Light-emitting device with organic layer doped with photoluminescent material

• US 6,777,724 B2
• Filed: 11/15/2002
• Issued: 08/17/2004
• Est. Priority Date: 11/16/2000
• Status: Expired due to Term

• Current Assignee: BOE Technology Group Co., Ltd.
• Original Assignee: General Electric Company
• Inventors: Srivastava, Alok Mani, Duclos, Steven Jude, Duggal, Anil Raj
• Primary Examiner(s): Flynn, Nathan J.
• Assistant Examiner(s): FORDE, REMMON R
• Application Number:
  US10/298,202
• Publication Number:
  US 20030094626A1
• Time in Patent Office: 641 Days
• Field of Search: 257/184, 257/87, 257/89, 257/90, 257/96, 257/98, 257/100, 257/103, 257/40, 257/13, 313/501, 313/503, 313/506, 313/507
• US Class Current: 257/184
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H10K 19/901 Assemblies of multiple devices comprising at least one organic element specially adapted for rectifying, amplifying, oscillating or switching
• CPC Class Codes: H10K 2102/331 Nanoparticles used in non-emissive layers, e.g. in packaging layer
• CPC Class Codes: H10K 50/125 specially adapted for multicolour light emission, e.g. for emitting white light
• CPC Class Codes: H10K 50/14 Carrier transporting layers
• CPC Class Codes: H10K 50/17 Carrier injection layers
• CPC Class Codes: H10K 50/171 Electron injection layers
• CPC Class Codes: H10K 59/35 comprising red-green-blue [RGB] subpixels

Abstract

A light-emitting device includes an anode, a cathode, and at least one organic electroluminescent (“EL”) material positioned between the anode and the cathode. Nanoparticles of at least one photoluminescent material are dispersed in the organic EL material. The organic EL material emits a first electromagnetic (“EM”) radiation having a first spectrum in response to an applied electrical field. The PL material absorbs a portion of the first EM radiation emitted by the organic EL material and emits a second EM radiation having a second spectrum. A plurality of the light-emitting devices are arranged on a transparent substrate to provide a panel display or a lighting source.

Claims

1. A light-emitting device comprising:

an anode disposed on a substantially transparent substrate;

a hole injection enhancement material disposed on the anode and opposite the substrate;

a hole transport material disposed on the hole injection enhancement material and opposite the anode;

at least one organic EL material disposed on the hole transport material and opposite the hole injection enhancement material, the organic EL material having a plurality of nanoparticles of at least one inorganic PL material dispersed therein, the organic EL material emitting a first EM radiation having a first spectrum in response to an applied electrical voltage if the electrical voltage is applied through the anode and the cathode, and the inorganic PL material absorbing a portion of the first EM radiation having the first spectrum and emitting a second EM radiation having a second spectrum;

an electron injection enhancement and transport material disposed on the organic EL material and opposite the hole transport material; and

a cathode.

2. The light-emitting device of claim 1 further comprising at least an additional PL material dispersed in the hole injection enhancement material.

3. The light-emitting device of claim 1 further comprising at least an additional PL material dispersed in the hole transport material.

4. The light-emitting device of claim 1 further comprising at least an additional PL material dispersed in the electron injection enhancement and transport material.

5. The light-emitting device of claim 1 wherein

the substrate comprises a material selected from the group consisting of glass, quartz, polycarbonate, silicone, polyacrylate, and epoxy resin;

the anode is selected from the group consisting of indium tin oxide, tin oxide, indium oxide, zinc oxide, indium zinc oxide, and mixtures thereof;

the hole injection enhancement material is selected from the group consisting of 3,4,9,10-perylenetetra-carboxylic dianhydride, bis(1,2,5-thiadiazolo)-p-quinobis(1,3-dithiole), and mixtures thereof;

the hole transport material is selected from the group consisting of 3,4,9,10-perylenetetra-carboxylic dianhydride, bis(1,2,5-thiadiazolo)-p-quinobis(1,3-dithiole), and mixtures thereof;

the organic EL material comprises a material selected from the group consisting of poly(N-vinylcarbazole), poly(alkylfluorene), poly(paraphenylene), polysilane, 1,3,5-tris[N-(4-diphenylaminophenyl)phenylamino] benzene, anthracene, phenylanthracene, tetraarylethene, coumarin, rubrene, tetraphenylbutadiene, perylene, coronene, aluminum acetoacetonate, gallium acetoacetonate, indium acetoacetonate, scandium acetoacetonate, aluminum alkylphenoxide, gallium alkylphenoxide, indium alkylphenoxide, scandium alkylphenoxide, derivatives thereof, and mixtures thereof;

the inorganic PL material is selected from the group consisting of yttrium aluminum oxide garnet Y₃Al₅O₁₂;

(Y_1-x-yGd_xCe_y)₃Al₅O₁₂;

(Y_1-xCe_x)₃(Al_1-yGa_y)O₁₂;

(Y_1-x-yGd_xCe_y)(Al_5-zGa_z)O₁₂;

(Gd_1-xCe_x)Sc₂Al₃O₁₂;

wherein 0≦

x≦

1, 0≦

y≦

1, 0≦

z≦

5 and x+y≦

1;

Ca₈Mg(SiO₄)₄Cl₂;

Eu²⁺,Mn²⁺;

GdBO₃;

Ce³⁺, Tb³⁺;

CeMgAl₁₁O₁₉;

Tb³⁺;

Y₂SiO₅;

Ce³⁺,T³⁺;

BaMg₂Al₁₆O₂₇;

Eu²⁺,Mn²⁺;

Y₂O₃;

Bi³⁺,Eu³⁺;

Sr₂P₂O₇;

Eu²⁺,Mn²⁺;

SrMgP₂O₇;

Eu²⁺,Mn²⁺;

(Y,Gd)(V,B)O₄;

Eu³⁺;

3.5MgO.0.5MgF₂.GeO₂;

Mn⁴⁺;

BaMg₂Al₁₆O₂₇;

Eu²⁺; and

Sr₅(PO₄)₁₀Cl₂;

Eu²⁺;

the electron injection enhancement and transport material is selected from the group consisting of tris(8-quinolinolato)aluminum, oxadiazole derives, quinoline derivatives, quinoxaline derivatives, diphenylquinone derivatives, nitro-substituted fluorene derivatives, and mixtures thereof; and

the cathode is selected from the group consisting of K, Li, Na, Mg, La, Ce, Ca, Sr, Ba, Al, Ag, In, Sn, Zn, Zr, alloys thereof, and mixtures thereof.

6. The light-emitting device of claim 1 wherein

the substrate is made of glass;

the anode is made of indium tin oxide

the hole injection enhancement material is 3,4,9,10-perylenetetra-carboxylic dianhydride;

the hole transport material is 3,4,9,10-perylenetetra-carboxylic dianhydride;

the organic EL material is selected from the group consisting of poly(N-vinylcarbazole), poly(alkylfluorene), and polysilane;

the inorganic PL material is yttrium aluminum oxide garnet Y₃Al₅O₁₂;

the electron injection enhancement and transport material is tris(8- quinolinolato)aluminum; and

the cathode is an alloy of Al—

Mg.

8. A light-emitting panel display comprising a plurality of the light-emitting devices of claim 6, said plurality of light-emitting devices is attached to a substantially transparent panel.

14. A light source emitting white light comprising a plurality of the light-emitting devices of claim 6, wherein the light-emitting devices are arranged adjacently on a substantially transparent substrate such that two adjacent light-emitting devices emit two different colors selected from blue, green, and red.

7. A light-emitting panel display comprising a plurality of light-emitting devices, said plurality of light-emitting devices is attached to a substantially transparent panel, each of said light-emitting device comprising:

an anode;

a cathode; and

at least one organic EL material disposed between the anode and the cathode, the organic EL material having a plurality of nanoparticles of at least one inorganic PL material dispersed therein, the organic EL material being capable of emitting a first EM radiation having a first spectrum in response to an electrical voltage applied through the anode and the cathode, and the PL material being capable of absorbing a portion of the first EM radiation and emitting a second EM radiation having a second spectrum.

9. A light-emitting panel display comprising

a substantially transparent panel;

a common anode disposed on the panel;

a plurality of light-emitting objects disposed on the common anode and opposite the panel, each of the objects comprising at least one organic EL material having nanoparticles of at least one PL material dispersed therein, the organic EL material being capable of emitting a first EM radiation having a first spectrum in response to an applied electrical voltage, the PL material being capable of absorbing a portion of the first EM radiation and emitting a second EM radiation having a second spectrum; and

at least one cathode disposed on the organic EL material and opposite the anode.

10. The light-emitting panel display of claim 9 wherein

the panel comprises a material selected from the group consisting of glass, quartz, polycarbonate, silicone, polyacrylate, and epoxy resin;

the anode is selected from the group consisting of indium tin oxide, tin oxide, indium oxide, zinc oxide, indium zinc oxide, and mixtures thereof;

the organic EL material comprises a material selected from the group consisting of poly(N-vinylcarbazole) poly(alkylfluorene);

poly(paraphenylene) polysilane;

1,3,5-tris[N-(4-diphenylaminophenyl)phenylamino] benzene;

anthracene;

phenylanthracene tetraarylethene;

coumarin;

rubrene;

tetraphenylbutadiene perylene;

coronene;

aluminum acetoacetonate gallium acetoacetonate;

indium acetoacetonate;

scandium acetoacetonate;

aluminum alkylphenoxide;

gallium alkylphenoxide;

indium alkylphenoxide;

scandium alkylphenoxide;

derivatives thereof; and

mixtures thereof;

the PL material is selected from the group consisting of yttrium aluminum oxide garnet Y₃Al₅O₁₂;

(Y_1-x-yGd_xCe_y)₃Al₅O₁₂;

(Y_1-xCe_x)₃(Al_1-yGa_y)O₁₂;

(Y_1-x-yGd_xCe_y)(Al_5-zGa_z)O₁₂;

(Gd_1-xCe_x)Sc₂Al₃O₁₂, wherein 0≦

x≦

1, 0≦

y≦

1, 0≦

z≦

5 and x+y≦

1;

Ca₈Mg(SiO₄)₄Cl₂;

Eu²⁺,Mn²⁺;

GdBO₃;

Ce³⁺, Tb³⁺;

CeMgAl₁₁O₁₉;

Tb³⁺;

Y₂SiO₅;

Ce³⁺,T³⁺;

BaMg₂Al₁₆O₂₇;

Eu²⁺,Mn²⁺;

Y₂O₃;

Bi³⁺,Eu³⁺;

Sr₂P₂O₇;

Eu²⁺,Mn²⁺;

SrMgP₂O₇;

Eu²⁺,Mn²⁺;

(Y,Gd)(V,B)O₄;

Eu³⁺;

3.5MgO.0.5MgF₂.GeO₂;

Mn⁴⁺;

BaMg₂Al₁₆O₂₇;

Eu²⁺; and

Sr₅(PO₄)₁₀Cl₂;

Eu²⁺; and

the cathode is selected from the group consisting of K, Li, Na, Mg, La, Ce, Ca, Sr, Ba, Al, Ag, In, Sn, Zn, Zr, alloys thereof, and mixtures thereof.

11. The light-emitting panel display of claim 9 wherein

the substrate is made of glass;

the anode is made of indium tin oxide the organic EL material is selected from the group consisting of poly(N-vinylcarbazole), poly(alkylfluorene), and polysilane;

the PL is yttrium aluminum oxide garnet Y₃Al₅O₁₂; and

the cathode is an alloy of Al—

Mg.

12. The light-emitting panel display of claim 9 wherein each of said objects further comprising:

a hole injection enhancement material which is selected from the group consisting of 3,4,9,10-perylenetetra-carboxylic dianhydride, bis(1,2,5-thiadiazolo)-p-quinobis(1,3-dithiole), and mixtures thereof;

a hole transport material which is selected from the group consisting of 3,4,9,10-perylenetetra-carboxylic dianhydride, bis(1,2,5-thiadiazolo)-p-quinobis(1,3-dithiole), and mixtures thereof; and

an electron injection enhancement and transport material which is selected from the group consisting of tris(8-quinolinolato)aluminum, oxadiazole derives, quinoline derivatives, quinoxaline derivatives, diphenylquinone derivatives, nitro-substituted fluorene derivatives, and mixtures thereof.

13. A light source emitting white light comprising a plurality of light-emitting devices that are arranged adjacently on a substantially transparent substrate such that two adjacent light-emitting devices emit two different colors selected from blue, green, and red, wherein each of the light-emitting devices comprises:

an anode;

a cathode; and

at least one organic electroluminescent (“

EL”

) material disposed between the anode and the cathode, the organic EL material having a plurality of nanoparticles of at least one PL material dispersed therein, the organic EL material being capable of emitting a first EM radiation having a first spectrum in response to an electrical voltage applied through the anode and the cathode, and the PL material being capable of absorbing a portion of the first EM radiation and emitting a second EM radiation having a second spectrum.

15. The light source of claim 13, wherein the light-emitting devices are arranged in a matrix of rows and columns, and each row or column forms a periodic pattern of sets of adjacent blue, green, and red colors.