Electro-optically active organic diode with short protection
View Patent ↗An electro-optically active organic diode, for example an organic light emitting diode (OLED), comprises an anode electrode ( 102 ), a cathode electrode ( 122 ) and an electro-optically active organic layer ( 110 ) arranged in-between. A cover layer ( 124 ) is arranged in contact with a surface of the cathode layer ( 122 ) so that the cathode layer ( 122 ) is positioned between the organic layer ( 110 ) and the cover layer ( 124 ), which is formed of a substantially inert material with respect to a cathode layer ( 122 ) material in contact with said cover layer ( 124 ). The inert material is deposited on said surface of the cathode layer ( 122 ) so that the complete surface is covered and surface defects eliminated. A short protection layer ( 120 ) is further arranged between said cathode electrode ( 122 ) and said electro-optically active organic layer ( 110 ), and adjacent to said cathode electrode ( 122 ), and is formed of an inorganic semiconductor material. The cover layer ( 124 ) and the short protection layer ( 120 ) together reduce the risk of shorts to occur between the cathode ( 122 ) and the anode ( 102 ) and thus increase reliability of the electro-optically active organic diode.
1. An electro-optically active organic diode, comprising:
an anode electrode layer;
a cathode electrode layer;
an electro-optically active organic layer arranged between said electrode layers;
a cover layer arranged in contact with a surface of the cathode electrode layer so that the cathode electrode layer is positioned between the electro-optically active organic layer and the cover layer, said cover layer comprising a substantially inert material with respect to a cathode layer material in contact with said cover layer, said inert material being deposited on said surface of the cathode electrode layer, wherein the cover layer is conducting; and
a conducting short protection layer arranged between said cathode electrode layer and said electro-optically active organic layer, and adjacent to said cathode electrode layer, wherein said short protection layer comprises an inorganic semiconductor material and has a thickness of at least 200 Å.
2. The organic diode as claimed in claim 1 , wherein the inorganic semiconductor material has a higher melting temperature than the material of the cathode layer.
3. The organic diode as claimed in claim 1 , wherein the inorganic semiconductor material has a band gap greater than 2.7 eV.
4. The organic diode as claimed in claim 1 , wherein the inorganic semiconductor material has an electron affinity between 0.5 eV and 3.5 eV.
5. The organic diode as claimed in claim 1 , wherein the inorganic semiconductor material has a dielectric constant greater than 1.
6. The organic diode as claimed in claim 1 , wherein the inorganic semiconductor material comprises a chalcogenide or binary oxide of an alkali earth metal or lanthanide.
7. The organic diode as claimed in claim 1 , wherein the cover layer comprises a glue.
8. The organic diode as claimed in claim 1 , wherein the cover layer comprises a thin film packaging material.
9. The organic diode as claimed in claim 1 , further comprising a auxiliary cover layer arranged on the cover layer.
10. The organic diode as claimed in claim 1 , wherein the inorganic semiconductor material has a dielectric constant greater than 10.
11. The organic diode as claimed in claim 6 , wherein the inorganic semiconductor material comprises a BaO, BaSe, La 2 O 3 or Ce 2 O 3 .
12. The organic diode as claimed in claim 1 , wherein the cover layer comprises a silicon nitride (SiN), silicon carbide (SiC), silicon dioxide (SiO 2 ) or aluminum oxide (Al 2 O 3 ).
13. An electro-optically active organic diode, comprising:
an anode electrode layer;
a cathode electrode layer;
an electro-optically active organic layer arranged between said electrode layers;
a cover layer arranged in contact with a surface of the cathode electrode layer so that the cathode electrode layer is positioned between the electro-optically active organic layer and the cover layer, said cover layer comprising a substantially inert material with respect to a cathode layer material in contact with said cover layer, said inert material being deposited on said surface of the cathode electrode layer;
a auxiliary cover layer arranged on the cover layer; and
a conducting short protection layer arranged between said cathode electrode layer and said electro-optically active organic layer, and adjacent to said cathode electrode layer, wherein said short protection layer comprises an inorganic semiconductor material and has a thickness of at least 200 Å.
14. An electro-optically active organic diode, comprising:
an anode electrode layer;
a cathode electrode layer;
an electro-optically active organic layer arranged between said electrode layers;
a cover layer arranged in contact with a surface of the cathode electrode layer so that the cathode electrode layer is positioned between the electro-optically active organic layer and the cover layer, said cover layer comprising a substantially inert material with respect to a cathode layer material in contact with said cover layer, said inert material being deposited on said surface of the cathode electrode layer, wherein the cover layer includes a silicon nitride (SiN), silicon carbide (SiC), silicon dioxide(SiO 2 ) or aluminum oxide Al 2 O 3 ; and
a conducting short protection layer arranged between said cathode electrode layer and said electro-optically active organic layer, and adjacent to said cathode electrode layer, wherein said short protection layer comprises an inorganic semiconductor material and has a thickness of at least 200 Å.