Method for fabricating a nanostructured substrate for oled and method for fabricating an oled

Method for fabricating a substrate comprising a nanostructured surface for an organic light emitting diode OLED, in which the following successive steps are carried out:

• a) a layer of an organic resin or of a low melting point mineral material is deposited on a planar surface of a substrate;
• b) the organic resin is heated to a temperature equal to or higher than its glass transition temperature Tg or its melting point, or the mineral material is heated to a temperature equal to or higher than its melting point, and the layer of liquid organic resin or mineral material is printed with a mould having a nanostructuration, whereby the layer of organic resin or mineral material is provided with a first nanostructuration matching the nanostructuration of the mould;
• c) the temperature of the organic resin or of the mineral material is lowered to a temperature at which it is solid;
• d) the mould is separated from the layer of organic resin or of mineral material joined to the substrate;
• characterized in that the method further comprises the following successive steps:
• e) the organic resin is heated to a temperature equal to or higher than its glass transition temperature Tg or its melting point, or the mineral material is heated to a temperature equal to or higher than its melting point, and the organic resin or the mineral material is maintained at this temperature for a time tR called annealing time, whereby the organic resin or the mineral material flows and the first nanostructuration of the layer of organic resin or of mineral material is modified to produce a second nanostructuration;
• f) the organic resin or the mineral material is cooled below its glass transition temperature or its melting point to solidify it;
• g) optionally, the solid organic resin or the solid mineral material is annealed.