L’application visée est celle de l’éclairage arrière d’écrans plats LCD à basse consommation. Le verrou technologique porte sur la réduction de la température de fabrication d’une matrice d’éclairage intelligente à NTC. Une réduction significative du coût du composant (facteur 2 à 3) est attendue en le réalisant sur un verre à bas point de fusion au lieu d’un verre borosilicate. L’objectif du projet est de formuler à partir d’une compréhension approfondie de systèmes modèles un précurseur de croissance de NTC intégrable dans le procédé de fabrication des matrices d’éclairage à NTC dérivé de la filière d’écrans plats à NTC du consortium. L’innovation porte sur la mise au point d’un nanomatériau précurseur intégrable (couche mince nano structuration) équivalent à un alliage PdNi qui sous forme de nano agrégats présente les propriétés visées. Les enjeux scientifiques sont de comprendre et modéliser les mécanismes de croissance par CVD des nano émetteurs à NTC en relation avec la formulation et les caractéristiques physico-chimique des précurseurs. L’enjeu technique est de développer une technologie d’éclairage arrière à NTC bas coût dans la perspective économique d’adresser une partie du marché des 100 millions d’écrans TV LCD prévus en 2010.

To support the upcoming short-term needs of the battery industry, it is imperative to have new differentiating European battery technology for 4b generation batteries on the market from 2025. Halide solid state batteries for ELectric vEhicles aNd Aircrafts (HELENA) responds to the need of the development of a safe, novel high energy efficiency and power density solid state battery (4b generation batteries) cells, based on high capacity Ni-rich cathode (NMC), high-energy Li metal (LiM) anode and Li-ion superionic halide solid electrolyte for application in electric vehicles and, especially in aircrafts. HELENA will support Europe, in this sense, on its transition towards a climate-neutral continent since electric aviation is poised to take off within the next five to 10 years, with innovations already being pursued for electric vehicle batteries. Moreover, HELENA will avoid dependence on Asia for battery production. HELENA is built by a multidisciplinary and highly research experienced consortium that covers the whole battery value chain and proposes a disruptive halide-based solid-state cell technology with the overall aim to significantly increase the adoption of these batteries on aircrafts and EVs The technical challenges that are presented by current conventional battery technology and the consumer needs will be overcome - especially the reduction in costs of battery devices, enable scalable and safe cell manufacturing, increasing their capabilities for long distance traveling and fast charging, ensuring a high safety of the battery.

The project deals with two technologies that involve the use of transparent conductive thin films. The first application is that of "thermal insulation reinforced" glazing. These glazing reflect the infrared radiation to the inside of the building and thus diminish thermal losses. We call them low-emissive glazing. Silver is the most commonly used material for this application, since, showing the highest conductivity, it is the most reflecting. Films have to be very thin, in order to preserve transparency in the visible. The amount of coatings of this kind which are deposited each year is huge, around 100 km2 per year, which represents a market near one milliard euros. Saint-Gobain controls 15% of this market. To keep this part of the market, it is vital to improve the performances still. New applications of transparent conductive thin films have recently been developed, leading to what is known as transparent electronics, used for flat displays, flat light sources (OLEDs), photovoltaic cells, and smart windows. Saint-Gobain is involved in these new markets, which are very big. Sant-Gobain proposes an alternative to the use of traditional transparent conductive oxydes (TCO), such as indium-tin oxide (ITO). The Saint-Gobain solution makes use of very thin films of silver. This should bring an important advantage, because silver is chepaer that indium and its sourcing is more durable. It is thus a real breakthrough. Two technical aspects are to be taken into account when developing the two kinds of products discussed in this proposal : 1. the conductivity of the silver thin films is to be made as high as possible. 2. the nature - ohmic or non-ohmic - of the contact between the silver film and the oxide films on both sides has to be well controlled. COCOTRANS is made of three parts. Two of them deal with the basic understanding of the electron transport on one side, and of the nature of the silver-oxide contact on the other side. The third part is about processes that will be used to improve the characteristics of the final products. When the thickness of the silver layer is decreased, its resistivity increases. This is due to the diminution of the electron mean free path, which comes from the interaction (scattering) of electrons with the film faces (interfaces) and with the grain boundaries. It is difficult to distinguish between these two processes and to evaluate which is dominant. In spite of many studies available in the literature, the answer to this question is not clear. We will revisit it using a totally original approach, in which hot electrons will be used instead of thermalized ones. The hot electrons will be injected on the side of the silver layer with the help of the tip of a Scanning Tunnelling Microscope. This experiment will be complemented by optical spectroscopy of silver films of various thicknesses in a very wide range of frequencies, from which information on the texture of the silver films will be drawn. It will be compared with in situ STM observation of the silver film during its growth on the oxide substrate. The second part of the project will deals with the electrical transport across the silver/oxide interface. The experimental approach will be that of electron spectroscopy and STM spectroscopy during the growth. Use will also be made of I(V) measurements of the interface. In parallel, new processes of deposition of the oxide/silver/oxide stack will be tested in order to improve the quality of the silver/oxide interface in regard of several criteria : size of grains, cleanness of grain boundaries, specularity of the electron reflection at the interface, ohmic or non-ohmic nature of the interface. Various techniques will be used, such as the deposition of a very thin layer of another metal or another oxide at the silver/oxide interface or the planarization of the oxide surface before the silver deposition.