Radiation-emitting organic-electronic device and method for producing a radiation-emitting organic-electronic device

1. A radiation-emitting organic electronic device comprising:

a substrate;

a first electrode disposed over the substrate; and

a light-emitting layer disposed over the first electrode, wherein the light-emitting layer comprises a fluorescent compound of the following formula A:

wherein R is an electron-withdrawing substituent,

wherein R′ is an electron-donating substituent,

wherein the spacer comprises a linear molecular chain with the substituents R and R′ bonded to ends and at least one E group bonded to the linear molecular chain, where E is hydrogen and/or an organic radical, and

wherein the linear molecular chain of molecules of the fluorescent compound is aligned parallel to a plane of extension of the substrate; and

a second electrode disposed over the light-emitting layer,

wherein R comprises an electron-withdrawing substituent selected from the group consisting of:

wherein R′ comprises an electron-donating substituent selected from the group consisting of:

wherein represents a bond of the substituents R and R′ to the spacer in the compound of the formula A,

wherein R″=H, Alkyl, OH, OAlkyl, SH, SAlkyl or Hal,

wherein Alkyl=CH 3 , C 2 H 5 , CH(CH 3 ) 2 or CH 2 CH 2 CH 3 ,

wherein Hal=F, Cl, Br or I, and

wherein the fluorescent compound comprises a compound selected from the group consisting of a compound of the general formula 1:

a compound of the general formula 2:

a compound of the general formula 3:

a compound of the general formula 4:

a compound of the general formula 5:

a compound of the general formula 6:

a compound of the general formula 7:

a compound of the general formula 8:

a compound of the general formula 9:

a compound of the general formula 10:

a compound of the general formula 11:

a compound of the general formula 12:

 and

a compound of the general formula 13:

where

X, X′, Z and Z′ are the same or different and are each independently C—H or N,

L and L′ are each NH, O or S,

n, n′, n″, n′″, m, m′″, q=1, 2, 3 or 4,

m′, m″, p″=4, 5, 6, 7, 8 or 9, and

p, p′, q′=3, 4, 5, 6 or 7, and where aromatic systems in the compounds of the formulae 1 to 13 are replaceable wholly or partly by five- or six-membered heteroaromatic systems.

2. The device according to claim 1 , wherein, during operation of the device, each molecule of the fluorescent compound is able to have a singlet ground state S O , an excited singlet state S 1 populated by a singlet exciton and a triplet state T 1 excited by triplet excitons, and a transition of the singlet exciton from the state S 1 to the singlet ground state S O is able to result in emission of radiation, wherein a transition dipole moment of the transition of the singlet exciton from the state S 1 to the ground state S O in the molecules of the fluorescent compound in the light-emitting layer is aligned parallel to the plane of extension of the substrate.

3. The device according to claim 2 , wherein an energy difference between the state S 1 and the state T 1 is between 0.01 eV and 0.25 eV.

4. The device according to claim 1 , wherein the linear molecular chain has the aromatic systems, the heteroaromatic systems and/or CC double bonds.

5. The device according to claim 1 , wherein the molecules of the fluorescent compound of the formula A, in a ground state, have a permanent dipole moment arranged parallel to the plane of extension of the substrate.

6. The device according to claim 1 , wherein the substituents on CC double bonds in the compounds of the formulae 1 to 5, 7 to 9 and 13 are arranged trans to one another.

7. The device according to claim 1 , wherein the light-emitting layer comprises a matrix material with the fluorescent compound present therein.

8. The device according to claim 7 , wherein the light-emitting layer consists essentially of the fluorescent compound and the matrix material.

9. The device according to claim 1 , wherein, during operation of the device, singlet and triplet excitons are formed in the light-emitting layer and more than 25% of the singlet and triplet excitons formed are utilized for emission of radiation.

10. The device according to claim 1 , wherein the first electrode or the second electrode comprises a metallic material.

11. The device according to claim 1 , further comprising a first charge carrier injection layer disposed between the first electrode and the light-emitting layer.

12. The device according to claim 11 , further comprising a second charge carrier injection layer disposed between the light-emitting layer and the second electrode.

13. The device according to claim 1 , further comprising a second charge carrier injection layer disposed between the light-emitting layer and the second electrode.

14. The device according to claim 1 , wherein a distance between the light-emitting layer and the first or second electrode is between 40 and 90 nm.

15. The device according to claim 1 ,

wherein during operation of the device, each molecule of the fluorescent compound is able to have a singlet ground state S O , an excited singlet state S 1 populated by a singlet exciton and a triplet state T 1 excited by triplet excitons, and a transition of the singlet exciton from the state S 1 to the singlet ground state S O is able to result in emission of radiation, wherein a transition dipole moment of the transition of the singlet exciton from the state S 1 to the ground state S O in the molecules of the fluorescent compound in the light-emitting layer is aligned parallel to the plane of extension of the substrate, and

wherein an energy difference between the state S 1 and the state T 1 is between 0.01 eV and 0.25 eV.

16. A radiation-emitting organic electronic device comprising:

a substrate;

a first electrode disposed over the substrate;

a light-emitting layer disposed over the first electrode,

wherein the light-emitting layer comprises a fluorescent compound of the following formula A:

wherein R comprises an electron-withdrawing substituent selected from the group consisting of:

wherein R′ comprises an electron-donating substituent selected from the group consisting of:

wherein represent a bond of the substituents R and R′ to the spacer in the compound of the formula A,

wherein R″=H, Alkyl, OH, OAlkyl, SH, SAlkyl or Hal,

Alkyl=CH 3 , C 2 H 5 , CH(CH 3 ) 2 or CH 2 CH 2 CH 3 and

Hal=F, Cl, Br or I,

wherein the spacer comprises a linear molecular chain with the two substituents R and R′ bonded to ends and at least one E group bonded to the linear molecular chain, where E is hydrogen and/or an organic radical, and

wherein the linear molecular chain of molecules of the fluorescent compound is aligned parallel to a plane of extension of the substrate; and

a second electrode disposed over the light-emitting layer, wherein during operation of the device, each molecule of the fluorescent compound is able to have a singlet ground state S O , an excited singlet state S 1 populated by a singlet exciton and a triplet state T 1 excited by triplet excitons, and a transition of the singlet exciton from the state S 1 to the singlet ground state S O is able to result in emission of radiation, wherein a transition dipole moment of the transition of the singlet exciton from the state S 1 to the ground state S O in the molecules of the fluorescent compound in the light-emitting layer is aligned parallel to the plane of extension of the substrate,

wherein the fluorescent compound comprises a compound selected from the group consisting of a compound of the general formula 1:

a compound of the general formula 2:

a compound of the general formula 3:

a compound of the general formula 4:

a compound of the general formula 5:

a compound of the general formula 6:

a compound of the general formula 7:

a compound of the general formula 8:

a compound of the general formula 9:

a compound of the general formula 10:

a compound of the general formula 11:

a compound of the general formula 12:

 and

a compound of the general formula 13:

where

X, X′, Z and Z′ are the same or different and are each independently C—H or N,

L and L′ are each NH, O or S,

n, n′, n″, n′″, m, m′″, q=1, 2, 3 or 4,

m′, m″, p″=4, 5, 6, 7, 8 or 9, and

p, p′, q′=3, 4, 5, 6 or 7, and where aromatic systems in the compounds of the formulae 1 to 13 are replaceable wholly or partly by five- or six-membered heteroaromatic systems.