Organic optoelectronic device and method for the encapsulation thereof

A method for the encapsulation of an organic optoelectronic device comprising the following successive steps:

• 1) providing a substrate,
• 2) depositing at least one electroluminescent unit on said substrate by a deposition of an internal electrode adjacent to said substrate, of an external electrode which is transparent or semi-transparent to the light emitted by said at least one electroluminescent unit and which defines an active light emission zone, and of a stack of organic films between said internal electrode and said external electrode, said stack comprising innermost said organic films, and
• 3) depositing a pre-encapsulation structure on said external electrode which comprises a buffer layer covering said external electrode and based on at least one heterocyclic organometallic complex with a glass transition temperature above 80° C., and a barrier layer covering said buffer layer and based on a silicon oxide with the formula SiOx, where x is a real number such that 0<x<2,
• 4) depositing a thin-layer encapsulation structure on said pre-encapsulation structure which comprises at least one inorganic layer which is placed on top of said at least one electroluminescent unit and encases it laterally,
• wherein step 3) comprises:
• a) depositing said buffer layer on said external electrode of said at least one electroluminescent unit,
• b) depositing said barrier layer by non-reactive thermal evaporation on said buffer layer, said barrier layer laterally coating said buffer layer,
• c) optionally transferring said at least one electroluminescent unit, covered for encapsulation with said buffer layer and said barrier layer, directly to the ambient atmosphere without being confined in a transfer enclosure such as a glove box, and
• d) subjecting to dry etching said at least one electroluminescent unit, covered with said buffer layer and said barrier layer, by means of an oxygen plasma or by reactive ion etching, to structure at least one of said innermost organic films to make it terminate laterally substantially at right angles to a peripheral edge of said barrier layer,
• and wherein step 4) comprises:
• e) depositing an inner said inorganic layer of said thin-layer encapsulation structure on said barrier layer by atomic layer deposition (ALD) or by plasma-assisted chemical vapor phase deposition (PECVD), said inner inorganic layer being based on at least one inorganic compound selected from the group consisting of compounds with the formulae AlxOy, SiOx, SixNy, SiOxNy, ZnSe, Sb2O3 and transparent conductive oxides (TCOs) optionally combined with a metal, in such a way that said inner inorganic layer extends from said substrate, thereby laterally coating said barrier layer and said innermost organic films of said stack of organic films.