SUBSTRATE FOR ORGANIC LIGHT-EMITTING DEVICE, AND ALSO ORGANIC LIGHT-EMITTING DEVICE INCORPORATING IT

• US 20110037379A1
• Filed: 12/23/2008
• Published: 02/17/2011
• Est. Priority Date: 12/27/2007
• Status: Active Grant

• Current Assignee: Saint-Gobain Glass France (Compagnie De Saint-Gobain)
• Original Assignee: Saint-Gobain Glass France (Compagnie De Saint-Gobain)
• Inventors: Vermersch, Julien, Giassi, Alessandro, Gerardin, Hadia, Lecamp, Guillaume, Tchakarov, Svetoslav
• Granted Patent: US 8,786,176 B2
• Time in Patent Office: Days
• US Class Current: 313/503
• CPC Class Codes: H10K 50/125 specially adapted for multicolour light emission, e.g. for emitting white light
• CPC Class Codes: H10K 50/816 Multilayers, e.g. transparent multilayers
• CPC Class Codes: H10K 50/852 comprising a resonant cavity structure, e.g. Bragg reflector pair
• CPC Class Codes: H10K 50/86 Arrangements for improving contrast, e.g. preventing reflection of ambient light

Abstract

A substrate for an organic light-emitting device, includes a transparent substrate having an optical index n0, bearing, on a first main face, a first transparent or semi-transparent coating of an electrode, referred to as the lower electrode, with a sheet resistance less than or equal to 6Ω/□ and which includes the following stack of layers: an anti-reflection sublayer having a given optical thickness L1 and having an optical index n1 such that the ratio of n1 to n0 is greater than or equal to 6/5; a first metallic layer having a given thickness e1; a first separating layer, having a given optical thickness L2; a second metallic layer, having an intrinsic electrical conductivity property, and having a given thickness e2; and an overlayer for adapting the work function, L1 being between 20 nm and 120 nm, L2 between 75 nm and 200 nm, and the sum of the thicknesses e1+e2 of the first and second metallic layers being less than or equal to 40 nm.

Claims

1. A substrate for an organic light-emitting device, comprising a transparent substrate having an optical index n0, bearing, on a first main face, a first transparent or semi-transparent coating of an electrode, referred to as the lower electrode, and which comprises the following stack of layers:

an anti-reflection sublayer having a given optical thickness L1 and having an optical index n1 such that the ratio of n1 to n0 is greater than or equal to 6/5;

a first metallic layer having a given thickness e1, positioned on the anti-reflection sublayer;

an overlayer for adapting the work function, having a given thickness e3, positioned on the first metallic layer;

a first separating layer, having a given optical thickness L2, positioned on the first metallic layer and beneath the overlayer;

a second metallic layer, having an intrinsic electrical conductivity property, and having a given thickness e2, said second layer being positioned between the first separating layer and the overlayer;

wherein L1 is between 20 nm and 120 nm, L2 is between 75 nm and 200 nm, and the sum of the thicknesses e1+e2 of the first and second metallic layers is less than or equal to 40 nm;

and wherein the lower electrode has a sheet resistance less than or equal to 6Ω

/□

.

2. The substrate according to claim 1, wherein L1 is less than or equal to 100 nm, preferably less than or equal to 80 nm and/or L2 is less than or equal to 160 nm, preferably 130 nm.

3. The substrate according to claim 1, wherein L1 is less than L2.

4. The substrate according to claim 1, wherein the first and second metallic layers are based on silver, the thickness e1 of the first metallic layer less than or equal to 15 nm and/or the thickness e2 of the second metallic layer is less than or equal to 15 nm, and, preferably, the thickness e1 is greater than the thickness e2.

5. The substrate according to claim 1, wherein the lower electrode has a sheet resistance less than or equal to 3Ω

/□

.

6. The substrate according to claim 1, wherein the anti-reflection sublayer comprises a base layer having a thickness greater than or equal to 3 nm that forms a barrier to alkali metals and/or an etch-stop layer, the base layer preferably substantially covering said main face of the substrate and being made of an optionally doped material based on silicon nitride, silicon oxycarbide, silicon oxynitride or silicon oxycarbonitride.

7. The substrate according to claim 1, wherein the anti-reflection sublayer comprises a layer, referred to as a first contact layer, based on a metal oxide and/or metal nitride, subjacent to the first metallic layer and/or the first separating layer comprises a layer, referred to as a second contact layer, based on a metal oxide and/or metal nitride, subjacent to the second metallic layer.

8. The substrate according to claim 7, wherein the first and/or the second contact layer is based on at least one of the following metal oxides, optionally doped:

chromium oxide, indium oxide, zinc oxide optionally sub-stoichiometric, aluminium oxide, titanium oxide, molybdenum oxide, zirconium oxide, antimony oxide, tin oxide, tantalum oxide or silicon oxide and wherein the first and/or the second contact layer preferably has a thickness greater than or equal to 3 nm.

9. The substrate according to claim 7, wherein the first and/or the second contact layer is based on doped or undoped zinc oxide.

10. The substrate according to claim 7, wherein the anti-reflection sublayer comprises a first non-crystalline smoothing layer made of a single or mixed oxide, said smoothing layer being positioned immediately beneath said first contact layer, and being made of a material other than that of the first contact layer, and preferably directly onto the substrate.

11. The substrate according to claim 7, wherein the first separating layer comprises a second non-crystalline smoothing layer made of a single or mixed oxide, said second smoothing layer being positioned immediately beneath said second contact layer and being made of a material other than that of the second contact layer.

12. The substrate according to claim 10, wherein the first and/or the second smoothing layer is a layer based on a single or mixed oxide, based on one or more of the following metals:

Sn, Si, Ti, Zr, Hf, Zn, Ga, In and in particular is a mixed oxide layer based on zinc and tin Sn_xZn_yO_z or a mixed indium tin oxide (ITO) layer or a mixed indium zinc oxide (IZO) layer.

13. The substrate according to claim 10, wherein at least 60% of the geometric thickness of the sublayer is made up of the first smoothing layer and/or at least 60% of the geometric thickness of the first separating layer is made up of the second smoothing layer.

14. The substrate according to claim 10, wherein the first smoothing layer is a layer based on an oxide that is non-stoichiometric in oxygen and is based on zinc and tin Sn_xZn_yO_z and optionally doped, preferably directly on the substrate, and the first contact layer is a layer based on a doped or undoped oxide that is non-stoichiometric in oxygen and is based on zinc ZnO, and/or the second smoothing layer is a layer based on an oxide that is non-stoichiometric in oxygen and is based on zinc and tin Sn_xZn_yO_z and optionally doped, and the second contact layer is a layer based on a doped or undoped oxide that is non-stoichiometric in oxygen and is based on zinc ZnO.

15. The substrate according to claim 10, wherein the first separating layer comprises, beneath the second contact layer and beneath the optional second smoothing layer, an additional layer of metal oxide such as zinc oxide, tin oxide, and/or an additional layer based on silicon nitride.

16. The substrate according to claim 1, wherein the first separating layer is composed of layer(s) having an electrical resistivity less than 10⁷ ohm·

cm, preferably less than or equal to 10⁶ ohm·

cm and/or the anti-reflection sublayer is composed of layer(s) having an electrical resistivity less than 10⁷ ohm·

cm, preferably less than or equal to 10⁶ ohm·

cm.

17. The substrate according to claim 1, wherein the overlayer is based on a single or mixed oxide, based on at least one of the following metal oxides, optionally doped:

chromium oxide, indium oxide, zinc oxide optionally sub-stoichiometric, aluminium oxide, titanium oxide, molybdenum oxide, zirconium oxide, antimony oxide, tin oxide, tantalum oxide or silicon oxide and preferably ITO, IZO, Sn_xZn_yO_z, and wherein the overlayer preferably has a thickness e3 less than or equal to 40 nm and/or wherein the overlayer is based on a thin metallic layer, in particular based on nickel, platinum or palladium, and is associated with a subjacent spacer layer made of a single or mixed metal oxide.

18. The substrate according to claim 1, wherein the first metallic layer is positioned directly on at least one first subjacent underblocking coating and/or is directly beneath at least one first superjacent overblocking coating, and/or the second metallic layer is positioned directly on at least one second subjacent underblocking coating and/or is directly beneath at least one second superjacent overblocking coating, and wherein at least one first or second overblocking or underblocking coating comprises a metallic, metal nitride and/or oxide layer, based on at least one of the following metals:

Ti, V, Mn, Fe, Co, Cu, Zn, Zr, Hf, Al, Nb, Ni, Cr, Mo, Ta, W, or based on an alloy of at least one of said materials, preferably based on Ni, or Ti, based on an alloy of Ni, or based on an alloy of NiCr.

19. The substrate according to claim 1, wherein the total thickness of indium-containing material in the lower electrode is less than or equal to 60 nm, preferably 50 nm.

20. The substrate according to claim 1, comprising an OLED system, having a thickness between 90 and 350 nm and located on top of the lower electrode that has electrode surface area(s) with a size greater than or equal to 1×

1 cm².

21. The substrate according to claim 20, comprising an upper electrode on top of said OLED system.

22. A method comprising providing a substrate according to claim 1, for forming an OLED device that forms an illumination or backlighting panel, in particular with a lower electrode that has electrode surface area(s) with a size greater than or equal to 1×

1 cm².

24. An organic light-emitting device incorporating a substrate according to claim 1 and an OLED system, on top of the lower electrode and that emits a polychromatic radiation defined at 0°

by coordinates (x1, y1) in the CIE XYZ 1931 chromaticity diagram.

30. The substrate according to claim 2, wherein L1 is less than L2.

31. The substrate according to claim 10, wherein the first and/or the second contact layer is based on doped or undoped zinc oxide.

32. The substrate according to claim 11, wherein the first and/or the second contact layer is based on doped or undoped zinc oxide.

33. The organic light-emitting device according to claim 24, wherein said device emits as the output a spectrum defined at 0°

by its colorimetric coordinates (x2, y2) in the CIE XYZ 1931 chromaticity diagram, such that √

{square root over (((x1−

x2)²+(y1−

y2)²))}{square root over (((x1−

x2)²+(y1−

y2)²))} is less than 0.1.

34. The organic light-emitting device according to claim 24, wherein said device emits as the output a spectrum defined at 0°

by its colorimetric coordinates (x2, y2) in the CIE XYZ 1931 chromaticity diagram and wherein the path length, in the CIE XYZ 1931 chromaticity diagram, between the spectrum emitted at 0° and

the spectrum emitted at 60°

, is less than or equal to 0.1.

35. The organic light-emitting device according to claim 24, wherein the path length, in the CIE XYZ 1931 chromaticity diagram, between the spectrum emitted at 0°

and the spectrum emitted at 60°

, is less than or equal to 0.05.

23. An organic light-emitting device incorporating a substrate bearing a lower electrode that comprises a stack successively composed of:

an anti-reflection sublayer having a given optical thickness L1 and having an optical index n1 such that the ratio of n1 to n0 is greater than or equal to 6/5;

a first metallic layer having a given thickness e1, positioned on the anti-reflection sublayer;

a first separating layer, having a given optical thickness L2, positioned on the first metallic layer;

a second metallic layer;

having an intrinsic electrical conductivity property, and having a given thickness e2, said second layer being positioned between the first separating layer and the overlayer;

an overlayer for adapting the work function, having a given thickness e3, positioned on the first metallic layer,

the sum of the thicknesses e1+e2 of the first and second metallic layers being less than or equal to 40 nm;

an OLED system, on top of the lower electrode and that emits a polychromatic radiation defined at 0°

by coordinates (x1, y1) in the CIE XYZ 1931 chromaticity diagram,

L1 and L2 being adjusted so that microcavities are formed with the first and second metallic layers, which microcavities resonate at two different wavelengths in the visible region that are sufficiently spaced apart, in particular by at least 100 nm, to broaden the resonance peaks and form a broadband spectrum in the visible region.

25. The organic light-emitting device according to claim 23, wherein said device emits as the output a spectrum defined at 0°

by its colorimetric coordinates (x2, y2) in the CIE XYZ 1931 chromaticity diagram, such that √

{square root over (((x1−

x2)²+(y1−

y2)²))}{square root over (((x1−

x2)²+(y1−

y2)²))} is less than 0.1.

26. The organic light-emitting device according to claim 23, wherein said device emits as the output a spectrum defined at 0°

by its colorimetric coordinates (x2, y2) in the CIE XYZ 1931 chromaticity diagram and wherein the path length, in the CIE XYZ 1931 chromaticity diagram, between the spectrum emitted at 0° and

the spectrum emitted at 60°

, is less than or equal to 0.1.

27. The organic light-emitting device according to claim 23, wherein the path length, in the CIE XYZ 1931 chromaticity diagram, between the spectrum emitted at 0°

and the spectrum emitted at 60°

, is less than or equal to 0.05.

28. The organic light-emitting device according to claim 23, wherein said device forms one or more transparent and/or reflective luminous surfaces, especially an illuminating, decorative or architectural system, or an indicating display panel, for example of the drawing, logo or alpha-numeric indication type, the system producing uniform light or differentiated luminous zones, especially differentiated by guided light extraction in the glass substrate.

29. The organic light-emitting device according to claim 23, wherein the organic light-emitting device is configured to be used:

for buildings, such as exterior luminous glazing, an internal luminous partition or a luminous glazed door (or part of a door), especially a sliding one;

for a transport vehicle, such as a luminous roof, a luminous side window (or part of a window), an internal luminous partition of a terrestrial, water-borne or airborne vehicle;

for urban or professional furniture, such as a bus shelter panel, a wall of a display counter or a shop window, a greenhouse wall, or an illuminating tile;

for interior furnishings, such as a shelf or cabinet element, a faç

ade of a cabinet, an illuminating tile, a ceiling, an illuminating refrigerator shelf, an aquarium wall;

for the backlighting of electronic equipment, especially a display screen, optionally a double screen, such as a television or computer screen, a touch screen; and

,

for an illuminating mirror, especially for lighting a bathroom wall or a kitchen work top, or for a ceiling.