Organic electroluminescent device and production process thereof

1. An organic electroluminescent device consisting of the following, in order:

a transparent substrate;

a transparent anode layer;

a hole transportation layer consisting of an arylamine;

an organic structure consisting of at least one light-emissive layer or at least one light-emissive unit having at least one light-emissive layer;

a low resistance electron-transporting layer consisting of cesium and an organic compound;

an organometallic complex-containing layer including an organometallic complex compound containing at least one metal ion selected from the group consisting of an alkali metal ion, an alkaline earth metal ion and a rare earth metal ion;

a reducing reaction generating layer; and

a transparent cathode layer

wherein the reducing reaction generating layer is a layer produced by depositing aluminum on the organometallic complex-containing layer, thereby causing an oxidation-reduction reaction therebetween; and wherein the cathode consists of ITO.

2. The organic electroluminescent device according to claim 1 , wherein the cesium and the organic compound are mixed in a molar ratio range of from 1:10 to 10:1 in the low resistance electron-transporting layer.

3. The organic electroluminescent device according to claim 1 wherein the low resistance electron-transporting layer has a resistivity of not less than 1.0×10 2 Ωcm and less than 1.0×10 10 Ωcm.

4. The organic electroluminescent device according to claim 1 , wherein the organometallic complex containing layer consists of Liq and bathocuproine in a molar ratio of a range from 1:10 to 10:1.

5. The organic electroluminescent device according to claim 1 , wherein the aluminum is deposited as a layer via one of a resistive heating vapor deposition method, an electron beam vapor deposition method, and a laser beam vapor deposition method.

6. The organic electroluminescent device according to claim 1 , wherein the transparent cathode layer is formed with one of a resistive heating vapor deposition method, an electron beam vapor deposition method, and a laser beam vapor deposition method.

7. The organic electroluminescent device according to claim 1 , wherein the transparent cathode layer is formed as a layer with a sputtering method, and a sputtering apparatus used in the sputtering method is a facing target sputtering system which includes a pair of opposed targets disposed with a certain distance, a reflection electrode capable of reflecting electrons towards a front peripheral area of each target and a magnetic field generation medium capable of forming a parallel magnetic field in a neighborhood of the peripheral portion of each target, the magnetic field having a portion parallel to the peripheral portion of the target.

8. A production method of an organic electroluminescent device having an anode layer, consisting of the following steps, in order:

forming a hole transportation layer consisting of an arylamine, on the anode layer;

forming an organic structure, consisting of at least one light-emissive layer or at least one light-emissive unit having at least one light-emissive layer, on the hole transportation layer;

forming a low resistance electron-transporting layer consisting of a mixed layer of bathocuproine and cesium on the organic structure, by co-deposition of bathocuproine and cesium on the organic structure;

forming an organometallic complex-containing layer wherein the organometallic complex consists of Liq, by co-deposition of bathocuproine and Liq or by deposition of Liq, to form a layer having a thickness of about one hundred (100) angstrom;

forming a reducing reaction generating layer by vapor depositing aluminum on the organometallic complex-containing layer thereby causing an oxidation-reduction reaction between the aluminum and the lithium; and

forming a cathode layer on the reducing reaction generating layer,

wherein both of the anode layer and the cathode layer are transparent layers;

and wherein the cathode consists of ITO.

9. The organic electroluminescent device of claim 1 wherein the low resistance electron-transporting layer is formed by co-deposition of bathocuproine and cesium in a molar ratio of bathocuproine:cesium of about 4:1 up to a thickness of about 300 Å.

10. A production method of an organic electroluminescent device having a transparent anode layer, comprising:

forming adjacent the anode layer a hole transportation layer consisting of an arylamine;

forming adjacent the hole transportation layer an organic structure consisting of at least one light-emissive layer or at least one light-emissive unit having at least one light-emissive layer;

forming adjacent the organic structure, by co-deposition of bathocuproine and cesium in a molar ratio of bathocuproine:cesium of about 4:1 up to a thickness of about 300 Å, a low resistance electron-transporting layer arranged to also function as an electron injection layer;

forming adjacent the low resistance electron-transporting layer an organometallic complex-containing layer including an organometallic complex compound containing at least one metal ion selected from the group consisting of an alkali metal ion, an alkaline earth metal ion and a rare earth metal ion;

forming adjacent the organometallic complex-containing layer a reducing reaction generating layer; and

forming a transparent cathode layer on the reducing reaction generating layer;

wherein

the reducing reaction generating layer is formed from an oxidation-reduction reaction caused by depositing aluminum on said organometallic complex-containing layer and

the cathode layer is formed by depositing an electrically conducting compound onto the reducing reaction generating layer, using a sputtering method and

wherein the cathode consists of ITO.

11. The organic electroluminescent device according to claim 1 , wherein the reducing reaction generating layer is a light transmissive layer.

12. The organic electroluminescent device according to claim 1 wherein the organic structure consisting of at least one light-emissive layer or at least one light-emissive unit having a least one light-emissive layer consists of an Alq 3 light-emissive layer.

13. The organic electroluminescent device according to claim 1 consisting of the following, in order:

a transparent substrate;

a transparent anode layer;

an alpha-NPD hole transporting layer;

an Alq 3 light-emissive layer;

a BCP/Cs low resistance electron-transporting layer;

a BCP/Liq organometallic complex-containing layer;

a reducing reaction generating layer; and

an ITO cathode,

wherein the reducing reaction generating layer is produced by depositing aluminum on the organometallic complex-containing layer, thereby causing an oxidation-reduction reaction between the aluminum and the lithium ions of Liq of the organometallic complex-containing layer.

14. The production method of claim 10 which consists of:

forming adjacent the anode layer an alpha-NPD hole transporting layer,

forming adjacent the hole transporting layer an Alq 3 light-emissive layer,

forming adjacent the light-emissive layer, by co-deposition of bathocuproine and cesium in a molar ratio of bathocuproine:cesium of about 4:1 up to a thickness of about 300 Å, a low resistance electron-transporting layer,

forming adjacent the low resistance electron-transporting layer a BCP/Liq organometallic complex-containing layer,

forming adjacent the organometallic complex-containing layer, a reducing reaction generating layer; and

forming adjacent the reducing reaction generating layer an ITO cathode,

wherein the reducing reaction generating layer is produced by depositing aluminum on the organometallic complex-containing layer, thereby causing an oxidation-reduction reaction between the aluminum and the lithium ions of Liq of the organometallic complex-containing layer.