Formulations and electronic devices
A formulation comprising at least one solvent and at least two different functional compounds of formula (I) A B] k (I) wherein A is a functional structural element, the structural element serving as host material, as a unit that has hole-injection and/or hole-transport properties, as a unit t at has electron-injection and/or electron-transport properties, as a unit which has light-emitting properties, or as a unit which improves the transfer from the singlet state to the triplet state of light-emitting compounds; B is a solubility-promoting structural element; and k is an integer in the range from 1 to 20; the molecular weight of the functional compound is at least 550 g/mol, and the solubility-promoting structural element B conforms to the general formula (L-I)
1. A formulation comprising at least one solvent and at least two different functional compounds of formula (I)
A B] k (I)
wherein
A is a functional structural element, the structural element serving as a host material, as a unit that has hole-injection and/or hole-transport properties, as a unit that has electron-injection and/or electron-transport properties, as a unit which has light-emitting properties, or as a unit which improves the transfer from the singlet state to the triplet state of light-emitting compounds;
B is a solubility-promoting structural element; and
k is an integer in the range from 1 to 20;
the molecular weight of the functional compound is at least 550 g/mol, and the solubility-promoting structural element B conforms to the general formula (L-I)
wherein
Ar 1 and Ar 2 are each, independently of one another, an optionally substituted aryl or heteroaryl group;
X is, in each case, independently of one another, N or CR 2 ; with the proviso that in each case at least one X is N;
R 1 and R 2 are each, independently of one another, hydrogen, a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 40 C atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 40 C atoms or is a silyl group or a substituted keto group having 1 to 40 C atoms, an alkoxycarbonyl group having 2 to 40 C atoms, an aryloxycarbonyl group having 7 to 40 C atoms, a cyano group —CN, a carbamoyl group —C(═O)NH 2 , a haloformyl group —C(═O)—X, wherein X is a halogen atom, a formyl group —C(═O)—H, an isocyano group, an isocyanate group, a thiocyanate group or a thioisocyanate group, a hydroxyl group, a nitro group, a CF 3 group, Cl, Br, F, a crosslinkable group or an optionally substituted aromatic or heteroaromatic ring system having 5 to 60 ring atoms, or an aryloxy or heteroaryloxy group having 5 to 60 ring atoms, or a combination of these systems, wherein one or more of the groups R 1 and/or R 2 optionally define a mono- or polycyclic, aliphatic or aromatic ring system with one another and/or with the ring to which the group R 1 is bonded; and
l is 0, 1, 2, 3 or 4;
the dashed bond indicates the bond to the functional structural element A.
2. The formulation of claim 1 , wherein the functional structural element A in formula (I) serves as host material.
3. The formulation of claim 1 , wherein the functional structural element A in formula (I) is a unit that has hole-injection and/or hole-transport properties.
4. The formulation of claim 1 , wherein the functional structural element A in formula (I) is a unit that has electron-injection and/or electron-transport properties.
5. The formulation of claim 1 , wherein the functional structural element A in formula (I) is a unit which has light-emitting properties.
6. The formulation of claim 1 , wherein the formulation comprises at least one functional compound in which the functional structural element A in formula (I) is a unit having phosphorescent properties.
7. The formulation of claim 6 , wherein the formulation comprises at least one functional compound in which the functional structural element A in formula (I) is a unit which includes at least one heavy atom having an atomic number of greater than 36.
8. The formulation of claim 1 , wherein the functional structural element A in formula (I) is a unit which improves the transfer from the singlet state to the triplet state of light-emitting compounds.
9. The formulation of claim 1 , wherein the formulation comprises at least one functional compound in which the functional structural element A in formula (I) is a unit which has light-emitting properties, and at least one functional compound in which the functional structural element A in formula (I) is a unit which can serve as host material.
10. The formulation of claim 1 , wherein the formulation comprises at least two functional compounds in which the functional structural element A in formula (I) is a unit which can serve as host material.
11. The formulation of claim 1 , wherein the formulation comprises at least one functional compound in which the functional structural element A in formula (I) is a unit which can serve as host material, where the functional structural element A has at least one nitrogen atom.
12. The formulation of claim 1 , wherein the formulation comprises at least one functional compound which comprises no solubility-promoting structural element B of the general formula (L-I).
13. The formulation of claim 1 , wherein the proportion of functional compounds in the formulation which comprise no solubility-promoting structural element B of the general formula (L-I) is at most 50% by weight, based on the total weight of the functional compounds.
14. The formulation of claim 1 , wherein the formulation comprises at least 80% by weight of aromatic or heteroaromatic solvent.
15. The formulation of claim 1 , wherein the index k in formula (I) is an integer greater than or equal to 2.
16. The formulation of claim 1 , wherein the molecular weight of the functional compound of the general formula (I) is at least 800 g/mol.
17. The formulation of claim 1 , wherein the functional compound of the general formula (I) has a glass-transition temperature of at least 70° C.
18. The formulation of claim 1 , wherein the weight ratio of structural element A to structural element B in formula (I) is in the range from 2:1 to 1:20.
19. An electronic device produced from the formulation of claim 1 .
20. The electronic device of claim 19 , wherein the at least two functional compounds of the general formula (I) is present in the device as hole-transport, hole-injection, emitter, electron-transport, electron-injection, charge-blocking and/or charge-generation layer.
21. The electronic device of claim 19 , wherein the electronic device is an organic electroluminescent device, a polymeric electroluminescent device, an organic integrated circuit, an organic field-effect transistor, an organic thin-film transistor, an organic light-emitting transistor, an organic solar cell, an organic optical detector, an organic photoreceptor, an organic field-quench device, a light-emitting electrochemical cell, or an organic laser diode.
22. A process for producing an electronic device comprising (1) applying the formulation of claim 1 to a substrate and (2) drying the applied formulation.
23. The formulation of claim 1 , wherein X is, in each case, N.