experiments going beyond current state of the art in plasmonics and nano-optics. Finally, we will perform the first time-resolved coherent electron microscopy experiments. The fundamental aspects of electron interferometry with non-stochastic electron emission will be investigated first and followed by time-resolved electron holography with applications in nanomagnetism and nanomechanics. Our consortium brings together the complementary skills and expertise to overcome well-identified challenges. This project will provide a unique tool enabling the time resolved investigation of dynamical processes in many fields of physics such as nano-optics, mechanics or magnetism with nanometer spatial resolution. Such a breakthrough in the field of experimental physics will open a wide range of unexplored routes in nanoscience, chemistry and fundamental physics.