Organic EL lighting panel substrate, organic EL lighting panel, and organic EL lighting device

1. An organic EL lighting panel substrate comprising:

a light-transmitting substrate;

a transparent electrode, the transparent electrode being arranged on one surface of the light-transmitting substrate; and

an auxiliary electrode electrically connected to the transparent electrode,

wherein the light-transmitting substrate has a groove with a planar shape formed in a grid pattern,

the auxiliary electrode is arranged in said groove of the light-transmitting substrate, and

the auxiliary electrode is formed of a material having a volume resistivity at 20° C. in the range from 1.59×10 −8 to 13×10 −8 Ω·m.

2. The organic EL lighting panel substrate according to claim 1 , wherein the auxiliary electrode comprises at least one selected from the group consisting of copper, aluminum, silver, gold, molybdenum, tungsten, nickel, an aluminum-molybdenum alloy, an aluminum-neodymium alloy, and an aluminum-nickel alloy.

3. The organic EL lighting panel substrate according to claim 1 , wherein in the groove with the planar shape formed in the grid pattern of the light-transmitting substrate, the transparent electrode and the auxiliary electrode are arranged in this order from the light-transmitting substrate side.

4. The organic EL lighting panel substrate according to claim 3 , wherein the auxiliary electrode is arranged in such a manner that the height of a surface of the transparent electrode excluding a groove is substantially the same as the height of a surface of the auxiliary electrode.

5. The organic EL lighting panel substrate according to claim 1 , wherein in the auxiliary electrode, portions electrically connected to the transparent electrode comprise side surfaces of the auxiliary electrode.

6. The organic EL lighting panel substrate according to claim 1 , further comprising an insulating member, wherein the auxiliary electrode is coated with the insulating member.

7. The organic EL lighting panel substrate according to claim 1 , further comprising a reflective layer that reflects visible light, wherein the reflective layer is arranged between the transparent electrode and the auxiliary electrode.

8. The organic EL lighting panel substrate according to claim 1 , wherein the auxiliary electrode is arranged directly in the groove with the planar shape formed in the grid pattern of the light-transmitting substrate, and the transparent electrode is arranged on the auxiliary electrode.

9. The organic EL lighting panel substrate according to claim 1 , wherein the light-transmitting substrate has a multi-layered structure with a layer having a groove with the planar shape formed in the grid pattern being arranged on an outermost surface of a planar layer.

10. The organic EL lighting panel substrate according to claim 9 , wherein the layer having the groove with the planar shape formed in the grid pattern has a refractive index that is not lower than the refractive index of the planar layer and not higher than the refractive index of the transparent electrode.

11. The organic EL lighting panel substrate according to claim 9 , wherein the layer having the groove with the planar shape formed in the grid pattern has a refractive index in the range from 1.5 to 1.9.

12. The organic EL lighting panel substrate according to claim 1 , wherein the cross-sectional shape of the groove of the light-transmitting substrate is at least one of a polygonal shape and a semicircular shape.

13. An organic EL lighting panel comprising:

an organic EL lighting panel substrate;

an organic EL layer; and

a cathode layer,

wherein the organic EL lighting panel substrate is the organic EL lighting panel substrate according to claim 1 , and

the organic EL layer and the cathode layer are laminated on the transparent electrode in this order.

14. The organic EL lighting panel according to claim 13 , further comprising:

a power feed contact portion for an anode near an end of the transparent electrode; and

a power feed contact portion for a cathode near an end of the cathode layer,

wherein both the power feed contact portions are formed of the same material as the auxiliary electrode.

15. An organic EL lighting device comprising: the organic EL lighting panel according to claim 13 .

16. The organic EL lighting panel substrate according to claim 2 , wherein in the groove with the planar shape formed in the grid pattern of the light-transmitting substrate, the transparent electrode and the auxiliary electrode are arranged in this order from the light-transmitting substrate side.

17. The organic EL lighting panel substrate according to claim 2 , wherein in the auxiliary electrode, portions electrically connected to the transparent electrode comprise side surfaces of the auxiliary electrode.

18. The organic EL lighting panel substrate according to claim 3 , wherein in the auxiliary electrode, portions electrically connected to the transparent electrode comprise side surfaces of the auxiliary electrode.

19. The organic EL lighting panel substrate according to claim 4 , wherein in the auxiliary electrode, portions electrically connected to the transparent electrode comprise side surfaces of the auxiliary electrode.

20. The organic EL lighting panel substrate according to claim 2 , further comprising an insulating member, wherein the auxiliary electrode is coated with the insulating member.