COMPOSITION CONTAINING AMINIUM RADICAL CATION

Abstract

Provided is an organic light-emitting diode comprising a substrate, an anode layer, optionally one or more hole injection layers, one or more hole transport layers, optionally one or more electron blocking layers, an emitting layer, optionally one or more hole blocking layers, optionally one or more electron transport layers, an electron injection layer, and a cathode, wherein either the hole injection layer, or the hole transport layer, or both of the hole injection layer and the hole transport layer, or a layer that functions as both a hole injection layer and a hole transport layer, comprises a polymer that comprises one or more triaryl aminium radical cations having the structure (S1) wherein each of R.sup.11, R.sup.12, R.sup.13, R.sup.14, R.sup.15, R.sup.21, R.sup.22, R.sup.23, R.sup.24, R.sup.25, R.sup.31, R.sup.32, R.sup.33, R.sup.34, and R.sup.35 is independently selected from the group consisting of hydrogen, deuterium halogens, amine groups, hydroxyl groups, sulfonate groups, nitro groups, and organic groups, wherein two or more of R.sup.11, R.sup.12, R.sup.13, R.sup.14, R.sup.15, R.sup.21, R.sup.22, R.sup.23, R.sup.24, R.sup.25, R.sup.31; R.sup.32; R.sup.33 R.sup.34 and R.sup.35 are optionally connected to each other to form a ring structure; wherein one or more of R.sup.11, R.sup.12, R.sup.13, R.sup.14, R.sup.15, R.sup.21, R.sup.22, R.sup.23, R.sup.24, R.sup.25, R.sup.31, R.sup.32, R.sup.33, R.sup.34, and R.sup.35 is covalently bound to the polymer, and wherein A is an anion.

##STR00001##

Claims

1. An organic light-emitting diode comprising an anode layer, optionally one or more hole injection layers, one or more hole transport layers, optionally one or more electron blocking layers, an emitting layer, optionally one or more hole blocking layers, optionally one or more electron transport layers, an electron injection layer, and a cathode, wherein either the hole injection layer, or the hole transport layer, or both of the hole injection layer and the hole transport layer, or a layer that functions as both a hole injection layer and a hole transport layer, comprises a polymer that comprises one or more triaryl aminium radical cations having the structure (S1) ##STR00028## wherein each of R.sup.11, R.sup.12, R.sup.13, R.sup.14, R.sup.15, R.sup.21, R.sup.22, R.sup.23, R.sup.24, R.sup.25, R.sup.31, R.sup.32, R.sup.33, R.sup.34, and R.sup.35 is independently selected from the group consisting of hydrogen, deuterium, halogens, amine groups, hydroxyl groups, sulfonate groups, nitro groups, and organic groups, wherein two or more of R.sup.11, R.sup.12, R.sup.13, R.sup.14, R.sup.15, R.sup.21, R.sup.22, R.sup.23, R.sup.24, R.sup.25, R.sup.31, R.sup.32, R.sup.33, R.sup.34, and R.sup.35 are optionally connected to each other to form a ring structure; wherein one or more of R.sup.11, R.sup.12, R.sup.13, R.sup.14, R.sup.15, R.sup.21, R.sup.22, R.sup.23, R.sup.24, R.sup.25, R.sup.31, R.sup.32, R.sup.33, R.sup.34, and R.sup.35 is covalently bound to the polymer, and wherein A.sup. is an anion.

2. The diode of claim 1, wherein the diode comprises a dual-functional layer that functions as a hole injection layer and a hole transport layer, and wherein the diode does not comprise any additional hole injection layer or hole transport layer, and wherein the dual-functional layer comprises polymer that comprises one or more triaryl aminium radical cations having the structure (S1).

3. The diode of claim 2, wherein the diode additionally comprises one or more electron blocking layers.

4. The diode of claim 1, wherein the polymer is a vinyl polymer or a conjugated polymer.

5. The diode of claim 1, wherein the polymer additionally comprises one or more triaryl amine structures (S2) ##STR00029## wherein each of R.sup.11, R.sup.12, R.sup.13, R.sup.14, R.sup.15, R.sup.21, R.sup.22, R.sup.23, R.sup.24, R.sup.25, R.sup.31, R.sup.32, R.sup.33, R.sup.34, and R.sup.35 is the same as in structure (S1).

6. The diode of claim 5, wherein the mole ratio of structures S2 to structures S1 is from 999:1 to 0.001:1.

7. The diode of claim 5, wherein the diode comprises a gradient layer that is located between the anode layer and the emitting layer and that comprises S1 groups and S2 groups, wherein the mole ratio of S2 groups to S1 groups is not uniform throughout the gradient layer.

8. The diode of claim 7, wherein the mole ratio of S2 groups to S1 groups in the portion of the gradient layer nearest the anode layer is defined as MRA:1, wherein the mole ratio of S2 groups to S1 groups in the portion of the gradient layer nearest the emitting layer is defined as MRE:1, and wherein MRA is less than MRE.

9. The diode of claim 8, wherein the ratio of MRA to MRE is 0.9:1 or less.

10. The diode of claim 1, wherein the composition additionally comprises one or more polymers that have no structure S1.

11. The diode of claim 1, wherein the polymer has number average molecular weight of 2,500 to 300,000 Da.

12. The diode of claim 1, wherein A.sup. is selected from the group consisting of BF.sub.4.sup., PF.sub.6.sup., SbF.sub.6.sup., AsF.sub.6.sup., ClO.sub.4.sup., anions of structure SA, anions of structure MA, and mixtures thereof, wherein the structure SA is ##STR00030## wherein Q is B, Al, or Ga, and wherein each of y1, y2, y3, and y4 is independently 0 to 5, and wherein each R.sup.61 group, each R.sup.62 group, each R.sup.63 group, and each R.sup.641 group is selected independently from the group consisting of deuterium, a halogen, an alkyl, and a halogen-substituted alkyl, and wherein any two groups selected from the R.sup.61 groups, the R.sup.62 groups, the R.sup.63 groups, and the R.sup.641 groups are optionally bonded together to form a ring structure, and wherein the structure MA is ##STR00031## wherein M is B, Al, or Ga, and wherein each of R.sup.62, R.sup.63, R.sup.64, and R.sup.65 is independently alkyl, aryl, fluoroaryl, or fluoroalkyl.

Description

PREPARATIVE EXAMPLE 1: SUMMARY OF SYNTHESIS OF MONOMER S101

[0105] ##STR00025##

PREPARATIVE EXAMPLE 2: SYNTHESIS OF 3-(3-(4-([1,1-BIPHENYL]-4-YL(9,9-DIMETHYL-9H-FLUOREN-2-YL)AMINO)PHENYL)-9H-CARBAZOL-9-YL)BENZALDEHYDE

[0106] A round bottom flask was charged with carbazole (9.10 g, 15.1 mmol, 1.0 equiv), 3-bromobenzaldehyde (2.11 mL, 18.1 mmol, 1.2 equiv), CuI (0.575 g, 3.02 mmol, 0.2 equiv), potassium carbonate (6.26 g, 45.3 mmol, 3.0 equiv), and 18-crown-6 (399 mg, 10 mol %). The flask was flushed with nitrogen and connected to a reflux condenser. 55 mL of dry, degassed, 1,2-dichlorobenzene was added, and the mixture was heated to 180 C. overnight. Only partial conversion was noted after 14 hours. An additional 2.1 mL of 3-bromobenzaldehyde was added, and heated continuously for another 24 hours.

[0107] The solution was cooled and filtered to remove solids. The filtrate was concentrated and adsorbed onto silica for purification by chromatography (0 to 60% dichloromethane in hexanes), which delivered product as a pale yellow solid (8.15 g, 74%). .sup.1H NMR (500 MHz, CDCl.sub.3) 10.13 (s, 1H), 8.39-8.32 (m, 1H), 8.20 (dd, J=7.8, 1.0 Hz, 1H), 8.13 (t, J=1.9 Hz, 1H), 7.99 (d, J=7.5 Hz, 1H), 7.91-7.86 (m, 1H), 7.80 (t, J=7.7 Hz, 1H), 7.70-7.58 (m, 7H), 7.56-7.50 (m, 2H), 7.47-7.37 (m, 6H), 7.36-7.22 (m, 9H), 7.14 (ddd, J=8.2, 2.1, 0.7 Hz, 1H), 1.46 (s, 6H). .sup.13C NMR (126 MHz, CDCl.sub.3) 191.24, 155.15, 153.57, 147.22, 146.99, 146.60, 140.93, 140.60, 139.75, 138.93, 138.84, 138.17, 136.07, 135.13, 134.42, 133.53, 132.74, 130.75, 128.75, 128.49, 127.97, 127.79, 127.58, 126.97, 126.82, 126.64, 126.51, 126.36, 125.36, 124.47, 124.20, 123.94, 123.77, 123.60, 122.47, 120.68, 120.60, 120.54, 119.45, 118.88, 118.48, 109.71, 109.58, 46.88, 27.12.

PREPARATIVE EXAMPLE 3: SYNTHESIS OF N-([1,1-BIPHENYL]-4-YL)-9,9-DIMETHYL-N-(4-(9-(3-VINYLPHENYL)-9H-CARBAZOL-3-YL)PHENYL)-9H-FLUOREN-2-AMINE (S101)

[0108] Under a blanket of nitrogen, a round bottom flask was charged with methyltriphenylphosphonium bromide (14.14 g, 39.58 mmol, 2.00 equiv) and 80 mL dry THF. Potassium tert-butoxide (5.55 g, 49.48 mmol, 2.50 equiv) was added in once portion, and the mixture stirred for 15 minutes. Aldehyde from Preparative Example 2 (13.99 g, 19.79 mmol, 1.00 equiv) was added in 8 mL dry THF. The slurry stirred at room temperature overnight. The solution was diluted with dichloromethane, and filtered through a plug of silica. The pad was rinsed with several portions of dichloromethane.

[0109] The filtrate was adsorbed onto silica and purified by chromatography twice (10 to 30% dichloromethane in hexanes), which delivered product as a white solid (9.66 g, 67%) Purity was raised to 99.7% by reverse phase chromatography. .sup.1H NMR (400 MHz, CDCl.sub.3) 8.35 (d, J=1.7 Hz, 1H), 8.18 (dt, J=7.7, 1.0 Hz, 1H), 7.68-7.39 (m, 19H), 7.34-7.23 (m, 9H), 7.14 (dd, J=8.1, 2.1 Hz, 1H), 6.79 (dd, J=17.6, 10.9 Hz, 1H), 5.82 (d, J=17.6 Hz, 1H), 5.34 (d, J=10.8 Hz, 1H), 1.45 (s, 6H). .sup.13C NMR (101 MHz, CDCl.sub.3) 155.13, 153.57, 147.26, 147.03, 146.44, 141.29, 140.61, 140.13, 139.55, 138.95, 137.99, 136.36, 135.98, 135.06, 134.36, 132.96, 130.03, 128.74, 127.97, 127.77, 126.96, 126.79, 126.63, 126.49, 126.31, 126.11, 125.34, 125.16, 124.67, 124.54, 123.90, 123.55, 123.49, 122.46, 120.67, 120.36, 120.06, 119.44, 118.83, 118.33, 115.27, 110.01, 109.90, 46.87, 27.12.

PREPARATIVE EXAMPLE 4: PROTOCOL FOR RADICAL POLYMERIZATION

[0110] In a glovebox, S101 monomer (1.00 equiv) was dissolved in anisole (electronic grade, 0.25 M). The mixture was heated to 70 C., and AIBN solution (0.20 M in toluene, 5 mol %) was injected. The mixture was stirred until complete consumption of monomer, at least 24 hours (2.5 mol % portions of AIBN solution can be added to complete conversion). The polymer was precipitated with methanol (10x volume of anisole) and isolated by filtration. The filtered solid was rinsed with additional portions of methanol. The filtered solid was re-dissolved in anisole and the precipitation/filtration sequence repeated twice more. The isolated solid was placed in a vacuum oven overnight at 50 C. to remove residual solvent.

PREPARATIVE EXAMPLE 5: MEASUREMENT OF MOLECULAR WEIGHT OF POLYMER

[0111] Gel permeation chromatography (GPC) studies were carried out as follows. 2 mg of HTL polymer was dissolved in 1 mL THF. The solution was filtered through a 0.2 m polytetrafluoroethylene (PTFE) syringe filter and 50 l of the filtrate was injected onto the GPC system. The following analysis conditions were used: Pump: Waters e2695 Separations Modules at a nominal flow rate of 1.0 mL/min; Eluent: Fisher Scientific HPLC grade THF (stabilized); Injector: Waters e2695 Separations Modules; Columns: two 5 m mixed-C columns from Polymer Laboratories Inc., held at 40 C.; Detector: Shodex RI-201 Differential Refractive Index (DRI) Detector; Calibration: 17 polystyrene standard materials from Polymer Laboratories Inc., fit to a 3rd order polynomial curve over the range of 3,742 kg/mol to 0.58 kg/mol.

TABLE-US-00002 Monomer M.sub.n M.sub.w M.sub.z M.sub.z+1 M.sub.w/M.sub.n S101 23,413 88,953 176,978 266,718 3.799 Da Da Da Da

EXAMPLE 6: OXIDATION OF POLYMER

[0112] In a glovebox, the HTL polymer as made in Preparative Example 4 was dissolved in anisole (14 mL/g polymer), and oxidizing agent (Ag(I) tetra(pentafluorophenyl)borate, as described in Inorg. Chem. 2012, 51, 2737-2746) was added in a single portion. After stirring for 24 hours at ambient temperature (approximately 23 C., the solution was filtered through a 0.2 m syringe filter. The material may be used in solution, or the polymer may be precipitated by addition of an excess of methanol. Various polymers were made using various amounts of oxidizing agent, as follows:

TABLE-US-00003 Polymer Equivalents of oxidizing agent Designation per equivalent of monomer p(S101)-00 comparative polymer made in Preparative Example 4 p(S101)-02 0.02 p(S101)-05 0.05 p(S101)-10 0.10

[0113] An alternative method that could be used for oxidizing the polymer is as follows. In a glovebox, a round bottom flask could be charged with the HTL polymer and dichloromethane (50 mL per gram polymer). An equivalent amount of acetonitrile would be added slowly, making sure that precipitation of the substrate did not occur. NOBF.sub.4 (0.0642 M in acetonitrile, 0.1 equiv) would be added dropwise, which would turn the solution deep green. The mixture would be allowed to stir open to the ambient glovebox atmosphere for 30 minutes. Solvent would be removed by vacuum pump.

PREPARATIVE EXAMPLE 7: EXPERIMENTAL PROCEDURES

[0114] Preparation of HTL solution formulation: HTL polymer solid powders were directly dissolved into anisole to make a 2 wt % stock solution. The solution was stirred at 80 C. for 5 to 10 min in N.sub.2 for complete dissolving. The resulting formulation solution was filtered through 0.2 m PTFE syringe filter prior to depositing onto Si wafer.

[0115] Preparation of polymer film: Si wafer was pre-treated by UV-ozone for 2 to 4 min prior to use. Several drops of the above filtered formulation solution were deposited onto the pre-treated Si wafer. The thin film was obtained by spin coating at 500 rpm for 5s and then 2000 rpm for 30s. The resulting film was then transferred into the N.sub.2 purging box. The wet film was prebaked at 100 C. for 1 min to remove most of residual anisole. Subsequently, the film was thermally cross-linked at temperature between 160 C. and 220 C. for a time between 10 and 30 min (details below).

[0116] Strip test on thermally annealed polymer film was performed as follows. The Initial thickness of thermally cross-linked HTL film was measured using an M-2000D ellipsometer (J. A. Woollam Co., Inc.). Then, several drops of o-xylene or anisole were added onto the film to form a puddle. After 90 s, the solvent was spun off at 3500 rpm for 30 s. The Strip thickness of the film was immediately measured using the ellipsometer. The film was then transferred into the N.sub.2 purging box, followed by post-baking at 100 C. for 1 min to remove any swollen solvent in the film. The Final thickness was measured using the ellipsometer. The film thickness was determined using the Cauchy relationship and averaged over 33=9 points in a 1 cm1 cm area. For a fully solvent resistant film, the total film loss (Final-Initial) after strip test should be <1 nm, preferably <0.5 nm.

EXAMPLE 8: STRIP TEST USING O-XYLENE

[0117] Films were made and stripped as described above. Films were annealed for 20 minutes at 150 C. and 180 C. or for 10 minutes at 205 C. and 220 C. Results were as follows:

TABLE-US-00004 o-xylene Film Loss Annealing Times and Temperature 20 min 20 min 10 min 10 min Polymer 150 C. 180 C. 205 C. 220 C. p(S101)-00 13 nm 0 0 0 (comparative) p(S101)-10 19 nm 0 0 0
Annealing at temperature above 150 C. improves the polymer's resistance to stripping by o-xylene. The inventive polymer p(S101)-10 is resistant to stripping by o-xylene when annealed at 180 C. and above.

PREPARATIVE EXAMPLE 9: SYNTHESIS OF S102 AND S103

[0118] Using methods similar to Preparative Examples 1-4, the following monomers were synthesized:

##STR00026##

[0119] Following the procedure in Preparative Example 4, homopolymers p(S102) and p(S103) were formed. Following the procedures in Preparative Example 6, using 0.10 equivalents of oxidizing agent, partially oxidized polymers having aminium radical cations p(S102)-10 and p(S103)-10 were formed. The oxidizing agent was (Ag(I) tetra(pentafluorophenyl)borate.

EXAMPLE 10: CALCULATION OF ORBITAL ENERGIES

[0120] Orbital energies were calculated as follows. The ground-state (S.sub.0) configurations of the molecules were computed using Density Functional Theory (DFT) with hybrid functional (B3LYP) and 6-31 g* basis set. For these closed shell systems (i.e., neutral molecules) the calculations were performed using the restricted approach, whereas for radical cations (open shell system containing an unpaired electron), the calculations were performed using the unrestricted approach. The energies of HOMO (highest occupied molecular orbital), SUMO (singly unoccupied molecular orbital for the radical cation) and LUMO (next unoccupied molecular orbital for the radical cation) were obtained from the ground-state geometries of the neutral molecule and the radical cation. Vibrational analysis on these geometries was performed and the lack of imaginary frequencies helped to ascertain the minima on the potential energy surface (PES). All calculations were performed using G09 suite of programs, as described in Frisch, M. J. T., G. W.; Schlegel, H. B.; Scuseria, G. E.; Robb, M. A.; Cheeseman, J. R.; Montgomery, Jr., J. A.; Vreven, T.; Kudin, K. N.; Burant, J. C.; Millam, J. M.; lyengar, S. S.; Tomasi, J.; Barone, V.; Mennucci, B.; Cossi, M.; Scalmani, G.; Rega, N.; Petersson, G. A.; Nakatsuji, H.; Hada, M.; Ehara, M.; Toyota, K.; Fukuda, R.; Hasegawa, J.; Ishida, M.; Nakajima, T.; Honda, Y.; Kitao, O.; Nakai, H.; Klene, M.; Li, X.; Knox, J. E.; Hratchian, H. P.; Cross, J. B.; Bakken, V.; Adamo, C.; Jaramillo, J.; Gomperts, R.; Stratmann, R. E.; Yazyev, O.; Austin, A. J.; Cammi, R.; Pomelli, C.; Ochterski, J. W.; Ayala, P. Y.; Morokuma, K.; Voth, G. A.; Salvador, P.; Dannenberg, J. J.; Zakrzewski, V. G.; Dapprich, S.; Daniels, A. D.; Strain, M. C.; Farkas, O.; Malick, D. K.; Rabuck, A. D.; Raghavachari, K.; Foresman, J. B.; Ortiz, J. V.; Cui, Q.; Baboul, A. G.; Clifford, S.; Cioslowski, J.; Stefanov, B. B.; Liu, G.; Liashenko, A.; Piskorz, P.; Komaromi, I.; Martin, R. L.; Fox, D. J.; Keith, T.; Al-Laham, M. A.; Peng, C. Y.; Nanayakkara, A.; Challacombe, M.; Gill, P. M. W.; Johnson, B.; Chen, W.; Wong, M. W.; Gonzalez, C.; and Pople, J. A; A.02 ed.; Gaussian Inc.: Wallingford Conn., 2009.

[0121] The orbital energies were as follows:

TABLE-US-00005 Orbital Energies for S101 Molecule.sup.(1) Form Solvent Orbital Energy (eV) S101 neutral anisole HOMO 4.8 S101 neutral toluene HOMO 4.8 S101 neutral anisole LUMO 1.0 S101 neutral anisole LUMO 1.0 S101 neutral anisole triplet 2.6 S101 neutral toluene triplet 2.6 S101 radical cation anisole SUMO 4.9 S101 radical cation toluene SUMO 5.3 S101 radical cation anisole SUMO 4.6 borate S101 radical cation toluene SUMO 4.7 borate S101 radical cation anisole LUMO 2.1 S101 radical cation toluene LUMO 2.5 S101 radical cation anisole LUMO 1.8 borate S101 radical cation toluene LUMO 1.9 borate .sup.(1)Orbital energies were computed for the core structure of S101 without the vinyl group.

TABLE-US-00006 Orbital Energies for S103 Molecule.sup.(2) Form Solvent Orbital Energy (eV) S103 neutral anisole HOMO 4.9 S103 neutral toluene HOMO 4.9 S103 neutral Anisole LUMO 1.0 S103 neutral Toluene LUMO 1.0 S103 neutral Anisole triplet 2.6 S103 neutral Toluene triplet 2.6 S103 radical cation anisole SUMO 5.1 S103 radical cation toluene SUMO 5.51 S103 radical cation anisole SUMO 4.7 borate S103 radical cation toluene SUMO 4.9 borate S103 radical cation anisole LUMO 2.3 S103 radical cation toluene LUMO 2.7 S103 radical cation anisole LUMO 1.9 borate S103 radical cation toluene LUMO 2.1 borate .sup.(2)Orbital energies were computed for the core structure of S103 without the vinyl group.
In both S101 and S103, the SUMO orbital energy of the radical cation is similar to the HOMO orbital energy of the neutral molecule. It is contemplated that this result means that when radical cations are mixed with neutral molecules, the radical cations will be able to act as a p-dopants, thus allowing the mixture to function as an HIL and/or as an HTL. The orbital energies shown in the table above can be used to design device architecture, including the use of specific materials for HIL, HTL, and EBL.

EXAMPLE 11: TESTING OF OLED DEVICES

[0122] OLED devices were constructed as follows. Glass substrates (20 mm15 mm) with pixelated tin-doped indium oxide (ITO) electrodes (Ossila Inc.) were used. The ITO was treated using oxygen plasma. For the HIL and/or HTL, each polymer was individually dissolved in electronic grade anisole (2% w/w) at elevated temperature (<100 C.) to ensure complete dissolution and passed through a 0.2 m PTFE filter. The materials were deposited into a layer by dynamic spin coating whereby 20 L of the solution was dispensed onto a spinning substrate. The spin speed (approximately 2000 RPM) was adjusted for each material to achieve a film thickness of approximately 40 nm. Some portions of the deposited film which covered sections of the electrodes were removed with toluene using a foam swab. The devices were then annealed at 205 C. for 10 minutes on a hot plate in an inert atmosphere. The emitting layer was a host/emitter mixture having 3 mole % emitter (Tris[3-[4-(1,1-dimethylethyl)-2-pyridinyl-N][1,1-biphenyl]-4-yl-C]iridium) in a host (9-(4,6-Diphenyl-2-pyrimidinyl)-9-phenyl-3,3-bi-9H-carbazole).

[0123] The hole blocking layer (HBL), electron transport layer (ETL), and cathode were formed as follows. A 5 nm layer of 5-(4-([1,1-biphenyl]-3-yl)-6-phenyl-1,3,5-triazin-2-yl)-7,7-diphenyl-5,7-dihydroindeno[2,1-b]carbazole as HBL material was deposited by thermal evaporation under high vacuum from an alumina crucible through an active area shadow mask. A 35 nm layer of 2,4-bis(9,9-dimethyl-9H-fluoren-2-yl)-6-(naphthalen-2-yl)-1,3,5-triazine as ETL material was deposited by thermal evaporation under high vacuum from an alumina crucible through an active area shadow mask. A 2 nm layer of lithium quinolate (liq) was deposited by thermal evaporation under high vacuum from an alumina crucible through a cathode shadow mask. A 100 nm layer of aluminum was deposited by thermal evaporation under high vacuum from a graphite crucible through a cathode shadow mask.

[0124] The OLED devices were tested as follows. Current-Voltage-Light (JVL) data was collected on unencapsulated devices inside a N.sub.2 glovebox using a custom-made test board from Ossila Inc. The board contained two components: 1) X100 Xtralien precision testing source, and 2) Smart PV and OLED Board; in combination, these components were used to test OLED devices over a voltage range of 2 V to 7 V at increments of 0.1 V while measuring current and light output. The light output was measured using an eye response photodiode which includes an optical filter that mimics photopic eye sensitivity (Centronic E Series). The devices were placed inside of the testing chamber on the board and covered with the photodiode assembly. Electrical contact was made to the ITO electrodes by a series of spring-actuated gold probes inside of the Smart Board assembly. The photodiode was located at a distance of 3 mm above the ITO substrate. From the JVL data, critical device parameters were determined including the voltage required to reach 1000 cd/m.sup.2 of brightness, the current efficiency (in cd/A) of the OLED at 1000 cd/m.sup.2, and the driving voltage required to reach 10 mA/cm.sup.2 of current in the OLED. A geometric factor was applied to the measured photodiode current to account for distance between the photodiode and the substrate (3 mm) and the relative positioning from each pixel on the substrate.

[0125] The accelerated service lifetime measurement involved the operation of an OLED under a constant current set to achieve an absolute brightness of 15000 cd/m.sup.2 inside of a N.sub.2 glovebox, without encapsulation. The devices were initially measured for their JVL performance. The device current was set to the required value to reach 15000 cd/m.sup.2 of brightness and allowed to operate for a period of 15 minutes. The voltage to achieve the required driving current was allowed to vary throughout the test. The lifetime is the brightness after 15 minutes relative to the starting brightness.

[0126] Materials used were as follows:

p(S104)=a vinyl homopolymer of the following monomer:

##STR00027##

p(S104) was not oxidized and contained no aminium radical.

[0127] The results of the testing were as follows.

TABLE-US-00007 life- Exam- EFF V1000 V10 time ple HIL HTL EBL (%) (V) (V) (%) 13-1 p(S101)-10 p(S104) none 69.3 3.82 4.59 101.7 13-2 p(S102)-10 p(S104) none 71.3 3.83 4.67 100.3 13-3 p(S103)-10 p(S104) none 69.1 3.94 4.96 102.7 13-4 p(S101)-10 none 76.2 3.74 4.65 100.0 13-5 p(S102)-10 none 74.2 3.81 4.61 104.3 13-6 p(S103)-10 none 87.5 3.74 4.63 102.9 13-7 p(S103)-10 p(S103)-00 90.2 4.00 5.23 108.7 EFF = efficiency at brightness of 1000 candela/m.sup.2 (higher values are desired) V1000 = voltage at brightness of 1000 candela/m.sup.2 (lower values are desired) V10 = voltage at current of 10 mA (lower values are desired) Lifetime = 100 (lifetime of example)/(lifetime of Ex. 13-4)

[0128] Each of Examples 13-4, 13-5, and 13-6 had a single layer that served as both HIL and HTL.

[0129] All of the example diodes performed acceptably in all tests. Examples 13-4, 13-5, and 13-6 showed efficiency better than all the other examples. Examples 13-4, 13-5, and 13-6 showed V1000 lower than the other examples.

[0130] In additional tests (not shown), p(S101)-10, p(S102)-10, and p(S103)-10 were shown to perform acceptably when used as the HTL in an OLED.