Transparent diffusive oled substrate and method for producing such a substrate

The invention is drawn to a transparent diffusive OLED substrate comprising the following successive elements or layers: (a) a transparent flat substrate (1) made of mineral glass having a refractive index n 1 of between 1.48 and 1.58, (b) a monolayer of mineral particles (3) attached to one side of the substrate (1) by means of a low index mineral binder (2) having a refractive index n 2 of between 1.45 and 1.61, and (c) a high index layer (4) made of an enamel having a refractive index n 4 comprised between 1.82 and 2.10 covering the monolayer of mineral particles (3), the mineral particles (3) having a refractive index n 3 comprised between n 2 +0.08 and n 4 -0.08 and protruding from the low index mineral binder (2) so as to be directly in contact with the high index layer (4), thereby forming a first diffusive interface (Di 1 ) between the mineral particles (3) and the low index binder (2), and a second diffusive interface (Di 2 ) between the mineral particles (3) and the high index layer (4).