This thesis presents a comparative study between two silver nanoparticle inks that were deposited using a Drop-on-Demand (DoD) inkjet printer, aiming at finding a functional ink that can be used to print electrodes in Light-emitting Electrochemical Cells (LECs). To achieve this, a DoD inkjet printer was installed and an acquaintance with the printer was attained. Among the two inks, one was employed as received while the other was reformulated, and successful deposition of both the inks was observed. During the reformulation process, it was seen that the highly volatile tetrahydrofuran (THF) solvent can be used to improve the ink properties, in contrast to what is recommended. After that, the inks were deposited on UV-ozone treated glass substrates, sintered at an elevated temperature under ambient conditions, and their specific resistances and thicknesses were measured. Finally, the inks were used to print the anode in a structured sandwich-cell LEC. The performance comparison was conducted by observing the emitted light of the LECs. The results indicate that the reformulated ink performs better, probably due to the lower silver concentration that results in flatter surface, which in turn effectively alleviates shorts.

Depuis les années 2000, l'impression fonctionnelle connait un grand succès pour la fabrication de composants électroniques. Elle se positionne de manière complémentaire par rapport aux technologies du silicium et vise principalement les marchés de l'électronique grande surface (écrans, panneaux photovoltaïques) et de l'électronique flexible (RFID, capteurs, textiles intelligents). Dans ce travail, des couches d'argent imprimées par jet d'encre ont été caractérisées en fonction des conditions d'impression et de recuit. L'évolution de leur microstructure, de leurs propriétés électriques et mécaniques a été étudiée. Dans ce cadre, des méthodes expérimentales ont été développées et validées par la bonne corrélation entre les mesures et les modèles. La maîtrise des propriétés de ces couches et l'optimisation de leur procédé de fabrication nous ont conduits à concevoir, fabriquer et caractériser plusieurs composants flexibles: un filtre passe bande centré à 17 GHz sur un substrat polyimide, un micro-capteur de vide fonctionnant sur le principe de Pirani et un bouton-poussoir d'épaisseur inférieure à 250 µm pour des claviers souples. Enfin, des condensateurs RF ont été réalisés par la superposition de couches imprimées diélectriques (BaSrTi) et conductrices (Ag). Les performances des prototypes réalisés sont proches de l'état de l'art et ouvrent la voie à de nouvelles applications pour les technologies d'impression. Cette étude démontre le potentiel des couches d'argent imprimées par jet d'encre pour la fabrication de dispositifs flexibles. / In the last decade, functional printing has gained a large interest for the manufacturing of electronic components. It stands aside to silicon technologies and specifically targets markets of large area devices (screens, photovoltaics) and flexible electronics (RFID antennas, sensors, smart textiles). In this work, inkjet printed silver layers are characterized depending on the printing conditions and the required post-printing annealing. The evolution of their microstructure, electrical and mechanical properties is investigated as a function of the annealing temperature. The correlation of the measurements with theoretical models supports the experimental methods that were developed. The knowledge of the printed silver layers assets and the optimization of the printing process lead to the design, fabrication and characterization of flexible electronics devices: a 17 GHz band-pass filter printed on polyimide, a flexible vacuum micro-sensor working on the Pirani principle, and a 250 µm thick membrane switch for keyboards. Finally, all printed RF capacitors were realized by stacking Barium Strontium Titanate (dielectric) and silver printed layers. These prototypes exhibit performances near the state-of-the-art and suggest new opportunities for printing technologies. This thesis offers a thorough study of inkjet printed silver layers and assess their potential for the manufacturing of flexible devices.