Polymer and organic light emitting device
A polymer comprising a repeat unit of formula (I): wherein R 1 in each occurrence is independently H or a substituent; R 2 in each occurrence is independently a substituent; and x is 0, 1, 2 or 3. The polymer may be used as a light-emitting polymer in an organic light-emitting device.
1. A polymer comprising a repeat unit of formula (I):
wherein R 1 in each occurrence is independently H or a substituent; R 2 in each occurrence is independently a substituent; and x is 0, 1, 2 or 3;
wherein the repeat unit of formula (I) is bound directly to aromatic carbon atoms of adjacent repeat units by carbon-carbon bonds between aromatic carbon atoms of the repeat unit of formula (I) and the aromatic carbon atoms of the adjacent repeat units.
2. A polymer according to claim 1 wherein each R 1 is independently a C 1-40 hydrocarbyl group.
3. A polymer according to claim 1 wherein each x is 0.
4. A polymer according to claim 1 wherein at least one x is at least 1.
5. A polymer according to claim 1 wherein each R 2 is independently a C 1-40 hydrocarbyl group.
6. A polymer according to claim 1 wherein the polymer is a copolymer comprising one or more co-repeat units.
7. A formulation comprising a polymer according to claim 1 and at least one solvent.
8. An organic light-emitting device comprising an anode, a cathode and a semiconducting region between the anode and the cathode wherein the semiconducting region comprises a polymer comprising a repeat unit of formula (I):
wherein R 1 in each occurrence is independently H or a substituent; R 2 in each occurrence is independently a substituent; and x is 0, 1, 2 or 3;
wherein the repeat unit of formula (I) is bound directly to aromatic carbon atoms of adjacent repeat units by carbon-carbon bonds between aromatic carbon atoms of the repeat unit of formula (I) and the aromatic carbon atoms of the adjacent repeat units.
9. An organic light-emitting device according to claim 8 wherein the semiconducting region comprises a light-emitting layer comprising the polymer.
10. An organic light-emitting device according to claim 8 wherein the semiconducting region comprises a light-emitting layer and a charge-transporting layer, the charge-transporting layer comprising the polymer.
11. An organic light-emitting device according to claim 8 wherein the device emits white light.
12. A method of forming a device according to claim 8 , the method comprising the steps of depositing a formulation comprising a polymer comprising a repeat unit of formula (I):
wherein R 1 in each occurrence is independently H or a substituent; R 2 in each occurrence is independently a substituent; x is 0, 1, 2 or 3; and at least one solvent and evaporating the at least one solvent.
13. A method for a use of a repeat unit of formula (I) to enhance the solubility of a polymer:
wherein R 1 in each occurrence is independently H or a substituent; R 2 in each occurrence is independently a substituent; and x is 0, 1, 2 or 3;
wherein the repeat unit of formula (I) is bound directly to aromatic carbon atoms of adjacent repeat units by carbon-carbon bonds between aromatic carbon atoms of the repeat unit of formula (I) and the aromatic carbon atoms of the adjacent repeat units.