Organic electroluminescent device and method of manufacturing the same
View Patent ↗An organic electroluminescent device (OELD) and a method of manufacturing the OELD are provided. The OELD includes a substrate, an anode electrode stacked on the substrate, an organic light emitting layer that is stacked on the anode electrode and has a plurality of protrusions on the organic light emitting layer, and a cathode electrode that covers the protrusions formed on the organic light emitting layer and is formed of a metal.
1. A method of manufacturing an organic electroluminescent device (OELD), the method comprising:
stacking an anode electrode on a substrate;
forming a base layer to a thickness by depositing an organic light emitting material on the anode electrode;
preparing a porous mask, in which a plurality of pores are formed through the porous mask, on the base layer;
forming a plurality of protrusions on an upper surface of the base layer by depositing an organic light emitting material through the plurality of pores of the porous mask positioned over the based layer;
removing the porous mask;
stacking a cathode electrode formed of a metal on the base layer and the plurality of protrusions to cover the plurality of protrusions, thereby to form a lower surface of the cathode electrode having a corrugated shape corresponding to the plurality of protrusions.
2. The method of claim 1 , wherein the plurality of protrusions are formed to have a pitch of 50 to 600 nm.
3. The method of claim 1 , wherein the plurality of protrusions are formed to have a height of 50 to 600 nm.
4. The method of claim 1 , wherein the porous mask is formed of an aluminium oxide.
5. The method of claim 1 , wherein the substrate is a transparent glass substrate or a plastic substrate.
6. The method of claim 1 , wherein the anode electrode is formed by depositing a transparent conductive material on the substrate.
7. The method of claim 1 , wherein the cathode electrode is formed by depositing a metal on the base layer and the plurality of protrusions to cover the plurality of protrusions.
8. The method of claim 4 , wherein the preparing the porous mask comprises:
preparing an aluminum substrate;
forming an aluminum oxide layer in which a plurality of pores are formed by anodizing a surface of the aluminium substrate; and
separating the aluminium oxide layer from the aluminium substrate.
9. The method of claim 8 , wherein the forming of the aluminium oxide layer comprises:
forming a first aluminium oxide layer in which a plurality of first pores are formed by firstly anodizing the surface of the aluminium substrate; and
forming a second aluminium oxide layer in which a plurality of second pores are formed by secondly anodizing the surface of the aluminium substrate after the first aluminium oxide layer is removed.
10. The method of claim 9 , wherein the transparent conductive material comprises indium tin oxide (ITO).