JP6018052B2 - Organic light emitting materials, devices and methods - Google Patents

Description

  This application is based on British Patent Application No. 1010741.5 filed on June 25, 2010, British Patent Application No. 1010742.3 filed on June 25, 2010, and British Patent Application No. 1010745 filed on June 25, 2010. No. 6, British Patent Application No. 1010743.1 filed on June 25, 2010 and British Patent Application No. 1101642.5 filed on January 31, 2011. The contents of each of the applications forming the aforementioned priority are hereby incorporated by reference in their entirety.

  The present invention relates to an organic light emitting composition, a device containing the organic light emitting composition, a method for producing the device, and an organic compound for them.

  Electronic devices containing active organic materials for use in devices such as organic light emitting diodes, organic photovoltaic devices, organic photodetectors, organic transistors and memory array devices are gaining increasing attention. Devices comprising organic materials offer benefits such as low weight, low power consumption and flexibility.

  Furthermore, the use of soluble organic materials allows the use of solution processing, such as ink jet printing or spin coating, in the manufacture of devices.

  Common organic light emitting devices (“OLEDs”) are fabricated on glass or plastic substrates that are coated with a transparent anode such as indium tin oxide (“ITO”). A thin film layer of at least one electroluminescent organic material is disposed on the first electrode. Finally, a cathode is disposed on the layer of electroluminescent organic material. A charge transport layer, a charge injection layer, or a charge blocking layer can be disposed between the anode and the light emitting layer and / or between the cathode and the light emitting layer.

  During operation, holes are injected into the device through the anode and electrons are injected into the device through the cathode. Holes and electrons combine in the organic light emitting layer to form excitons, which are then attenuated and emit light.

In WO90 / 13148, the organic light emitting material is a conjugated polymer such as poly (phenylene vinylene). In US Pat. No. 4,539,507, organic light emitting materials are a class of materials known as low molecular weight materials such as tris- (8-hydroxyquinoline) aluminum (“Alq ₃ ”).

  These materials produce electroluminescence due to radiative decay of singlet excitons (fluorescence), but according to spin statistics, up to 75% of excitons are non-radiatively decayed triplet excitons, ie fluorescent It has been determined that for OLEDs, the quantum efficiency can be as low as 25%. For example, Chem. Phys. Lett. 1993, 210, 61, Nature (London), 2001, 409, 494, Synth. Met. 2002, 125, 55 and references thereof.

  The presence of triplet excitons that can have relatively long-lived triplet excited states can be detrimental to the lifetime of OLEDs as a result of triplet-triplet or triplet-singlet interaction. ("Lifetime" is used herein in the context of OLED lifetime, where the brightness of the OLED at a constant current is a selected percentage (eg, 10% or 50%) from the initial brightness value. Means the length of time it takes to decrease, and “lifetime” means the half-life of a triplet exciton as used herein in the context of the lifetime of a triplet excited state). US Patent Application No. 2007/145886 discloses an OLED comprising a triplet quenching material to prevent or reduce triplet and triplet or triplet and singlet interactions.

  US Pat. No. 5,210,029 discloses an electroluminescent device comprising a luminescent material comprising distyrylbenzene.

  US Patent Application No. 2005/208322 discloses an OLED comprising a light emitting layer with light emission from 4,4'-bis (2,2'diphenylvinyl) -1,1'-biphenyl (DPVBi).

  Polymer (Korea) 2002, 26 (4), pp. 543-550 discloses a polymer host blended with DPVBi as an emitter. OLEDs have great potential for display and lighting applications. However, there is still a need to improve the performance of these devices.

  The inventors have identified compounds that effectively accept and quench triplets in OLEDs.

  In a first aspect, the present invention provides a composition comprising an organic semiconductor material and a triplet acceptor material of formula (I) having a triplet energy level lower than the triplet energy level of the organic semiconductor material. .

In the formula, each Ar independently represents an optionally substituted aryl group or heteroaryl group, n is 1 to 3, m is 1 to 5 each time it appears, q is 0 or 1, each R ³ is independently selected from H or a substituent, and each R ⁴ is independently selected from H or a substituent, and when R ⁴ is not H, the same carbon R ⁴ and (Ar) _m bonded to an atom may be linked by a direct bond or a divalent group, and when R ³ is not H, R ³ (independently every occurrence) and (Ar ) _N may be linked by a direct bond or a divalent group, and when n or m is at least 2, adjacent Ar groups may be linked by a divalent group, provided that q = When 0, R ³ is not H but by a direct bond or a divalent group (Ar ) It is connected to _n .

  Optionally, the organic semiconductor material is selected from fluorescent light emitting materials, hole transport materials, electron transport materials, hole blocking materials and electron blocking materials.

  Optionally, the organic semiconductor material is a polymer, and optionally is a light emitting polymer that includes a fluorescent emission repeating unit.

  In an optional variation, the composition comprises a blend of an organic semiconductor material and a triplet receptive material.

  In another optional variation, the triplet receptive material is chemically bonded to the organic semiconductor material or, if present, to another component of the composition.

  Optionally, the triplet receptive material is bonded in the main chain of the polymer or as a side chain group or end group of the polymer.

  Optionally, q = 1.

Optionally, each R ³ is H.

Optionally, each R ⁴ is H or — (Ar) _m .

  Optionally, q = 0.

Optionally, R ³ is (Ar) _n .

  Optionally, n is 1 or 2.

Optionally, the divalent linking group connects either an adjacent Ar group ; R ⁴ and (Ar) _m ; or R ³ and (Ar) _n , wherein the divalent linking group is : (CR ⁵ R ⁶ ) _p -,-(SiR ⁵ R ⁶ ) _p- , O, NR ⁵ and PR ⁵ , wherein R ⁵ and R ⁶ are each independently selected from H or a substituent, p Is 1-5, preferably 1 or 2.

  Optionally, at least one Ar group, preferably all Ar groups, is phenyl.

Optionally, R ³ and / or R ⁴ is phenyl.

Optionally, q = 0, n = 1, R ³ is phenyl, and R ³ and (Ar) _n are linked by a direct bond.

Optionally, R ³ and (Ar) _n are linked to form an optionally substituted fluorene.

Optionally, R ⁵ and R ⁶ are each independently selected from H or a substituent, wherein the substituent is
Alkyl (one or more non-adjacent C atoms may be replaced with O, S, substituted N, C═O and —COO—, and one or more H atoms may be replaced with F; Or aryl, heteroaryl, arylalkyl or heteroarylalkyl, each optionally substituted with halogen, cyano or alkyl (one or more non-adjacent C atoms are O , S, substituted N, C═O and —COO— may be substituted))
Selected from the group consisting of

Optionally, at least one Ar group is halogen; cyano; alkyl (one or more non-adjacent C atoms may be replaced with O, S, substituted N, C═O and —COO—. ); And-(Ar ⁴ ) _z (Ar ⁴ is independently selected from optionally substituted aryl or heteroaryl each occurrence, and z is at least 1, optionally 1, 2 or 3 , and the case where z is greater than 1, the plurality of Ar4 group, are connected, it is substituted with at least one substituent that is selected from the can) to form a straight chain or branched chain of Ar ⁴ group . Optionally, at least one meta position of at least one terminal Ar group is substituted with at least one substituent.

  Optionally, the organic semiconductor material comprises an amine.

  Optionally, the organic semiconductor material is a polymer comprising amine repeat units.

  Optionally, the triplet receptive material is present in an amount of at least 0.05 mol% and optionally 0.1 mol% relative to the organic semiconductor material.

  In a second aspect, the present invention provides a solution comprising a solvent and the composition of the first aspect of the present invention.

  In a third aspect, the present invention provides an anode, a cathode, a light emitting layer between the anode and the cathode, and optionally one selected from a charge transport layer and a charge blocking layer between the anode and the cathode. Or an organic light emitting device, wherein at least one of the light emitting layer and one or more optional layers comprises the composition of the first aspect.

  In a fourth aspect, the present invention provides a method of forming the organic light emitting device of the third aspect, comprising depositing the composition of the second aspect and evaporating the solvent.

  In a fifth aspect, the present invention provides an optionally substituted formula (I) for accepting triplet excitons generated by an organic semiconductor material in a composition comprising a triplet accepting unit and a luminescent material. Provides the use of materials.

In the formula, Ar, n, m, q, R ³ and R ⁴ are as described above, and when R ⁴ is not H, R ⁴ and (Ar) _m are linked by a direct bond or a divalent group. And when R ³ is not H, R ³ and (Ar) _n may be linked by a direct bond or a divalent group, and when n or m is at least 2, adjacent Ar groups May be linked by a divalent group, provided that when q = 0, R ³ is not H but is linked to (Ar) _n .

  The material of the fifth aspect may be as described with respect to the first aspect of the invention and may be used as a triplet absorbing material in a composition comprising the organic semiconductor material described with respect to the first aspect. .

  Optionally, according to the fifth aspect, the composition comprises an organic semiconductor material and a physical mixture of the material of formula (I).

  Optionally, according to the fifth aspect, the material of formula (I) is chemically bonded to the organic semiconductor material.

  Optionally, according to the fifth aspect, the organic semiconductor material is a polymer and the material of formula (I) is bound in the main chain of the polymer or as a side chain group or end group of the polymer Are connected.

  Optionally, according to the fifth aspect, the material of formula (I) quenches triplet excitons generated by the organic semiconductor material.

  Optionally, according to the fifth aspect, the material of formula (I) mediates the triplet-triplet annihilation of triplet excitons transferred from the organic semiconductor material to the triplet accepting unit.

  In a sixth aspect, the present invention provides a luminescent composition comprising a polymer and a luminescent unit of formula (Ia).

In the formula, Ar, n, m, R ³ and R ⁴ are as described above. When n or m is at least 2, adjacent Ar groups may be linked by a divalent group.

  Optionally, according to the sixth aspect, the composition comprises a blend of a polymer and a material of formula (I).

  Optionally, according to the sixth aspect, the material of formula (I) is bound in the main chain of the polymer or as a side chain group or end group of the polymer.

  In a seventh aspect, the present invention provides an organic light emitting device comprising the light emitting composition of the sixth aspect.

  In an eighth aspect, the present invention provides a compound of formula (Ia).

Wherein Ar, n, m, R ³ and R ⁴ are as defined in any one of claims 1 and 6-13, and when n or m is at least 2, adjacent Ar The groups may be linked by a divalent group and at least one terminal aryl group is substituted with a solubilizing substituent.

  Optionally, according to the eighth aspect, the compound has a solubility of at least 10 mg / ml in toluene.

  Optionally, according to the eighth aspect, the at least one terminal aryl group is phenyl and the at least one solubilizing substituent is located at the meta position of the phenyl.

  Optionally, according to the eighth aspect, the compound has the formula (II).

In which at least one R ³ is linear or branched alkyl or alkoxy, preferably alkyl.

  In a ninth aspect, the present invention provides a compound of formula (VI), which is optionally substituted with one or more substituents.

In the formula, each Ar independently represents an aryl group or a heteroaryl group.

  Optionally, the material of the ninth aspect can be used as a triplet absorbing material in a composition comprising the organic semiconductor material described with respect to the first aspect.

Optionally, according to the ninth aspect, one or more substituents are each independently alkyl (one or more non-adjacent C atoms of the alkyl group are O, S, substituted N, C═O and —COO— may be substituted, and one or more H atoms of the alkyl group may be replaced with F), and — (Ar ⁴ ) _z (Ar ⁴ is Independently selected from optionally substituted aryl or heteroaryl, z is at least 1, optionally 1, 2 or 3, and when z is greater than 1, a plurality of Ar4 groups are linked And can form a straight or branched chain of the Ar ⁴ group.

  Optionally, according to the ninth aspect, each Ar is optionally substituted phenyl.

  In a tenth aspect, the present invention provides a polymer comprising a repeating unit comprising the compound of the ninth aspect.

  Optionally, according to the tenth aspect, the repeating unit comprises formula (VIIa) or (VIIb).

  Optionally, the compound of the ninth aspect is substituted with at least one substituent capable of participating in metal catalyzed cross coupling. Optionally, the substituent is selected from boronic acid and its esters, sulfonic acid esters, and halogen, preferably bromine or iodine. Optionally, the substituted compound has the formula (VIIIa) or (VIIIb).

Wherein each X independently represents at least one substituent that can participate in metal-catalyzed cross-coupling, and r is 1 or 2.

  In the eleventh aspect, the invention provides a polymer according to the tenth aspect, comprising polymerizing a compound of formula (VIIIa) (r is 2) or a compound of formula (VIIIb) in the presence of a metal catalyst. Provide a method of forming.

In a first aspect of the invention, it will be appreciated that the invention relates to a composition in which the triplet acceptor unit of formula (I) does not substantially emit light. Energy level of the excited singlet state of the luminescent material (S ¹⁾ is prevented from any substantial movement of singlet excitons from S ¹ energy level to the S ¹ level of the triplet-receiving material of a light-emitting material Therefore, it is lower than the energy level of the corresponding triplet accepting unit, and preferably lower than this energy level.

  In the case of the second embodiment of the present invention in which the unit of formula (I) is a luminescent material, the opposite is true.

  “Aryl” and “heteroaryl” as used herein include both fused and unfused aryl and heteroaryl groups, respectively.

A “triplet accepting unit” as used herein means a unit that can accept a triplet exciton from a light emitting unit. In order to function efficiently, the triplet accepting unit has an energy level T ¹ in the triplet excited state that is lower in energy than the energy level in the triplet excited state of the light emitting unit.

R ³ and R ⁴ bonded to the opposite end of the double bond in the compound of formula (I) are independently present in each case in a cis or trans configuration, as shown by the wavy bond of formula (I) can do.

1 is a schematic diagram of triplet quenching by a compound of formula (I). FIG. 1 is a schematic diagram of a first triplet-triplet annihilation mechanism comprising a compound of formula (I). FIG. It is a figure which shows the 2nd triplet-triplet annihilation mechanism containing the compound of a formula (I). 1 is a diagram illustrating an organic light emitting device according to an embodiment of the present invention. FIG. 5 shows the electroluminescence spectrum of an exemplary OLED of the present invention compared to the electroluminescence spectrum of a comparative device. FIG. 4 shows the lifetime of four exemplary OLEDs of the present invention compared to a comparative device. FIG. 6 shows current density versus voltage for an exemplary OLED of the present invention compared to a comparative device. FIG. 6 shows the external quantum efficiency versus voltage of an exemplary OLED of the present invention compared to a comparative device. FIG. 6 is a graph of external quantum efficiency versus voltage for an exemplary device and a comparative device. 2 is a graph showing the triplet density of an exemplary device and a comparative device. 2 is a time-resolved electroluminescence graph of an exemplary device. FIG. 6 is a graph of external quantum efficiency versus time for an exemplary device and a comparative device. 2 is an electroluminescence graph of two exemplary devices and a comparative device. 14 is a graph of current density versus voltage for the exemplary device of FIG. 13 and a comparative device. FIG. 15 is a graph of external quantum efficiency versus voltage for the exemplary devices of FIGS. 13 and 14 and a comparative device. FIG. 16 is a graph showing the lifetime of the exemplary devices of FIGS. 13, 14 and 15 and comparative devices. FIG. FIG. 4 shows a photoluminescence spectrum of an exemplary composition of the present invention.

  The invention is described in detail below with respect to the composition of (A) (compound of formula (I) is a triplet acceptor material) and the composition of (B) (compound of formula (I) is a luminescent material). .

A. Triplet acceptance by compounds of formula (I) We have identified several pathways that can cause decay of triplet excitons in order to reduce or eliminate decay due to pathways that lead to shortened lifetime of the device. . This includes a path where the triplet exciton decays non-radiatively by the quench process, and the triplet exciton annihilates triplet-triplet, providing better device efficiency compared to the non-radiative quenching path. Pathways that provide delayed fluorescence that can be included are included.

  Without being bound to any theory, the mechanism of triplet quenching and delayed fluorescence that may occur is described below.

Triplet Quench FIG. 1 shows a first energy transfer mechanism of an exemplary OLED. In order to avoid suspicion, the scale of energy levels including FIG. 1 is not described in this specification. FIG. 1 shows the energy transfer of an OLED in which a light emitting material having a singlet excited state energy level S _1E and a singlet ground state energy level S _0E is arranged. Singlet excitons having energy S _1E are attenuated by the fluorescence emission hv indicated by the solid line arrow between S _1E and S _0E in FIG. Triplet and triplet exciton interactions or triplet and singlet exciton interactions can create a “superexcited” state on the luminescent material. Without being bound by any theory, it is believed that the formation of these high energy “superexcited” states on the luminescent material can be detrimental to the operational lifetime of the material. However, providing a triplet acceptor unit having an excited triplet state energy level T _1A lower than T _1E allows the triplet exciton to be transferred to the triplet acceptor unit for quenching, This is an alternative to the radiation decay from T _1E to S _0E , which is the spin forbidden process indicated by the dotted line in FIG. The S ₁ and T ₁ levels can be measured from the fluorescence and phosphorescence spectra, respectively.

The triplet accepting unit has a singlet excited state energy level higher than the singlet excited state energy level S _1E in order to substantially or completely prevent the transfer of singlet excitons from S _1E to S _1A . _{Has the} position S _1A . Preferably, S _1A is at an energy at least kT higher than S _1E to prevent any substantial reverse movement of excitons. Similarly, T _1E is preferably at an energy at least kT higher than T _1A .

Triplet-triplet annihilation FIG. 2 shows a second energy transfer mechanism of an exemplary OLED.

According to this embodiment, the triplet-triplet annihilation (TTA) caused by the interaction between two triplet accepting units is a maximum of 2 × T _1A (T _1A is the triplet excited state of the triplet acceptor material). Resulting in a triplet-triplet annihilation type singlet exciton having an energy of 1). This singlet exciton formed on the first triplet accepting unit of the two triplet accepting units has an energy level _SnA that is at a higher energy than S _1A and S _1E , and therefore This singlet exciton can move to S _1A and then to S _1E , from which light hv can be emitted as delayed fluorescence. Triplet excitons on the second triplet accepting unit of the two triplet accepting units can decay to the ground state T _0A .

Initially, the triplet exciton formed at T _1E moves to T _1A . By providing a triplet acceptor material having an energy level T _1A lower than T _1E , rapid exciton transfer from T _1E to T _1A can occur. This movement is relatively rapid compared to the decay rate of triplet excitons from T _1E to S _0E , which is the spin forbidden process indicated by the dotted arrows in FIG. The energy gap between T _1E and T _1A is preferably greater than kT to avoid reverse exciton migration from T _1A to T _1E . Similarly, the energy gap between S _1A and S _1E is preferably greater than kT to avoid reverse exciton migration from S _1E to S _1A .

The decay path of triplet excitons on T _1A competing with triplet-triplet annihilation is the non-radiative (quenching) path to S _0A previously described with respect to FIG. Several measures can be taken to maximize the potential for TTA rather than attenuation to _SOA . In particular,
i) The triplet absorbing material can be selected such that the triplet excitons on T _1A have a relatively long lifetime τ _TA . The relatively long life, but also means that the rate of reduction of the S _0A is relatively slow, the probability of TTA is meant that relatively high.
ii) The concentration of the triplet absorbing material in the light emitting layer may be relatively high, for example greater than 1 mol%, such as in the range of 0.1-10 mol%, or in the range of 1-10 mol%.
iii) Two or more triplet receptive materials can be placed in close proximity, eg as described below for units of formula (II).

  Each of these measures can be used alone or in combination.

  FIG. 3 shows a third energy transfer mechanism of an exemplary OLED.

In this case, triplet-triplet annihilation occurs between triplet excitons with energy T _1A located on the triplet accepting unit and triplet excitons with energy T _1E located on the luminescent material. It will be understood that this results in a triplet-triplet annihilation singlet exciton (TTAS) having an energy of maximum T _1E + T _1A . The energy level S _nA of singlet excitons is higher than S _1E, energy level S _nA therefore, moves the energy to the S _1A, it can be moved from S _1A to S _1E, the light therefrom hv can be emitted as delayed fluorescence.

  By avoiding triplet quenching due to quench sites formed during OLED drive, the lifetime of the device can be improved. In addition, by utilizing a TTA that produces stable delayed fluorescence, compared to a device where all triplet excitons are quenched (as shown in FIG. 1) or OLED drive with delayed fluorescence intensity at an early stage. There is a potential for improved efficiency compared to devices that do not have triplet acceptor units that can subsequently decline sharply.

  The mechanism for quenching the triplet and two or all three of the aforementioned two TTA mechanisms occur within the same device, and the amount of delayed fluorescence from each of the two mechanisms of TTA depends on the concentration of the luminescent material, the triplet. It will be appreciated that it depends on factors such as the concentration of the accepting unit, and the lifetime of the excited state of the triplet exciton on the luminescent and triplet accepting units.

  The long lifetime of a triplet exciton present on a triplet acceptor unit is either due to the annihilation with a triplet exciton present on another triplet acceptor unit or the annihilation with a triplet exciton present on the luminescent material. Can serve to increase the likelihood that TTA will occur, but other measures can be used to further increase the probability of TTA.

  For example, triplet accepting units can be placed in close proximity, optionally separated by a spacer, to increase the probability of TTA.

  Alternatively or additionally, triplet accepting units can be placed at high concentrations to increase the probability of TTA.

  The triplet exciton transfer rate constant from the luminescent material to the triplet acceptor material can be selected to exceed the triplet exciton quench transfer rate constant.

  In addition to or as an alternative to using a triplet acceptor material in the light emitting layer of the OLED, the triplet acceptor material of formula (I) may be disposed in the OLED layer that transports or blocks charge. it can. For example, triplet excitons can be formed in or transferred to the hole transport layer and can cause decomposition of the hole transport material of the hole transport layer. The triplet acceptor material of formula (I) can be provided to the hole transport material to quench these triplet excitons. For illustrative purposes, a composition comprising a triplet acceptor material of formula (I) and a luminescent material is described in more detail below, which triplet acceptor material does not produce luminescence when used in an OLED. It can be similarly used in combination with a charge transport material (for example, a hole transport material or an electron transport material).

Triplet Receptor Material A triplet acceptor material may be a compound that is not chemically bonded to a luminescent material but is physically blended, and the luminescent composition may include one or more additional components, such as one Or a plurality of charge transport materials, in particular one or more hole transport materials or electron transport materials. Alternatively, the triplet acceptor material can be bound to the luminescent material or, if present, bound to any of the other components described above.

  When a triplet acceptor material is blended with a luminescent material, the triplet acceptor material is preferably substituted with a solubilizing group. Exemplary triplet acceptor compounds include compounds having the following general formula (II):

Wherein m is as described above, p is 1 to 5, preferably 1 or 2, and R ³ is independently H or a solubilizing substituent each time it appears, provided that at least 1 One R ³ is a solubilizing substituent. Preferred solubilizing substituents are linear or branched alkyl or alkoxy, preferably alkyl. Two specific examples of such compounds are shown below.

  Solubilizing substituents in the meta position of the terminal aryl group can be particularly advantageous to improve solubility.

  Adjacent aryl groups may be linked as shown in the examples below, and adjacent phenyl groups are linked to form a fluorene unit. The bridging carbon atom of the fluorene unit can be provided with substituents to adjust the solubility, glass transition temperature or other properties of the compound.

  In the previous example, each carbon atom of the double bond carries only one substituent. However, one or more of these carbon atoms carry two substituents as shown in the following compound 4,4′-bis (2,2′diphenylvinyl) -1,1′-biphenyl (DPVBi) can do.

  Exemplary triplet acceptor compounds have the following formula where q in formula (I) is 0:

The compound may optionally be substituted with one or more substituents such as the aforementioned substituent R ⁵ , in particular one or more solubilizing substituents such as alkyl.

  When the luminescent material is a polymer, the units of formula (I) may be provided in the form of repeating units in the polymer backbone, for example in the form of one of the optionally substituted repeating units shown below.

In the formula, ^* indicates a connecting point for connecting repeating units to form a polymer chain. Exemplary repeat units include the following:

Wherein ^*, linked repeating units indicates the point of attachment to the polymer chain, Ak is alkyl, in particular branched or C ₁ ~ ₁₀ alkyl straight. Particularly preferred alkyl groups are n-butyl, t-butyl, n-hexyl and n-octyl. R is H or a substituent, optionally alkyl, or optionally substituted aryl or heteroaryl, for example phenyl substituted with one or more alkyl groups.

Additionally or alternatively, the triplet acceptor material may be substituted with one or more aryl or heteroaryl groups, such as one or more phenyl groups. Multiple aryl groups or heteroaryl groups can be linked to form a straight or branched chain, such as a dendritic group, of an arylene group or heteroarylene group. Exemplary dendritic groups, include the following, each of one or more substituents, for example, be substituted with one or more C ₁ ~ ₂₀ alkyl or C ₁ ~ ₂₀ alkoxy group It's okay.

  The triplet acceptor unit is bonded into the main chain of the light emitting polymer by polymerizing a monomer containing the repeating unit shown above, which is substituted with a leaving group that can participate in a metal-catalyzed cross-coupling reaction. can do. Exemplary leaving groups include halogen and boronic acid groups or boronic ester groups for use in Suzuki or Yamamoto polymerization reactions. These reactions are described in more detail below.

  Alternatively or additionally, when the luminescent material is a polymer, the triplet accepting unit is optionally in the form of a polymer end group or in the form of a pendant group pendant from the polymer backbone, for example as shown below. It can be provided in the form of a substituted side chain or end group.

In the formula, ^* indicates a connecting point for connecting a triplet accepting side chain group or a terminal group to the polymer.

The side chain group or terminal group is a suitable leaving group capable of participating in a metal-catalyzed cross-coupling reaction such as halogen or boronic acid or boronic ester, to remove the compound substituted at ^* on the polymer. It can be formed by reacting with a leaving group.

Alternatively, the side chain groups can be incorporated into the light emitting polymer by providing the side chain groups as monomer substituents, as shown below.
PG-polymerizable unit-PG
｜
In the triplet accepting unit formula, PG represents a polymerizable group such as the aforementioned leaving group or a polymerizable double bond. A spacer group, such as an alkylene chain, can separate the polymerizable unit from the triplet accepting unit. Exemplary polymerizable units include optionally substituted arylenes such as polyfluorenes, particularly 2,7-linked 9,9 dialkyl polyfluorene or 2,7-linked 9,9 diaryl polyfluorene; polyspiro Fluorenes, especially 2,7-linked poly-9,9-spirofluorenes; polyindenofluorenes, especially 2,7-linked polyindenofluorenes; polyphenylenes, especially poly-1,4 substituted with alkyl or alkoxy -Phenylene is included. An exemplary monomer for forming a polymer comprising a triplet accepting side group has the formula:

In this example, the fluorene monomer is provided with two triplet accepting units, or alternatively the fluorene monomer may be substituted with only one triplet accepting unit at position 9 of the fluorene, It will be appreciated that the 9 position is H or a substituent such as R ^{1 as described} below.

  An exemplary end cap unit has the following formula:

As mentioned above, multiple triplet accepting units can be placed in close proximity to increase the possibility of TTA and delayed fluorescence. For example, such two units can be provided with an optionally substituted unit having the general formula (III).
TAU-Spacer-TAU
(III)
In the formula, “TAU” represents the triplet accepting unit of formula (I), and the spacer is a conjugated or non-conjugated spacer group. The spacer group separates the two triplet accepting TAU groups and preferably separates their electronic characteristics (eg HOMO and LUMO). Depending on the exact nature of the conjugation and orbital overlap, Sp can optionally include one or more arylene or heteroarylene groups such as substituted phenyl, biphenyl or fluorene. Alternatively, Sp can optionally include an unconjugated linking group, such as alkyl, or the linking of another molecule that does not provide a conjugation pathway between the TAU group and the TAU group.

  The unit of formula (II) may be a separate compound physically mixed with the luminescent material or may be bound to the luminescent material. When the luminescent material is a polymer, the unit of the formula (II) can be bonded as a repeating unit, a side chain group or a terminal group of the main chain as described above.

Alternatively or additionally, the triplet accepting unit may be an oligomer or polymer comprising a repeating structure of formula (IIb), or a component of the oligomer or polymer.
(TAU-spacer) _m
(IIb)
In the formula, m is at least 2. The oligomer or polymer can be mixed with the luminescent material or placed in the polymer backbone.

  Although the coupling of the triplet accepting unit and the light emitting polymer has been described above, it will be understood that the triplet accepting unit can also be coupled to any other component of the composition, if present.

  The LUMO level of the triplet accepting unit of formula (I) can be selected to provide an electron trap. For example, when a triplet accepting unit is used in combination with an electron transporting material or a light emitting material including electron transporting functionality, the triplet accepting unit is at least 0.1 eV from the LUMO level of the light emitting material or electron transporting material. It can have a low LUMO level. Exemplary electron transport materials include a chain of arylene repeat units, such as a chain of fluorene repeat units, as described in more detail below.

  The concentration of the triplet accepting unit of formula (I) is optionally at least 0.05 mol%, optionally 0.1 mol%, or at least 1 mol%, such as 0.1 to 10 mol% or 1 to 1 with respect to the luminescent material. It is in the range of 10 mol%. The higher the triplet receptive material concentration, the greater the potential for TTA. To increase the possibility of TTA, the lifetime of the excited triplet present on the triplet acceptor material is optionally at least 1 microsecond. The lifetime of a triplet exciton is its half-life, which is described in Handbook of Photochemistry, 2nd edition, Steven L Murov, Ian Carmichael and Gordon L Hug and its references, the contents of which are incorporated herein by reference. As described, it can be measured by flash photolysis to measure the lifetime of single molecule triplets.

  Triplet acceptor materials, unlike phosphorescent dopants, do not provide an energetically prone route for absorbed triplets to radiatively decay, resulting in triplet excitons absorbed by the triplet acceptor material. It will be understood that no energy is substantially lost from the triplet acceptor material in the form of light emission from the triplet acceptor material.

  The density of triplet excitons on a luminescent material, for example on the polymer backbone of a conjugated luminescent polymer, can be measured using absorption in a quasi-continuous oscillation (quasi-cw) excited state, as described in more detail below. it can.

  FIG. 4 shows the structure of an OLED according to an embodiment of the present invention. The OLED includes a transparent glass or plastic substrate 1, an anode 2, a cathode 4, and a light emitting layer 3 provided between the anode 2 and the cathode 4. Additional layers (not shown) such as a charge transport layer, charge injection layer or charge blocking layer can be located between the anode 2 and the cathode.

Organic Semiconductor Materials Suitable organic semiconductor materials, particularly charge transport materials and / or luminescent materials, include small molecules, polymer materials and dendrimer materials, and compositions thereof. Light emitting or charge transporting polymers suitable for use in layer 3 include poly (arylene vinylenes) such as poly (p-phenylene vinylene), and polyfluorenes, particularly 2,7-linked 9,9 dialkyl polyfluorenes or 2, Polyarylenes such as 7-linked 9,9 diarylpolyfluorenes; polyspirofluorenes, especially 2,7-linked poly-9,9-spirofluorenes; polyindenofluorenes, especially 2,7-linked polyindenofluorenes; polyphenylenes In particular, poly-1,4-phenylene substituted with alkyl or alkoxy is included. Such polymers are described, for example, in Adv. Mater. 2000, 12 (23) 1737-1750 and references therein.

  Suitable luminescent polymers may be luminescent homopolymers containing luminescent repeat units, or luminescent repeat units and additional repeat units such as hole transport and / or electron transport repeat units as disclosed, for example, in WO 00/55927. It may be a copolymer containing. Each repeating unit is provided in the main chain or side chain of the polymer.

  Polymers for use as charge transport materials and / or luminescent materials in the devices of the invention are preferably described in, for example, Adv. Mater. 2000, 12 (23) pp. 1737-1750 and references therein, containing repeat units selected from arylene repeat units.

Exemplary first repeat units include J.I. Appl. Phys. 1996, 79, 934; 1,4-phenylene repeating unit; fluorene repeating unit disclosed in European Patent No. 0842208; for example, Macromolecules 2000, 33 (6), indenofluorene disclosed on pages 2016-2020 Repeat units; and spirofluorene repeat units disclosed, for example, in EP 0707020. Each of these repeating units is optionally substituted. Examples of the substituents, C ₁ ~ ₂₀ alkyl or solubilizing groups such as alkoxy; include substituents to increase and the glass transition temperature of the polymer (Tg); fluorine, nitro or electron-withdrawing group such as cyano.

  Particularly preferred polymers comprise optionally substituted 2,7-linked fluorene, most preferably repeating units of formula IV.

In the formula, R ¹ and R ² are independently H or a substituent, and R ¹ and R ² can be linked to form a ring. R ¹ and R ² are preferably hydrogen, alkyl substituted by optionally example C ₁ ~ ₂₀ alkyl (one or more C atoms which are not adjacent in the O, S, substituted N, C = Optionally substituted aryl and heteroaryl, such as phenyl, or straight or branched aryl or heteroaryl groups, such as phenyl groups (of these groups) Each may be independently substituted), for example selected from the group consisting of groups of formula (Ar ³ ) _v below; and optionally substituted arylalkyl or heteroarylalkyl. More preferably, at least one of R ¹ and R ² include C ₄ ~ ₂₀ alkyl or aryl, in particular phenyl group substituted by optionally.

Ar ³ is independently selected from aryl or heteroaryl each occurrence, and r is at least 1, optionally 1, 2 or 3.

When R ¹ or R ² contains one or more aryl groups or heteroaryl groups, those aryl groups or heteroaryl groups are
Alkyl (one or more non-adjacent C atoms of the alkyl group may be replaced by O, S, substituted N, C═O and —COO—, where one or more H atoms of the alkyl group are , F may be substituted), or aryl or heteroaryl optionally substituted with one or more groups R ⁴
Or aryl or heteroaryl optionally substituted with one or more groups R ⁴ ,
NR ⁵ ₂ , OR ⁵ , SR ⁵ ,
May be substituted with one or more substituents selected from the group R ³ consisting of fluorine, nitro and cyano, wherein each R ⁴ is independently alkyl, one or more of the alkyl groups Non-adjacent C atoms of may be replaced with O, S, substituted N, C═O and —COO—, and one or more H atoms of the alkyl group may be replaced with F; Each R ⁵ is independently selected from the group consisting of alkyl, and aryl or heteroaryl optionally substituted with one or more alkyl groups).

When R ¹ or R ² is aryl or heteroaryl, preferred optional substituents include alkyl groups (one or more non-adjacent C atoms are O, S, substituted N, C = O and -COO- may be substituted).

Optional substituents on fluorene units other than substituents R ¹ and R ² are preferably alkyl (one or more non-adjacent C atoms are O, S, substituted N, C═O and —COO Optionally substituted aryl), optionally substituted heteroaryl, selected from the group consisting of optionally substituted heteroaryl, alkoxy, alkylthio, fluorine, cyano and arylalkyl. Preferably, the polymer comprises the aforementioned arylene repeat units and arylamine repeat units, especially repeat unit V.

Wherein Ar ¹ and Ar ² are optionally substituted aryl or heteroaryl groups, n is 1 or more, preferably 1 or 2, and R is H or a substituent, It is preferably a substituent, and x and y are each independently 1, 2 or 3. R may be — (Ar ³ ) _v , where Ar ³ is independently selected from aryl or heteroaryl for each occurrence, and v is at least 1, optionally 1, 2 or 3. When v is greater than 1, — (Ar ³ ) _v can form a straight or branched chain of the Ar ³ group. R is preferably alkyl or aryl or heteroaryl, most preferably aryl or heteroaryl. Including the case where R contains one or more aryl or heteroaryl groups, either the aryl or heteroaryl group of the unit of formula 1 may be substituted. Preferred substituents are alkyl (one or more non-adjacent C atoms may be replaced by O, S, substituted N, C═O and —COO—), optionally substituted aryl Optionally selected from heteroaryl, alkoxy, alkylthio, fluorine, cyano and arylalkyl. Preferred substituents include alkyl groups and alkoxy groups. Either the aryl group or heteroaryl group of the repeating unit of Formula 1 may be linked by a direct bond or a divalent linking atom or linking group. Preferred divalent linking atoms and linking groups include O, S, substituted N, and substituted C.

Each occurrence of Ar ¹ , Ar ² and Ar ³ is preferably phenyl, and each phenyl may independently be substituted with one or more substituents as described above. Exemplary substituents are alkyl, such as C ₁ ~ ₂₀ alkyl.

  The repeating unit of formula (V) can have the following formula where x and y are both 1.

  Particularly preferred units that satisfy Formula 1 include units of Formulas 1-3.

Wherein Ar ¹ and Ar ² are as defined above and Ar ³ is an optionally substituted aryl or heteroaryl. When present, preferred substituents for Ar ³ include alkyl groups and alkoxy groups.

  The polymer comprising repeating units of the formula (V) can be used as a light emitting material in the layer 3 of the OLED or as a hole transport material used in the layer 3 or hole transport layer of the OLED.

  The polymer can comprise one, two or more different repeating units of formula (V). For example, the polymer can include one repeating unit of formula (V) to provide hole transport and another repeating unit of formula (V) to provide emission.

  The arylamine repeat unit is preferably present in an amount of up to 30 mol%, preferably up to 20 mol%. These percentages apply to the total number of arylamine units present in the polymer when more than one type of repeat unit of formula V is used.

  The polymer can include heteroarylene repeat units for charge transport or emission.

  The combination of a triplet accepting unit and a charge transport material or luminescent material can result in an intramolecular triplet accepting pathway that is not available in the corresponding mixed system, so the triplet acceptor material is mixed with the charge transport material or luminescent material. Compared to cases, more efficient triplet acceptance can be provided. When charge transporting polymers and / or light emitting polymers are used, the triplet accepting units can be attached to any repeating unit of the polymer. For example, in the case of a light-emitting polymer, the triplet accepting unit is in the polymer's luminescent repeat unit and / or any other repeat unit of the polymer that can be present, such as an electron transport repeat unit and / or a hole transport repeat unit. Can be combined.

  Further, the coupling can be beneficial for processing reasons. For example, if the compound of formula (I) is poorly soluble, it can be coupled to a soluble charge transport material or luminescent material, in particular a soluble charge transport polymer or luminescent polymer, and triplet accepting by the charge transport material or luminescent material. Units are incorporated into the solution and the device can be manufactured using solution processing techniques. Furthermore, if the triplet accepting unit is a relatively volatile material, the risk of evaporation of the triplet accepting material during device fabrication is eliminated. This means that the charge transport and light-emitting layers formed by solution deposition are generally heated as part of the device fabrication process (eg, to evaporate the solvent), thereby causing a volatile triplet. This is particularly problematic in the case of OLEDs formed using solution processing methods because the probability of evaporating the accepting unit increases. Finally, combining triplet accepting units with charge transport materials or luminescent materials can prevent phase separation effects in solution processed devices that can be detrimental to device performance.

When the luminescent material is a conjugated polymer comprising a luminescent repeat unit and further repeat units, for example a luminescent amine repeat unit of formula (V) and a fluorene repeat unit of formula (IV), conjugation of a triplet accepting unit to the polymer backbone (Eg, due to conjugation with a fluorene repeat unit) reduces the T ₁ energy level of the triplet accepting unit, and thus tends to cause energy to move triplet excitons from the emitter unit to the triplet accepting unit. This reduction in the T ₁ energy level of the triplet acceptor unit allows the triplet acceptor unit to be used in combination with a luminescent material that has a T ₁ level that is too low to be used with such unconjugated triplet acceptor units. It becomes possible.

  A preferred method of preparing conjugated charge transport polymers and emissive polymers involves “metal insertion” in which the metal atom of the metal complex catalyst is inserted between the aryl or heteroaryl group of the monomer and the leaving group. Exemplary metal insertion methods include, for example, Suzuki polymerisation as described in WO 00/53656, and T.W. Yamamoto, “Electrically Conducting And Thermally Stable □ -Conjugated Poly (arylenes) Prepared by Organic Processes, 3rd page, 115th” In the case of Yamamoto polymerization, a nickel complex catalyst is used, and in the case of Suzuki polymerization, a palladium complex catalyst is used.

  For example, in the synthesis of a linear polymer by Yamamoto polymerization, a monomer having two reactive halogen groups is used. Similarly, according to the method of Suzuki polymerisation, at least one reactive group is a boron derivative group such as a boronic acid or boronic ester and the other reactive group is a halogen. Preferred halogens are chlorine, bromine and iodine, most preferably bromine.

  Thus, it will be appreciated that the repeat units shown throughout this application can be derived from monomers bearing appropriate leaving groups. Similarly, end groups or side groups can be attached to the polymer by reaction of a suitable leaving group.

  Suzuki polymerisation can be used to prepare regioregular block copolymers and random copolymers. In particular, homopolymers or random copolymers can be prepared when one reactive group is a halogen and the other reactive group is a boron derivative group. Alternatively, block copolymers or stereoregular copolymers, especially AB copolymers, can be prepared when both reactive groups of the first monomer are boron and both reactive groups of the second monomer are halogen. it can.

  As an alternative to halides, other leaving groups that can participate in metal insertion include groups including tosylate, mesylate and triflate.

  The light-emitting layer 3 can consist only of the light-emitting polymer and the triplet accepting unit, or can comprise these materials in combination with one or more further materials. In particular, the light-emitting polymer can be blended with a hole and / or electron transport material, or can be covalently bonded to the hole and / or electron transport material, for example as disclosed in WO 99/48160.

  The light emitting copolymer can comprise a light emitting region and at least one of a hole transport region and an electron transport region, as disclosed, for example, in WO 00/55927 and US Pat. No. 6,353083. If only one of the hole transport region and the electron transport region is provided, the electroluminescent region can also provide the other of the hole transport functionality and the electron transport functionality, for example, the aforementioned amine unit can be Both hole transport and light emission functionality can be provided. A luminescent copolymer comprising a luminescent repeat unit and one or both of a hole transport repeat unit and an electron transport repeat unit can provide said unit in the polymer backbone, as disclosed in US Pat. No. 6,353083, or The unit can be provided from the polymer backbone to the pendant polymer side group.

The light emitting polymer can emit any color, provided that its S ₁ and T ₁ energy levels relative to the triplet accepting unit are as described above, but the light emitting polymer is preferably a blue light emitting polymer. In particular, it is a material having a photoluminescent emission with a peak wavelength in the range of 400 to 500 nm, preferably 430 to 500 nm.

  The light emitting layer 3 may be patterned or may not be patterned. A device comprising an unpatterned layer can be used, for example, as an illumination light source. White light emitting devices are particularly suitable for this purpose. The device comprising the patterned layer can be, for example, an active matrix display or a passive matrix display. For active matrix displays, the patterned emissive layer is generally used in combination with a patterned anode layer and an unpatterned cathode. In the case of a passive matrix display, the anode layer is formed from parallel stripes of anode material and parallel stripes of electroluminescent and cathode materials arranged perpendicular to the anode material, the electroluminescent and cathode materials The stripes are generally separated by stripes of insulating material (“cathode separator”) formed by photolithography.

B. Emission When a unit of formula (I) is used as the luminescent material, this unit can be used in combination with a host material such as a polymeric host material (receive singlet excitons from this host material), in this case, S ₁ level of the units of formula (I) is lower than the S ₁ level of the host, or at least less S ₁ level of the host.

  The unit of formula (I) may be a compound that is physically mixed with the host material but not chemically bonded. Alternatively, the unit of formula (I) can be chemically bonded to the host material. In the case of a polymeric host material, the unit of formula (I) can be provided as a repeating unit of the polymer backbone or can be attached to the polymer as a side chain group or a terminal group. Suitable luminescent compounds of formula (I), repeat units, side chain groups and end groups are as described above for triplet acceptor materials.

Suitable host materials in this case include fluorene homopolymers or copolymers containing fluorene units, and one or more comonomer repeat units having a higher S ₁ level than units of formula (I) ) Is included.

  Exemplary materials, methods and device structures for OLEDs are described in more detail below. The structures of these materials, methods and devices are the same as those of formula (I), regardless of whether the unit comprising the unit of formula (I) functions as an emitter unit or as a triplet accepting unit that does not substantially emit light. It will be understood that the present invention can be applied to an OLED including the following units.

Hole injection layer A conductive hole injection layer, which can be formed from a conductive organic material or an inorganic material, is provided between the anode 2 and the light emitting layer 3, from the anode to one or more layers of the semiconducting polymer. It can be used to inject holes.

  Examples of doped organic hole injection materials include optionally substituted doped poly (ethylenedioxythiophene) (PEDT), particularly as disclosed in EP 0901176 and EP 0947123. PEDT doped with charge balancing polyacids such as polystyrene sulfonate (PSS), polyacrylic acid or fluorinated sulfonic acids such as Nafion®; polyaniline disclosed in US Pat. No. 5,723,873 and US Pat. No. 5,798,170; As well as optionally substituted polythiophene or poly (thienothiophene). Examples of conductive inorganic materials include transition metal oxides such as VOx MoOx and RuOx, such as those disclosed in Journal of Physics D: Applied Physics (1996), 29 (11), pages 2750-2754. included.

Charge Transport Layer A hole transport layer can be provided between the anode and the light emitting layer. Similarly, an electron transport layer can be provided between the cathode and the light emitting layer.

  Similarly, an electron blocking layer can be provided between the anode and the light emitting layer, and a hole blocking layer can be provided between the cathode and the light emitting layer. The transport layer and blocking layer can be used in combination. Depending on its HOMO and LUMO levels, a single layer can transport one of holes and electrons and block the other of holes and electrons.

  When present, the hole transport layer located between the anode 2 and the light emitting layer 3 preferably has a HOMO level of 5.5 eV or less, more preferably about 4.8 to 5.5 eV. The HOMO level can be measured, for example, by cyclic voltammetry.

  When present, the electron transport layer located between the light emitting layer 3 and the cathode 4 preferably has a LUMO level of about 3 to 3.5 eV. For example, a layer of silicon monoxide or silicon dioxide, or other thin dielectric layer having a thickness in the range of 0.2-2 nm is provided between the light-emitting layer 3 and the layer 4.

  Polymers for use as charge transport materials can include arylene units such as the fluorene unit of formula (IV) and other units described above.

  The hole transport polymer may comprise a repeat unit of formula (V), such as an arylamine repeat unit, in particular the repeat unit of formulas 1-3 described above. The polymer may be a homopolymer or a copolymer comprising arylene repeat units in an amount up to 95 mol%, preferably up to 70 mol%. These percentages apply to the total number of arylamine units present in the polymer when two or more repeating units of formula (V) are used.

  The charge transport unit can be provided on the polymer main chain or the polymer side chain.

  If present, the charge transport layer can comprise a charge transport material and a triplet absorbing material in a modification similar to that described above, in which case the light emitting layer 3 may comprise a triplet accepting unit. Or may not be included.

Cathode The cathode 4 is selected from materials having a work function capable of injecting electrons into the electroluminescent layer. Other factors, such as the possibility of deleterious interactions between the cathode and the electroluminescent material, also affect cathode selection. The cathode can be made of a single material such as an aluminum layer.

  Alternatively, the cathode can comprise a plurality of metals, for example, a bilayer of a low work function material and a high work function material, such as calcium and aluminum disclosed in WO 98/10621; WO 98/57381, Appl. Phys. Lett. Elemental barium disclosed in 2002, 81 (4), 634 and WO02 / 84759; or metal compounds, particularly alkali metal or alkaline earth metal oxides, as disclosed in WO00 / 48258, to aid electron injection Or a thin layer of fluoride, such as lithium fluoride; Appl. Phys. Lett. 2001, 79 (5), 2001, barium fluoride; as well as barium oxide. In order to efficiently inject electrons into the device, the cathode preferably has a work function of less than 3.5 eV, more preferably less than 3.2 eV, and most preferably less than 3 eV. Metal work functions are described, for example, in Michaelson, J. et al. Appl. Phys. 48 (11), 4729, 1977.

  The cathode can be opaque or transparent. Transparent cathodes are particularly advantageous in active matrix devices, as light passing through the transparent anode in the active matrix device is at least partially blocked by a drive circuit located under the luminescent pixel. The transparent cathode includes a layer of electron injection material that is sufficiently thin and transparent. In general, the lateral conductivity of this layer is low as a result of its thinness. In this case, the layer of electron injecting material is used in combination with a thicker layer of transparent conductive material such as indium tin oxide.

  Transparent cathode devices do not require a transparent anode (unless of course a completely transparent device is desired), and therefore transparent anodes used in bottom light emitting devices are layers of reflective material such as an aluminum layer. It will be understood that can be replaced or supplemented with. An example of a transparent cathode device is disclosed, for example, in GB 2348316.

Sealed OLEDs tend to be sensitive to moisture and oxygen. Thus, the substrate preferably has good barrier properties to prevent moisture and oxygen from entering the device. The substrate is typically glass, but alternative substrates can be used, particularly where device flexibility is desired. For example, the substrate may be a plastic such as in US Pat. No. 6,268,695 which discloses a substrate with alternating plastic and barrier layers, or a thin glass and plastic laminate disclosed in EP 0949850. Can be included.

  The device is preferably sealed with an encapsulant (not shown) to prevent moisture and oxygen ingress. Suitable encapsulants include glass sheets, films with suitable barrier properties such as silicon dioxide, silicon monoxide, silicon nitride, or alternately stacked with polymers and dielectrics as disclosed, for example, in WO01 / 81649 Or hermetic containers disclosed, for example, in WO 01/19142. For transparent cathode devices, a transparent sealing layer such as silicon monoxide or silicon dioxide can be deposited to a micron level thickness, but in a preferred embodiment, the thickness of such layer is 20-300 nm. It is a range. Any atmospheric moisture and / or oxygen getter material that can penetrate the substrate or encapsulant can be deposited between the substrate and encapsulant.

Solution Treatment The light emitting layer 3 can be deposited by any method including vacuum evaporation and deposition from a solution in a solvent. When the emissive layer includes polyarylene such as polyfluorene, suitable solvents for solution deposition include mono- or poly-alkylbenzenes such as toluene and xylene. Particularly preferred solution deposition techniques include printing and coating techniques, preferably spin coating and ink jet printing.

  Spin coating is particularly suitable for devices that do not require patterning of electroluminescent materials, such as lighting applications or simple monochrome segment displays.

  Inkjet printing is particularly suitable for displays with a large amount of information, in particular full color displays. The device prints by providing a patterned layer on the first electrode and defining wells for single color (for monochrome devices) or multiple colors (for multicolor, especially for full color devices) printing Can be inkjet. The layer to be patterned is generally a photoresist layer that is patterned to define wells, for example as described in EP 0880303.

  As an alternative to wells, ink can be printed in channels defined in the patterned layer. In particular, a photoresist can be patterned to form a channel, which, unlike a well, extends over a plurality of pixels and may be closed or open at the end of the channel.

  Other solution deposition techniques include dip coating, roll printing and screen printing.

  When multiple layers of an OLED are formed by solution processing, those skilled in the art will know, for example, by cross-linking one layer and then depositing subsequent layers or the material that forms the first layer of the adjacent layer. One will recognize techniques for preventing admixing of adjacent layers by selecting the material of the adjacent layers so that they do not dissolve in the solvent used to deposit the second layer.

Material Examples Compounds of formula (I) were prepared according to the following synthetic method.

  A material 12 that quenches the triplet, a reactive compound 13 to form a terminal or side chain group of the polymer that quenches the triplet, and monomers 14, 16, and 18 that form repeating units that quench the triplet, Prepared according to the following method.

Compound 2
To an ice-cooled solution of p-xylylene bis (triphenylphosphonium bromide) (81.3 g, 103 mmol) and p-bromobenzaldehyde (38.3 g, 207 mmol) in anhydrous tetrahydrofuran (1000 ml) was added sodium tert-butoxide (22.0 g, 229 mmol) was added and the reaction mixture was allowed to warm to room temperature with stirring overnight. After work-up with aqueous solution and treatment with iodine in refluxing toluene, the title compound was isolated as a yellow solid (20.3 g, 46 mmol).

Compound 3
To a solution of compound 2 (4.40 g, 10 mmol) in anhydrous tetrahydrofuran (200 ml) cooled to −78 ° C. was added n-butyllithium (2.5 M in hexane, 12 ml, 30 mmol) followed by isopropoxyboronic acid. Pinacol ester (5.60 g, 30 mmol) was added. The reaction mixture was warmed to room temperature and quenched with acid. Column chromatography (silica, toluene) gave the title compound as a yellow solid (2.95 g, 5.5 mmol).

Compound 5
Compound 3 (1.21 g, 2.3 mmol), Compound 4 (1.80 g, 5.5 mmol) and bis (triphenylphosphine) palladium (II) dichloride (0.088 g, 0.0 mmol) in toluene (75 ml). 13 mmol) and tetraethylammonium hydroxide (20 wt% in water, 15 ml, 20 mmol) were stirred under reflux overnight. After work-up with an aqueous solution, column chromatography (silica, hexane / toluene) and recrystallization gave the title compound as a yellow solid (0.44 g, 0.6 mmol).

Compound 7
Compound 6 (10.0 g, 27 mmol) and 1-bromo-4-iodobenzene (11.4 g, 40 mmol), silver carbonate (14.8 g, 54 mmol) and tetrakis (triphenylphosphine) palladium in anhydrous tetrahydrofuran (200 ml) A solution of (0) (3.11 g, 2.7 mmol) was refluxed overnight. Column chromatography (silica, hexane) gave the title compound as a colorless oil (4.07 g, 10 mmol).

Compound 8
Following the procedure described for compound 5, compound 3 (2.47 g, 4.6 mmol) and compound 7 (4.05 g, 10 mmol) were used to give the title compound as a yellow solid (2.0 g, 2.2 mmol). ).

Compound 10
To a solution of compound 9 (20.0 g, 29 mmol) in anhydrous tetrahydrofuran (300 ml) cooled to −78 ° C. was added n-butyllithium (2.5 M in hexane, 11.5 ml, 29 mmol) followed by water ( 10 ml, 555 mmol) was added. The reaction mixture was warmed to room temperature. Column chromatography (silica, hexane / toluene) gave the title compound as a colorless oil (6.0 g, 9.7 mmol).

Compound 11
Following the procedure described for compound 5, compound 3 (1.84 g, 3.4 mmol) and compound 10 (4.67 g, 7.1 mmol) were used to give the title compound as a yellow solid (0.84 g, 0 .6 mmol).

Compound 12
Dry tetrahydrofuran (500 ml) was added to a mixture of fluorene (10.00 g, 60.16 mmol) and potassium tert-butoxide (7.43 g, 66.18 mmol) under nitrogen and stirred at room temperature for 5 minutes. Benzophenone (10.96 g, 60.16 mmol) was then added as a solid and the reaction mixture was stirred at room temperature under nitrogen for an additional 20 hours. Then, an aqueous ammonium chloride solution (saturated, 200 ml) was added and stirred until the color of the aqueous solution disappeared. Diethyl ether (100 ml) was added and the aqueous layer was separated and extracted with diethyl ether (2 × 100 ml). The combined organic layer was washed with water (3 × 200 ml), dried over anhydrous magnesium sulfate and evaporated. The crude product (16.0 g) was recrystallized twice from dichloromethane: hexane (100: 200 ml), then recrystallized from dichloromethane: acetonitrile (100: 200 ml) and then dried under vacuum to give 9 White crystals of-(diphenylmethylene) -9H-fluorene (7.34 g) were obtained.

Compound 13
Following the procedure described in Compound 12, using fluorene (31.83 g, 191.5 mmol) and 3-bromobenzophenone (50.00 g, 191.5 mmol) and then recrystallizing from dichloromethane: hexane, the title compound Was obtained as an off-white crystalline solid (62.11 g, 162 mmol).

Compound 14
A solution of compound 13 (30.00 g, 73.29 mmol) in dry tetrahydrofuran (200 ml) was cooled to less than −70 ° C. under nitrogen in an acetone / dry ice bath and then n-butyllithium (2 in hexane). 0.5M, 28.0 ml, 70.1 mmol) was added dropwise. The reaction mixture was stirred below 90 ° C. for 90 minutes, then a solution of ethyl 4,4′-dibromobiphenyl-2-carboxylate (11.79 g, 31.9 mmol) in dry tetrahydrofuran (40 ml) was added dropwise. The reaction mixture was allowed to warm to room temperature with stirring for an additional 40 hours.

  Then an aqueous ammonium chloride solution (saturated, 50 ml) was added and stirred for 20 minutes. Then diethyl ether (200 ml) was added and the aqueous layer was separated and extracted with diethyl ether (2 × 50 ml). The combined organic layer was washed with water (3 × 100 ml), dried over anhydrous magnesium sulfate and then evaporated. The crude product intermediate was dissolved in dry dichloromethane (200 ml) under nitrogen and cooled in a sodium chloride / ice bath. Boron trifluoride etherate (38 ml) was added dropwise and the dark solution was stirred overnight and allowed to warm to room temperature. The reaction mixture was then poured onto ice / water (500 ml) and aqueous potassium phosphate (20 g in 200 ml) was added and stirred for 1 hour. The aqueous layer was separated and extracted with dichloromethane (2 × 50 ml), the combined organic layers were washed with water (2 × 100 ml), dried over anhydrous magnesium sulfate and then evaporated to give an orange oil . This oil was triturated twice with hexane and then recrystallized from toluene: acetonitrile to give the title compound (20.5 g, 20.9 mmol).

Compound 15
n-Butyllithium (95 ml, 2.5 M in hexane, 238 mmol) was added to a solution of 2,7-di-tert-butylfluorene (66.3 g, 238 mmol) in dry diethyl ether (1.4 L) in an ice bath. Medium, added dropwise under nitrogen, then stirred for 20 minutes. Chlorotrimethylsilane (40 ml, excess) was added and stirred for 6 hours while gradually warming to room temperature. Water (500 ml) was added and the organic layer was separated, washed with water (3 × 100 ml), dried over anhydrous magnesium sulfate and evaporated to give an orange solid. Recrystallisation from heated hexanes afforded the title compound (60.7 g, 73%).

Compound 16
n-Butyllithium (7.4 ml, 2.5 M in hexane, 18 mmol) was added to 2,7-di-tert-butyl-9-trimethylsilylfluorene (7.11 g, 20.2 mmol) in dry diethyl ether (100 ml). Was slowly added under nitrogen at 0 ° C. and stirred for 15 minutes. Dibromobenzaldehyde (4.87 g, 18.4 mmol) was added and the reaction was stirred at room temperature for 2 hours. Water (50 ml) was added and the organic layer was separated, washed with water (3 × 30 ml), dried over anhydrous magnesium sulfate and evaporated to give an orange oil. Recrystallisation from hexane, acetonitrile and propan-2-ol gave the title compound.

Compound 17
Thionyl chloride (100 ml) was added to 3,5-dibromobenzoic acid (50.0 g, 178 mmol) and heated to reflux for 6 hours. Excess thionyl chloride was then removed by distillation and the remaining brown solid was dissolved in dry tetrahydrofuran (1 L) and cooled to below −70 ° C. under nitrogen in an acetone / dry ice bath. Phenylmagnesium bromide solution (179 ml, 1M in tetrahydrofuran, 179 mmol) was added dropwise to the cooled reaction mixture, which was then allowed to warm to room temperature with stirring for 4 hours. Water (200 ml) was carefully added followed by diethyl ether (200 ml). The aqueous layer was separated and extracted with diether ether (2 × 50 ml), then the combined organic layers were washed with water (3 × 100 ml), dried over magnesium sulfate and evaporated. Trituration with methanol gave a white solid that was recrystallized from hexane to give the title compound (23.66 g).

Compound 18
According to the procedure described for compound 12, 2,7-di-tert-butylfluorene (19.37 g, 69.6 mmol) and 3,5-dibromobenzophenone (23.66 g, 69.6 mmol) were used followed by hexane. And recrystallized from silica gel (eluting with 5% dichloromethane: hexane) and further recrystallized from dichloromethane: methanol to give the title compound as a yellow solid (0.90 g).

Compound 19

  Compound 19 was prepared by the reaction of intermediate 17 shown above according to the method shown above for compound 18 as follows.

  Potassium tert-butoxide (39.16 g, 342 mmol) was added to a solution of fluorene (58.0 g, 342 mmol) in dry tetrahydrofuran (400 ml) under nitrogen and stirred at room temperature until completely dissolved. The reaction mixture was then cooled to −75 ° C. and a solution of 3,5-dibromobenzophenone (116.3 g, 342 mmol) in dry tetrahydrofuran (350 ml) was added dropwise while maintaining the temperature below −70 ° C. Then it was warmed to room temperature with stirring overnight. The reaction was then cooled and aqueous ammonium chloride (saturated, 250 ml) was added and stirred at 0 ° C. for 20 minutes, then the tetrahydrofuran was removed under vacuum. Water (1 L) was added and extracted with dichloromethane (3 × 250 ml) and the combined organic fractions were washed with water (3 × 300 ml), dried over magnesium sulfate and evaporated to give a brown oil. After purification by column chromatography (increasing hexane + dichloromethane), trituration with hexane and recrystallization from dichloromethane: methanol gave the desired product as a pale yellow solid (38.2 g).

Device Example 1-Triplet Acceptance A device having the following structure was formed.
ITO / HIL / HTL / EL / MF / Al
ITO represents an indium tin oxide anode, and HIL is from Plextronics Inc. A hole injection layer formed from a hole injection material available from HTL, wherein the HTL is a polymer hole transport layer comprising a fluorene repeat unit of formula (IV) and an amine repeat unit of formula (V); EL is a light emitting layer comprising fluorene repeat units of formula (IV) and amine repeat units of formula (V) blended with 0.25 mol% DPVBi, MF is a metal fluoride, and MF / Al The two layers form the cathode of the device.

Device Examples 2-4-Triplet Acceptance Three additional devices were prepared as above except that DPVBi was provided at concentrations of 0.5, 1 and 3 mol% (devices 2, 3 and 4 respectively).

As shown in FIG. 5, device 3 has an electroluminescence spectrum (B) that is substantially identical to the electroluminescence spectrum (A) of the comparative device in the absence of the triplet acceptor compound, This indicates that the S ₁ energy level of the triplet acceptor compound is higher than the S ₁ energy level of the light emitting unit of the polymer.

As shown in FIG. 6, the T ₉₀ lifetime (ie, the time it takes for the device brightness at a constant current to drop to 90% of its original brightness) is, in all cases, that of the exemplary devices 1-4. Is longer than the comparative device (C), and the lifetime decay curve is significantly flat compared to the curve of the comparative device (C) where the brightness first drops sharply before flattening.

  FIG. 7 shows that the characteristics of the current density with respect to the voltage of the device 3 (dotted line) and the comparative device (solid line) are substantially the same.

  FIG. 8 shows a decrease in external quantum efficiency when device 3 (dotted line, E) is compared with a comparative device (solid line, F). This is expected in the case of the present invention where the triplet is quenched so that the triplet triplet-triplet annihilation present on the light-emitting polymer does not occur, but the efficiency is As described above, it can be repaired by causing triplet-triplet annihilation.

Device Example 5
A device was formed as in Device Example 1. In this device, the HTL comprises 50:50 mol of copolymer F8-TFB (poly- (9,9-dioctylfluorene-N- (4- (2-butyl) phenyl) -diphenylamine)) and EL is triplet Is blended with DPVBi (4,4′-bis (2,2′diphenylvinyl) -1,1′-biphenyl), a quenching additive (1% mol ratio) of 95: 5 mol copolymer F8-PFB (poly -(9,9'-dioctylfluorene-co-bis-N, N '-(4-butylphenyl) -bis-N, N'-phenyl-1,4-phenylenediamine)).

  DPVBi has the triplet energy of the red-green part of the spectrum (Chen, P. et al., White organic light-emitting devices with a bipolar transport. And the physic. 0230505-3 (2007); Schwartz, G., Fehse, K., Pfeiffer, M., Walzer, K. & Leo, K. Highly efficient whitening organics competing compres- e. fluorescent and phosphorescent regions. Applied Physics Letters 89, 083509 (2006); and Romanovskii, YV and et al., Phosphorescence of pi. con. ).

  DPVBi also has a high singlet energy (3.2 eV) compared to the luminescent polymer, so this molecule accepts the triplet of the polymer without affecting the singlet emission state. This is confirmed by the observation that incorporating this small molecule into the polymer has no effect on the device's photoluminescence intensity or spectrum.

  Singlet and triplet exciton dynamics were studied using time-resolved electroluminescence, and absorption of quasi-cw and time-resolved excited states. Excited state absorption techniques have been described elsewhere (King, S., Rothe, C. & Monkman, A. Triple build in and dehydrated polyspirobifluorine chains in dilute solution. 10808 (2004), and Dhoot, AS, Ginger, DS, Beljonne, D., Shuai, Z. & Greenham, N. C. Triple formation and deci- cation of dehydrated polymer 3 195-201 (2002)), polyfluore Using these techniques, the triplet state is well characterized by the strong excited-state absorption properties having a peak at 780 nm due to the triplet state (King, S., Rothe, C. et al. & Monkman, A. Triple build in and decay of isolated polyspirobifluorine chains in dilute solution.J. Chem. Phys. 121, 10803-10, Ro. & Monkman, AP Triplet exciton state and related phenomena in the beta-phase of poly (9,9-dioc) yl) fluorene.Physical Review B70 (2004 years)). Although the investigation of polyfluorene triplet populations was conducted at 780 nm, those skilled in the art will understand how to adapt this investigation to other emissive materials and based on the excited state absorption properties of those materials.

  FIG. 9 shows the external quantum efficiency (EQE) of device example 5 (diamonds) and the external quantum efficiency (squares) of a comparative device without the triplet quenching additive. Devices containing additives that quench the triplet show a significant decrease in peak EQE of about 20% at high voltage. The loss of efficiency occurs without changing the electroluminescence spectrum of the device. Thus, as can be expected from singlet energy, the additive does not quench singlet excitons and does not participate in the emission of the device. Without being bound by any theory, it is believed that the loss of efficiency is caused by the removal of the TTA component by quenching the triplet from the light emitting polymer.

  The density of triplet excitons on the polymer backbone is measured using quasi-cw excited state absorption as outlined above.

FIG. 10 shows the triplet density both on the polymer backbone with a triplet quencher (diamonds, circles) and without the polymer backbone (squares), and for devices with additives, the triplet on the fluorene backbone is shown. The term density is about 1 / 10th lower, so the additive is very efficient at quenching triplets from the polymer at all device drive voltages. Literature values for the extinction coefficient of absorption of triplet excited states in conjugated polymers range from 10 ⁻¹⁶ to 10 ⁻¹⁵ cm ² , which gives a typical drive current of 50 mAcm ⁻² for standard devices. The triplet density of 10 ¹⁶ to 10 ¹⁷ cm ^-3 occurs at, and the decay is dominated by the extinction of the triplet of each other's bimolecule that results in the generation of luminescent singlet excitons.

  FIG. 11 shows time-resolved electroluminescence (white squares, white circles) during turn-off of Device Example 2 compared to time-resolved triplet transient absorption (black squares) and its square (black circles). The dotted line has the same slope. Also shown is the effect on electroluminescence turn-off when a reverse bias pulse of -10 v 200 ns duration is applied to the device 250 ns after the device current is switched off.

  After turning off the current, first, there is a rapid decay of brightness on a time scale similar to the RC time constant of the device, followed by an EL residual signal, which is approximately the same as the original total electroluminescence. It accounts for 30% and decays in a few microseconds. In general, slow transient emission of OLEDs is attributed to either deep traps or charge recombination from the interfacial charge layer, or TTA (Kondakov, DY Characteristic of triplet-triplet in organic lighting-emittering. based on anthracene derivatives.J. Appl. from Pristine Polyfluorene Thin Film Devices at Low Temperature. Physical Review Letters 90, 127402 (2003), and Sinha, S., Monkman, AP, Gunner, R. & Sr. thin films.Appl.Phys.Lett.82, p.4693-4695 (2003)).

  To distinguish the two mechanisms, the same transient electroluminescence trace was measured 100 ns after the device current was turned off, with a 10 v reverse bias pulse applied, which pulse contributes to the luminance decay. The trap charge is removed or at least significantly disturbed. The data shows that due to quenching by the electric field of singlet excitons, the emission is slightly quenched during the reverse bias pulse, but the EL decay after the reverse bias pulse is unchanged compared to the standard decay form It is shown that. Thus, it can be concluded that the recombination of trapped charges is not a significant cause of the residual luminance signal (Popovic, ZD & Aziz, H. Delayed electroluminescence in small-molecular-lighted organic light-emitting orients: Evidence: triplet-triplet anihilation and recombination-center-mediated light-generation mechanism. J. Appl. Phys. 98, 013510-5 (2005))). Furthermore, when the shape of the residual luminescence is compared with the triplet density (shown in FIG. 11), two things are observed. First, the triplet decay time scale is similar to the EL decay, but more importantly, the approximate slope of the residual luminance decay is very similar to the slope of the triplet density squared. Yes. This observation is strong evidence that the EL residual decay is due to a bimolecular triplet-triplet annihilation reaction leading to a luminescent singlet exciton. Because triplets are much more stable than singlets with respect to the electric field due to their inherently high exciton binding energies, the density of triplet excitons is determined by applying a reverse bias pulse of 10v. Is not significantly quenched (Rothe, C., King, SM & Monkman, AP Electric-field-induced single and triple olfighting of films. Phys. Rev. B72, 085220 (2005) and Deussen, M., Scheidler, M. & Bassler, H. Electric-Field- nduced Photoluminescence Quenching in Thin-Film Light-Emitting-Diodes Based on Poly (Phenyl-P-Phenylene Vinylene), pp. .Synth.Met.73,123~129 (1995 years)).

  FIG. 12 shows the electroluminescence decay of both the device with the triplet quenching additive (dotted line) and the device without (solid line), but the effect on lifetime is obvious and T90 is improved about 5 times. And the final device lifetime is improved by more than three times. The lower panel of FIG. 5, which shows the efficiency of the device during the life test, shows that the attenuation of the two devices is remarkably similar since the additional efficiency gain due to the TTA contribution is lost early in the life test. It is clearly stated.

  The cost for extending this lifetime is a 20% reduction in EQE due to complete removal of TTA, and it is much more important to stabilize this initial decay. In a further variation, both high efficiency and long life can be achieved by utilizing a stable TTA as described above.

Device Example 6 Triplet Acceptance A blue emitting polymer was prepared by Suzuki polymerization of the following monomers using the method described in WO 00/53656.

  A monomer containing asymmetrically substituted fluorene was prepared according to the following scheme.

(I) a) n-BuLi, THF, -76 ° C, b) 2,7-dibromofluorenone, from -76 ° C to r. t. (Ii) Et ₃ SiH, TFA, hexane, r. t. , (Iii) Mel, KOH, DMSO / H ₂ 0, r. t.

  The phenoxazine-based monomer was prepared according to the method disclosed in WO2010 / 001982.

Devices having the following structure were formed using these polymers.
ITO / HIL / HTL / LE / cathode HIL is a hole injection layer containing a hole injection material, and HTL comprises a luminescent polymer comprising a fluorene repeat unit of formula (IV) and an amine repeat unit of formula (V). A hole transport layer formed by spin coating, LE is a light emitting layer formed by spin coating polymer example 1, polymer example 2 or comparative polymer 1, and a cathode emits light. A metal fluoride layer in contact with the layer and an aluminum layer formed on the metal fluoride layer.

  With respect to FIG. 13, the presence of repeat units 1 and 2 that quench the triplet in polymer example 1 (dashed line) and polymer example 2 (dotted line) is the emission of the polymer, respectively, compared to comparative polymer 1 (solid line). It can be seen that there is little or no effect on, which indicates that repeat units 1 and 2 that quench the triplet are substantially not luminescent.

  With respect to FIG. 14, the current densities of Comparative Polymer 1, Polymer Example 1 and Polymer Example 2 are similar.

  With respect to FIG. 15, in Polymer Example 1 and Polymer Example 2, a decrease in external quantum efficiency (EQE) is observed compared to Comparative Polymer 1. This is expected in the case of the present invention where the triplet is quenched so that the triplet triplet-triplet annihilation present on the light-emitting polymer does not occur, but the efficiency is As described above, it can be repaired by causing triplet-triplet annihilation.

  With respect to FIG. 16, the half-life (ie, the time taken for the device brightness at a constant current to drop to 50% of its initial brightness) was measured. The half-life (dotted line and dashed line) of the device containing polymer examples 1 and 2 is about twice or more than the half-life (solid line) of the device containing comparative polymer 1.

Emission from the compound of formula (I) FIG. 17 shows the photoluminescent spectrum (solid line) of the host polymer alone and the photoluminescent spectrum (dotted line) in the composition containing DPVBi. This composition can be used in a light emitting device in which the light emitting material is DBVBi.

  Although the invention has been described with reference to specific exemplary embodiments, various modifications, changes and / or combinations of the features disclosed herein can be made from the scope of the invention as set forth in the claims below. It will be understood that it will be apparent to those skilled in the art without departing.

Claims (26)

A fluorescent light-emitting polymer comprising a fluorescent light-emitting repeating unit and a triplet-accepting repeating unit having a triplet energy level lower than the triplet energy level of the light-emitting repeating unit, wherein the triplet-accepting repeating unit has the formula The fluorescent light-emitting polymer having

Wherein each Ar independently represents an optionally substituted aryl or heteroaryl group, n is 1-3, and m is independently 1-5 each time it appears. Yes, q is 0 or 1, each R ³ is independently selected from H or a substituent, each R ⁴ is independently selected from H or a substituent, R ³ and / or R ⁴ Is optionally substituted phenyl,
Here, when R ⁴ is not H, R ⁴ and (Ar) _m bonded to the same carbon atom may be linked by a direct bond or a divalent group, and when R ³ is not H, R 4 ³ (independently every occurrence) and (Ar) _n may be linked by a direct bond or a divalent group, and when n or m is at least 2, adjacent Ar groups are divalent May be linked by a group, provided that when q = 0, R ³ is not H, but is linked to (Ar) _n by a direct bond or a divalent group]. The polymer of claim 1, wherein q = 1. The polymer of claim 2, wherein each R ³ is H. The polymer of claim 2, wherein each R ⁴ is H or — (Ar) _m . The polymer of claim 1, wherein q = 0. R ³ is (Ar) _n, a polymer of claim 5. The polymer according to any one of claims 1 to 6, wherein n is 1 or 2. A divalent linking group links adjacent Ar groups ; R ⁴ and (Ar) _m ; or R ³ and (Ar) _n , wherein the divalent linking group is — (CR ⁵ R _{^{6) p -, - (SiR}} 5 R 6) p -, O, is selected from NR ⁵ and PR ^5, R ⁵ and R ⁶ are each independently selected from H or a substituent, p is 1 The polymer according to claim 1, which is 5. 9. The polymer according to any of claims 1 to 8, wherein at least one Ar group is optionally substituted phenyl. 10. A polymer according to claim 9, wherein all Ar groups are optionally substituted phenyl. The polymer of claim 1, wherein q = 0, n = 1, R ³ is optionally substituted phenyl, and R ³ and (Ar) _n are linked by a direct bond. R ³ and (Ar) _n are linked, form an optionally fluorene substituted polymer according to claim 11. R ⁵ and R ⁶ are each independently selected from H or a substituent, wherein the substituent is
Alkyl (one or more non-adjacent C atoms may be replaced with O, S, substituted N, C═O and —COO—, and one or more H atoms may be replaced with F; Or aryl, heteroaryl, arylalkyl or heteroarylalkyl, each of which may be substituted with halogen, cyano or alkyl (one or more non-adjacent C atoms are O, S, substituted N, C = O and -COO- may be substituted)))
9. The polymer of claim 8, selected from the group consisting of: At least one Ar group is halogen; cyano; alkyl (one or more non-adjacent C atoms may be replaced by O, S, substituted N, C═O and —COO—); and — (Ar ⁴ ) _z (Ar ⁴ is independently selected from optionally substituted aryl or heteroaryl for each occurrence, z is at least 1 , and when z is greater than 1, a plurality of Ar ⁴ 14. A polymer according to any one of the preceding claims, wherein the groups are linked with at least one substituent selected from (which can form a linear or branched chain of Ar ⁴ groups) . 11. A polymer according to claim 9 or 10, wherein at least one meta position of at least one terminal Ar group is substituted with a substituent according to claim 14. The polymer of claim 1, wherein the polymer comprises amine repeat units. The polymer according to any one of claims 1 to 16, wherein the triplet accepting repeating unit is present in an amount of at least 0.05 mol% based on the fluorescence emitting repeating unit. The polymer of claim 1, wherein the triplet accepting repeat unit has one of the structures shown below.

A fluorescent light-emitting polymer comprising a fluorescent light-emitting repeating unit and a triplet-accepting repeating unit having a triplet energy level lower than the triplet energy level of the light-emitting repeating unit, wherein the triplet-accepting repeating unit has the formula The fluorescent light-emitting polymer having

Wherein each Ar independently represents an optionally substituted aryl or heteroaryl group, n is 1-3, and m is independently 1-5 each time it appears. Yes, q is 0 or 1, each R ³ is independently selected from H or a substituent, each R ⁴ is independently selected from H or a substituent, and R ⁴ is not H, R ⁴ and (Ar) _m bonded to the same carbon atom may be linked by a direct bond or a divalent group, and when R ³ is not H, R ³ (independently every occurrence) and (Ar) _n may be linked by a direct bond or a divalent group, and when n or m is at least 2, adjacent Ar groups may be linked by a divalent group, provided that When q = 0, R ³ is not H, but a direct bond or a divalent group. (Ar) _n and at least one Ar group is halogen; cyano; alkyl (one or more non-adjacent C atoms are O, S, substituted N, C═O and may be replaced -COO- in); and _{^{- (Ar 4) z (Ar}} 4 is independently at each occurrence, is selected from optionally substituted aryl or heteroaryl, z is the least Yes , when z is greater than 1, the plurality of Ar ⁴ groups are linked with at least one substituent selected from which can form a straight or branched chain of Ar ⁴ groups) ]. A solution comprising a solvent and a polymer according to any of claims 1-19. A light emitting layer comprising an anode, a cathode, a light emitting layer between the anode and the cathode, and optionally one or more layers selected from a charge transport layer and a charge blocking layer between the anode and the cathode 21. An organic light emitting device, wherein at least one of the one or more optional layers comprises a polymer according to any one of claims 1-19. 22. A method of forming an organic light emitting device according to claim 21, comprising depositing the solution of claim 20 and evaporating the solvent. Use of an optionally substituted triplet accepting unit to accept triplet excitons generated by a fluorescent organic light emitting polymer comprising a fluorescent organic light emitting repeat unit and a triplet accepting unit having the formula:

Wherein each Ar independently represents an optionally substituted aryl or heteroaryl group, n is 1-3, and m is independently 1-5 each time it appears. Yes, q is 0 or 1, each R ³ is independently selected from H or a substituent, each R ⁴ is independently selected from H or a substituent, R ³ and / or R ⁴ Is optionally substituted phenyl,
Here, when R ⁴ is not H, R ⁴ and (Ar) _m may be linked by a direct bond or a divalent group, and when R ³ is not H, R ³ and (Ar) _n are May be linked by a direct bond or a divalent group, and when n or m is at least 2, the adjacent Ar group may be linked by a divalent group, provided that q = 0 , R ³ is not H but is linked to (Ar) _n ]. Use of an optionally substituted triplet accepting unit to accept triplet excitons generated by a fluorescent organic light emitting polymer comprising a fluorescent organic light emitting repeat unit and a triplet accepting unit having the formula:

Wherein each Ar independently represents an optionally substituted aryl or heteroaryl group, n is 1-3, and m is independently 1-5 each time it appears. Yes, q is 0 or 1, each R ³ is independently selected from H or a substituent, each R ⁴ is independently selected from H or a substituent, and R ⁴ is not H, R ⁴ and (Ar) _m may be linked by a direct bond or a divalent group, and when R ³ is not H, R ³ and (Ar) _n are linked by a direct bond or a divalent group. And when n or m is at least 2, adjacent Ar groups may be linked by a divalent group, provided that when q = 0, R ³ is not H and (Ar ) _n is connected to, and at least one Ar group is halogen; cyano Alkyl (s C atoms which non-adjacent, O, S, substituted N, may be replaced by C = O and -COO-); and _{^{- (Ar 4) z (Ar}} 4 is the emergence Each independently selected from optionally substituted aryl or heteroaryl, wherein z is at least 1 and when z is greater than 1, a plurality of Ar ⁴ groups are linked to form an Ar ⁴ group Substituted with at least one substituent selected from: can form a straight chain or branched chain]. 25. Use according to claim 23 or 24, wherein the optionally substituted triplet accepting unit quenches triplet excitons generated by the fluorescent organic light emitting polymer. 26. An optionally substituted triplet acceptor unit mediates triplet-triplet annihilation of a triplet exciton transferred from a fluorescent organic light emitting repeat unit to a triplet acceptor repeat unit. Use as described in.