Highly efficient organic light-emitting device using substrate or electrode having nanosized half-spherical convex and method for preparing the same
The present invention provides a transparent substance formed with a plurality of continuous half-spherical convexes having a diameter of 25˜1,000 nm on its first main surface; an organic light-emitting device comprising a substrate, a first electrode, an organic material layer(s) and a second electrode, sequentially, characterized by having a plurality of continuous half-spherical convexes having a diameter of 25˜1,000 nm on the underside of the substrate that does not contact the first electrode and/or the upside of the second electrode that does not contact the organic material layer; and a method for preparing same using a porous aluminum oxide layer forming process.
1. A transparent substance wherein a plurality of continuous half-spherical convexes having a diameter of 200 to 800 nm are formed on a first main surface of the transparent substance.
2. The transparent substance according claim 1 , prepared by a method comprising the steps of:
a) dipping an aluminum substrate having at least one aluminum surface in an acid solution, and applying an oxidation voltage of 10-400 V to the aluminum substrate so as to form an aluminum oxide layer on one surface of the aluminum substrate, in such a manner that a plurality of continuous recesses are formed on the aluminum oxide layer, and a plurality of continuous recesses having a curvature in identical direction to that of the recesses on the aluminum oxide layer are formed on an interface between the aluminum oxide layer and the aluminum substrate;
b) removing the aluminum oxide layer from the aluminum substrate formed with the aluminum oxide layer thereon, thereby forming a plurality of continuous half-spherical recesses having a diameter of 200 to 800 nm on one surface of the aluminum substrate; and
c) forming a plurality of continuous half-spherical convexes, having a diameter of 200 to 800 nm, on the first main surface of a transparent substance by using the aluminum substrate formed with a plurality of continuous half-spherical recesses as a mold.
3. The transparent substance according to claim 1 , wherein the transparent substance consists of a polymer material having no less than 60% of transmittance in the range of visible ray.
4. The transparent substance according to claim 1 , wherein the transparent substance consists of at least one material selected from a group consisting of poly(dimethylsiloxane) (PDMS) and polymethylmethacrylate (PMMA).
5. The transparent substance according to claim 1 , applied to a device that requires the minimization of a total internal reflection condition.
6. The transparent substance according to claim 5 , wherein the device is an organic light-emitting device.
7. A method for preparing a transparent substance, wherein a plurality of continuous half-spherical convexes having a diameter of 25-1,000 nm are formed on a first main surface of the transparent substance, comprising the steps of:
a) dipping an aluminum substrate having at least one aluminum surface in an acid solution, and applying an oxidation voltage of 10-400 V to the aluminum substrate so as to form an aluminum oxide layer on one surface of the aluminum substrate, in such a manner that a plurality of continuous recesses are formed on the aluminum oxide layer, and a plurality of continuous recesses having a curvature in identical direction to that of the recesses on the aluminum oxide layer are formed on an interface between the aluminum oxide layer and the aluminum substrate;
b) removing the aluminum oxide layer from the aluminum substrate formed with the aluminum oxide layer thereon, thereby forming a plurality of continuous half-spherical recesses having a diameter of 25-1,000 nm on one surface of the aluminum substrate; and
c) forming a plurality of continuous half-spherical convexes, having a diameter of 25-1,000 nm, on the lust main surface of a transparent substance by using the aluminum substrate formed with a plurality of continuous half-spherical recesses as a mold.