One of the main requirements to develop new microelectronics, micro-electromechanical systems (MEMS), liquid crystal displays (LCDs), thin film transistors (TFTs), micro-batteries, and especially for organic-light emitting devices (OLEDs) is to provide an efficient hermetic barrier against humidity. A hermetic barrier, for the electronic industry must have a Water Vapor Transmission Rate less than 10-4 g/m2/day. Hybrid organic-inorganic materials prepared by the sol-gel method provide good hermeticity. These materials have two mechanisms to prevent humidity penetration. The organic groups bonded to the inorganic network increase the hydrophobicity of the surface to repel water and block the porosity, to reduce the specific surface. To meet these requirements, a new class of gels was developed, organic modified silica gels that melt at low temperatures. These gels were prepared using Methyltriethoxysilane (MTES) and Dimethyldiethoxysilane (DMDES). Thick films were deposited on a strip of lithium either on glass or on mica. The film was applied by pouring, followed by a thermal treatment at low temperature. The reactivity of the lithium under the hybrid layer was observed to assess the performance of the hermetic barrier. The structural characteristics of the film were investigated using attenuated total reflection FT-IR and Raman spectroscopy, and field-emission scanning electron microscopy. The hydrophobicity was estimated by contact angle measurements.