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We synthesized and characterized blue emitting materials based on indeno-triphenylene derivatives. Multilayer organic light emitting diodes (OLEDs) were fabricated in the following sequence; ITO (180 nm)/N,N'-diphenyl-N,N'-(2-napthyl)-(1,1'-phenyl)-4,4'-diamine (NPB) (50 nm)/Blue emitter (30 nm)/4,7-diphenyl-1,10-phenanthroline (BPhen) (30 nm)/lithium quinolate (Liq)/Al (2 nm/100 nm). Particularly, a device using 14,14-dimethyl-14H-indeno[1,2-b]triphenylene as an emitter showed the efficient emission and exhibited luminous efficiency, power efficiency, and external quantum efficiency of 11.16 cd/A, 6.05 lm/W, 4.30% at 20 mA/cm2, respectively. Also, it exhibited blue emission with the Commission Internationale De L'Énclairage (CIE) coordinates of (0.21, 0.43) at 8.0 V. [ABSTRACT FROM AUTHOR]

We designed and synthesized biindenophenanthrene derivatives for blue fluorescent organic light-emitting diodes (OLEDs) materials to overcome the disadvantages of blue emitter caused by the wide band gap. To demonstrate the electroluminescence (EL) properties, the OLEDs devices were fabricated in the following sequence: indium-tin-oxide (180 nm)/4,4',4"-tris[2-naphthyl(phenyl)amino (30 nm)/4,4'-bis(N-(1-naphthyl)-N-phenylamino) biphenyl (20 nm)/Blue emitting materials (20 nm)/Bathophenanthroline (30 nm)/lithium quinolate (2 nm)/Al (100 nm). Device A that using 13,13,13',13'-tetramethyl-13H,13'H-11,11'-biindeno[1,2-l]phenanthrene in emitting layer showed luminous efficiency, power efficiency, and external quantum efficiency of 1.72 cd/A, 0.58 lm/W, 1.03% at 20 mA/cm2 with Commission Internationale d'Énclairage (CIE) coordinates of (0.15, 0.23) at 8.0 V. [ABSTRACT FROM AUTHOR]

In this study, as the ongoing effort to develop efficient blue OLEDs, two deep blue emitters based on indenoquinoline-substituted anthracene derivatives have been synthesized and characterized. Multilayer organic light emitting diodes were fabricated with the following sequence: indium-tin-oxide (ITO)/4,4',4"-tris[2-naphthyl(phenyl)amino (2-TNATA)/4,4'-bis(N-(1-naphthyl)-N-phenylamino) biphenyl (NPB)/Blue emitting materials/Bathophenanthroline (Bphen)/lithium quinolate (Liq)/Al. All the devices showed efficient blue emissions. Particularly, a device using '2,7,7,13,13-pentamethyl-9-(10-phenylanthracen-9-yl)−7,13-dihydrobenzo[5,6]-s-indaceno[1,2-g] quinoline' as an emitter showed a maximum external quantum efficiency (EQE) of 4.92% with the Commission Internationale De L'Énclairage (CIE) coordinates of (0.15, 0.10) at 8.0 V. [ABSTRACT FROM AUTHOR]

In this study, as a continuous effort for searching efficient blue-emitting materials, we designed and synthesized materials based on indeno[1,2-a]arene. OLED devices using these materials were fabricated in the following sequence; ITO (180 nm)/N,N'-diphenyl-N,N'-(2-napthyl)-(1,1'-phenyl)-4,4'-diamine (NPB) (50 nm)/emitting materials (30 nm)/4,7-diphenyl-1,10-phenanthroline (Bphen) (30 nm)/Liq/Al (2/100 nm). Particularly, a device using 7,7-dimethyl-7H-indeno[1,2-a]pyrene as emitter showed maximum values of luminous efficiency, power efficiency, and external quantum efficiency of 1.10 cd/A, 0.49 lm/W, 1.47% at 20 mA/cm2, respectively with CIE (x,y) coordinates of (0.15, 0.08) at 6.0V. [ABSTRACT FROM AUTHOR]

Imidazole-pyridine derivatives such as 2-(1-phenyl-5-(pyridin-2-yl)-1H-imidazol-4-yl)pyridine were synthesized for the efficient blue light-emitting materials. OLED devices using these materials were fabricated in the following sequence; Indium tin oxide (ITO) (150 nm)/N,N'-diphenyl-N,N'-(2-napthyl)-(1,1'-phenyl)-4,4'-diamine (NPB) (50 nm)/Tris(4-carbazoyl-9-ylphenyl)amine (TCTA) (10 nm)/Blue materials (20 nm)/2,2′,2"-(1,3,5-Benzinetriyl)-tris(1-phenyl-1-H-benzimidazole) (TPBi) (30 nm)/Lithium quinolate (Liq)/Aluminum (Al) (2/100 nm). Particularly, a device using 9,10-dihydro-9,9-dimethyl-10-(4-(1-phenyl-4,5-di(pyridin-2-yl)-1H-imidazol-2-yl)phenyl)acridine as a blue emitter showed maximum values of luminous efficiency, power efficiency, and external quantum efficiency of 0.21 cd/A, 0.10 lm/W, 0.26% at 20 mA/cm2, respectively with the Commission Internationale d'Énclairage (CIE) (x,y) coordinates of (0.19, 0.11) at 6.0 V. [ABSTRACT FROM AUTHOR]

In this research, we designed and synthesized one emitting material based on benzo[q]quinoline derivative via Suzuki cross coupling reaction. Organic Light-Emitting Diodes (OLEDs) device using this material was fabricated in the following sequence; Indium tin oxide (ITO)/4,4',4''-Tris[2-naphthyl(phenyl)amino]triphenylamine (2-TANATA) (30 nm)/N,N'-di(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl)4,4'-diamine (NPB) (20 nm)/emitting material (30 nm)/bathophenanthroline (Bphen) (30 nm)/8-Quinolinolato lithium (Liq) (2 nm)/Al (100nm). This device showed the efficient emission, with a luminous efficiency, a power efficiency, and external quantum efficiency of, and the Commission International de L'Eclairage (CIE) coordinates of 3.32 cd/A, 1.06 lm/W, 1.00% at 20 mA/cm2, and (0.33, 0.56) at 1000 cd/m2, respectively. [ABSTRACT FROM AUTHOR]

We designed and synthesized two blue fluorescent materials based on spiro[9H-fluorene-9, 5′-[5H] indeno[1, 2-b] pyridine via Buchwald-Hartwig amination and Suzuki coupling reaction. To characterize their electroluminescent properties, multilayered organic light emitting diodes (OLEDs) were fabricated with the following device structures: ITO(180 nm)/2-TNATA(60 nm)/NPB(20 nm)/α,β-ADN: 3, 5, or 10 wt% blue dopants (30 nm)/Bphen(30 nm)/Liq(2 nm)/Al(100 nm). All the devices showed blue emissions with high electroluminescent efficiencies. Particularly, a device using 7′-((4-(N,N-diphenyl)-styryl)-4-phenyl)-spiro[9H-fluorene-9, 5′-[5H] indeno[1, 2-b] pyridine] as a dopant material with 10 wt% doping concentration exhibited highly efficient blue emission with an external quantum efficiency of 4.46% at 20 mA/cm2 and the CIE coordinates of (0.18, 0.30) at 1000 cd/m2. In this device, the twisted structural feature of emitter originated from spiro-type core prevented self-quenching and lead to the improved efficiencies even at high doping concentration in the device. [ABSTRACT FROM AUTHOR]

We designed and synthesized two 9,9′-bianthracene derivatives including fluorene and diarylamine moiety to reduce self-aggregations due to the non-planar structural properties and thus improve electroluminescent (EL) performances of devices using them. To investigate their EL properties, multilayer devices were fabricated with following sequences; ITO (180 nm)/ NPB (50 nm)/ blue emitter1or2(30 nm)/ Bphen (30 nm)/ Liq (2 nm)/ Al (100 nm). Particularly, a device using 9,9-diethyl-N,N-diphenyl-7-(10-(10-(9-phenyl-9 H-carbazol-3-yl)anthracen-9-yl)anthracen-9-yl)-9 H-fluoren-2-amine exhibited a luminous efficiency of 2.09 cd/A, a power efficiency of 0.92 lm/W, an external quantum efficiency of 1.72% at 20 mA/cm2, respectively, and CIE coordinates of (0.16,0.22) at 8.0 V. [ABSTRACT FROM PUBLISHER]

As the continuing effort for efficient blue emitting materials, two fluoranthene derivatives containing fluorene and diarylamine moiety are designed and synthesized to develop the highly efficient blue emitters. To investigate their electroluminescent properties, the OLED devices were fabricated as following structure: ITO (180 nm)/ NPB (50 nm)/ blue emitter1or2(30 nm)/ Bphen (30 nm)/ Liq (2 nm)/ Al (100 nm). All devices showed efficient blue emissions. Particularly, a device using material1exhibited efficient blue emission with luminous efficiency of 3.93 cd/A, power efficiency of 1.65 lm/W, external quantum efficiency of 3.20% at 20 mA/cm2, respectively. [ABSTRACT FROM AUTHOR]

To develop the efficient blue emitters for Organic light-emitting diodes (OLEDs), this paper reports the synthesis and electroluminescent properties of diphenylvinylarenes end-capped with diphenylamine groups. Two OLEDs were fabricated in the following sequence: indium-tin-oxide (ITO) /N,N′-di(1-naphthyl)-N,N′-diphenyl-(1,1′-biphenyl)-4,4′-diam-ine (NPB) (50 nm) / Blue emitters (30 nm) / bathophenanthroline (Bphen) (30 nm) / lithium quinolate (Liq) (2 nm) /Al (100 nm). Two devices exhi-bited blue electroluminescence. In particular, a device using 9,9-diethyl-N,N-diphenyl-7-(2,2-diphenylvinyl)-9H-fluoren-2-amine exhibited blue emission with a luminance efficiency, a power efficiency, an external quantum efficiency and Commission Internationale d’Énclairage (CIE) coordinates of 5.48 cd/A, 2.45 lm/W, 2.85% at 20 mA/cm² and (x = 0.17, y = 0.25) at 8.0 V, respectively. [ABSTRACT FROM AUTHOR]

To develop efficient blue emitters, we synthesized a series of 9,9-diethyl-N,N-diphenyl-9H-fluoren-2-amine derivatives end-capped with various aromatics using Suzuki coupling reaction and Buchwald-Hartwig amination. To investigate their electroluminescent properties, multilayer devices were fabricated in following structures: Indium-tin-oxide (ITO) (180 nm)/N,N′-diphenyl-N,N′-(1-napthyl)-(1,1′-phenyl)-4,4′-diamine (NPB) (50 nm)/ blue emitters (30 nm)/ bathophenanthroline (Bphen) (30 nm)/ 8-hydroxyquinolatolithium (Liq) (2 nm)/ Al (100 nm). All devices showed the blue emissions. Particularly, a device using 9,9-diethyl-7-(10-(10-(naphthalen-2-yl)anthracen-9-yl)anthracen-9-yl)-N,N-diphenyl-9H-fluoren-2-amine showed the efficient blue emission with 5.12 cd/A, 2.33 lm/W, and 3.94% of a luminous, power, and external quantum efficiency at 20 mA/cm2, respectively and CIE (x, y) coordinates of (0.15, 0.15) at 6.0 V. [ABSTRACT FROM AUTHOR]

We investigated efficient blue organic light emitting diodes (OLEDs) containing fluorescent and phosphorescent emitters in the emitting layer (EML). We fabricated several hybrid blue OLEDs with different thicknesses or switching positions for the fluorescent and the phosphorescent EMLs using the fluorescent deep blue emitter 1,6-Bis(N-phenyl-p-CN-phenylamino)-pyrenes and the phosphorescent blue emitter iridium(III)bis[(4,6-difluorophenyl)-pyridinato-N,C2]picolinate. The fabricated device E stacked a 20 nm thickness of phosphorescent EML and a 10 nm thickness of fluorescent EML. Hybrid blue OLEDs have many advantages in terms of their electrical characteristics, as they have a lower efficiency roll-off than phosphorescent OLEDs and a higher efficiency than fluorescent OLEDs. [ABSTRACT FROM AUTHOR]

In this study, four blue fluorescent arylenes end-capped with thiophene derivatives have been synthesized. To explore electroluminescent properties of these molecules, multilayer OLEDs device structure of ITO/NPB/EML/BPhen/Al were fabricated. Two multilayer devices, using 3–4, showed the efficient deep blue emissions with CIE x,y of (0.159, 0.092) and (0.151,0.082) at 9.0 V, and the external quantum efficiencies of 1.60 and 0.80%, respectively. A PFVtPh doped-device exhibited the highly efficient blue emission with a maximum luminance of 3480 cd m−2 at 9.0 V, the external quantum efficiency of 5.23%, and CIE x,y of (0.151, 0.185) at 9.0 V. [ABSTRACT FROM AUTHOR]

We synthesize a red fluorescent material, 2-(6,8-di-tert-butyl-2-(4-((3,5-di-tert-buty- lphenyl)(4-(trimethylsilyl)phenyl)amino)styryl)-4H-chromen-4-ylidene)malononitrile (DCCTBPA) using Knoevenagel condensation. To explore the electroluminescent properties of materials multilayered OLEDs were fabricated by employing DCCTBPA as a dopant material. This device showed the luminous and power efficiencies of 0.73 cd/A and 0.31 lm/W at 20 mA/cm2, respectively, with the CIE coordinates of (0.66, 0.34) at 7.0 V. Compared to a device using DCCPA, this device using DCCTBPA showed the improved EL performances due to reducing the molecular aggregation and thus preventing concentration quenching. [ABSTRACT FROM AUTHOR]

A red fluorescent material 4-(1,3-Indanedione-2-yl)-2-(adaman-1-yl)-6-(10-aza-2,3,4, 5,6,7-hexahydronaphtio[1,8-gh]chromen-10(1H)-one-9-enyl)-4H-pyran is synthesized and characterized. In this material, four methyl groups and adamantly group are introduced into DCJTB skeleton to increase steric hindrance between red emitters in the emitting layer of devices and thus improve the EL efficiencies by preventing concentration quenching. In particular, a device doped with this material in the emitting layer exhibits the luminous and power efficiencies of 3.58 cd/A and 1.61 lm/W at 20 mA/cm2, respectively. The CIE coordinates of this device was (0.64, 0.35) at 7.0V. [ABSTRACT FROM AUTHOR]

An efficient red fluorescent compound, 4-(Dicyanomethylene)-2-(1-pentylbicyclo- [2,2,2]oct-4-yl)-6-(1,1,2,2,7,7-hexamethyljulolidyl-9-enyl)-4H-pyran (DCHMJPB) containing two additional methyl groups on julolidine moiety and 1-pentylbicyclo- [2,2,2]octyl group on pyran moiety, was synthesized and characterized. In this red emitter, the bulky groups such as two additional methyl groups and 1-pentylbicyclo- [2,2,2]octyl group were introduced to increase the steric hindrance between the red emitters and prevent concentration quenching. In particular, in an efficient red device containing emitter DCHMJPB as a dopant, a luminous and power efficiency of 3.76 cd/A and 1.97 lm/W was achieved, respectively, at 20 mA/cm2 with the CIE coordinates of (x = 0.56, y = 0.42) at 7.0V. [ABSTRACT FROM PUBLISHER]

A yellow fluorescent material, (2Z)-3-[4,4′′-bis(dimethylamino)-1,1′:4′,1′′-terphenyl-2′-yl]-2-phenylacrylonitrile was synthesized in order to investigate the effect of molecular structure on surface morphology of its thin film and its optoelectronic property. Atomic force microscopy measurment for thin films of 4-(dicyanomethylene)-2-methyl-6-(julolidin-4-yl-vinyl)-4H-pyran, (2Z)-3-[4,4′′-bis(dimethylamino)-1,1′:4′,1′′-terphenyl-2′-yl]-2-phenylacrylonitrile and (2Z,2′Z)-3,3′-[4,4′′-bis(dimethylamino)-1,1′:4′,1′′-terphenyl-2′,5′-diyl]bis(2-phenylacrylonitrile) represented that surface morphology of thin film of a fluorophore was dependent on its molecular structure such as coplanarity and molecular polarity. Surface morphology of thin film of BDAT-P showed much less amorphous than that of ABCV-P. Atomic force microscopy measurment for BDAT-P and ABCV-P was well corresponding to observed optoelectronic properties of them. The luminance of non-doped devices for BDAT-P and ABCV-P was measured to be 31.6 cd/m2 at 6 V and 249 cd/m2 at 6 V, respectively. [ABSTRACT FROM PUBLISHER]

In this study, we synthesized new 2-(2-(4-(diphenylamino)styryl)-4H-chromen-4-ylidene) malononitrile (DCCPA) derivatives with different π-conjugation aromatic spacer groups between the diphenylamine and (chromen-4-ylidene)malononitrile moieties of the DCCPA. To explore the electroluminescence properties of these materials, multilayered OLEDs were fabricated with a device stricture of: Indium Tin Oxide (ITO) (170 nm)/N,N’-diphenyl-N,N’-(1-napthyl)-(1,1’-phenyl)-4,4’-diamine (NPB) (50 nm)/2-methyl-9,10-bis-2-naphthyl anthracene (MADN):Red dopants 1 (5, 10%) (30 nm)/bis-(2-methyl-8-quinolinolato-N1,O8)-(1,1’-biphenyl-4-olato)aluminum (Balq) (30 nm)/Liq (2 nm)/Al (10 nm). A device using Red 1 showed a maximum luminance of 1030 cd/m2 at 10.0 V, with maximum luminous, power, and quantum efficiencies of 0.94 cd/A, 0.54 lm/W, and 1.11%, respectively. The CIE coordinates of this device were (0.61, 0.35) at 7.0 V, a stable color chromaticity at various voltages. [ABSTRACT FROM PUBLISHER]

The authors have demonstrated red organic light-emitting diodes (OLEDs) using a new fluorescent red emitter, 2-(2-(4-pentylbicyclo[2.2.2]octan-1-yl)-6-(2-(1,1,7-trimethyl-7-triphenysiliyllethyl-1,2,3,5,6,7-hexahydropyrido[3,2,1-ij]quinolin-9-yl)vinyl)-4H-pyran-4-ylidene)malononitrile (DCJTPSO), achieved the maximum external quantum efficiency (EQE) of 2.06%, current efficiency (CE) of 3.83 cd/A, and Commision Internationale De L’Eclairage (CIEx,y) coordinates of (0.58, 0.40) at 0.029 mA/cm2 in comparison with control device using 4-(dicyanomethylene)-2-tert-butyl- 6-(1,1,7, 7-tetramethyljulolidin-4-yl-vinyl)- 4H-pyran which showed the maximum EQE of 1.07%, CE of 1.41 cd/A and CIEx,y coordinates of (0.61, 0.38) at 0.11 mA/cm2. This result showed that the high performance of red device using DCJTPSO showed easier electron trapping directly on the emitter molecule. [ABSTRACT FROM PUBLISHER]

This paper reports the synthesis and electroluminescent properties of new red fluorescent materials, 4-(dicyanomethylene)-2-(1,1-dimethyl-7-trimethylsiliyl methyl-julolidyl-9-enyl)-6-(4-pentylbicyclo[2.2.2]octan-1-yl)-4H-pyran (DCJTMS) and 4-(dicyanomethylene)-2-(1,7-bistrimethylsiliylmethyl-julolidyl-9-enyl)-6-(4-pentylbicyclo[2.2.2]octan-1-yl)-4H-pyran (DCJDTMS). In these red emitters, the bulky groups such as trimethylsilane and n-pentyl-bicyclo[2,2,2]octane were introduced into and 4-(dicyanomethylene)-2-methyl-6-[p-(dimethylamino)-styryl]-4H-pyran (DCM) skeleton to increase the steric hindrance between the red emitters and prevent concentration quenching. An OLED device using 4-(dicyanomethylene)-2-(1,7-bis(trimethylsiliylmethyl)-julolidyl-9-enyl)-6-(4-pentylbicyclo[2.2.2]octan-1-yl)-4H-pyran (DCJDTMS) as a dopant exhibited the efficient red emission with a Luminous efficiency, Power efficiency and Commision Internationale De L’Eclairage (CIEx,y) coordinates of 3.66 cd/A, 2.13 lm/W at 20 mA/cm2 and (0.62, 0.38) at 7.0 V, respectively. Compared to device using 4-(dicyanomethylene)-2-(1,1,7,7-tetra-methyljulolidyl-9-enyl)-6-tert-butyl-4H-pyran (DCJTB), the red device using DCJDTMS showed the greatly improved EL efficiency due to the more bulky substituents of compound DCJDTMS. [ABSTRACT FROM PUBLISHER]

A new yellow fluorescent material, (2Z)-3-[4,4''-bis(dimethylamino)-1,1':4',1''-terphenyl-2'-yl]-2-phenylacrylonitrile (BDAT-P), was synthesized for organic light-emitting diodes. This compound has an electron donor-acceptor group which leads to intramolecular charge transfer property. Optoelectronic properties of a device with the structure of ITO/NPB/MADN:BDAT-P (x %)/BPhen/Liq/Al were measured and the measurement demonstrated that the device using BDAT-P as a dopant revealed highly efficient device performance with greenish yellow electroluminescent emission. Maximum luminance of the device was measured to be 18300 (x = 8%), 10880 (x = 12%) and 11810 (x = 16%) cd/m2, respectively. The maximum luminous and quantum efficiency values were observed to be 12.5 (x = 8%), 9.17 (x = 12%) and 12.79 (x = 16%) cd/A, and 3.83 (x = 8%), 2.8 (x = 12%) and 3.81 (x = 16%) %, respectively. The device emitted greenish yellow light corresponding to Commission Internationale de I'Eclairage (CIExy) coordinates of (0.319, 0.569) (x = 8%) and (0.321, 0.569) (x = 12%) and (0.356, 0.578) (x = 16%) at 10 V. [ABSTRACT FROM AUTHOR]

The naphthalene-based blue materials 4,4'-(Dinaphthalen-2-yl)-1,1'-binaphthyl (DNBN) and 1,4-(Dinaphthalen-2-yl)-naphthalene (DNN) were designed and synthesized for OLEDs. A device (non-doped) employing DNN as the emitter exhibited a maximum luminance, luminous efficiency, and external quantum efficiency of 1120 cd/m2, 1.40 cd/A, and 3.83%, respectively. Moreover, its CIE coordinates (0.152, 0.069) are very close to the NTSC blue standard of (0.14, 0.08). In order to improve EL efficiencies, these materials were used as the blue host materials for the blue dopants PFVtPh and PCVtPh. A device 1b (PFVtPh-doped) showed high EL efficiencies of 5.24 cd/A, 2.75 lm/W, and 3.82% at 20 mA/cm2. [ABSTRACT FROM AUTHOR]

Abstract: Efficient orange-red fluorescent compounds, 4-(dicyanomethylene)-2-adamantyl-6-(4-(N-(4-tert-butylphenyl)-N-(3,5-di-tert-butylphenyl)amino)benzene)vinyl-4H-pyran (DCATP) and 2,6-bis[4-(N-(4-tert-butylphenyl)-N-(3,5-di-tert-butylphenyl)amino)benzene]vinyl-4-(dicyanomethylene)-4H-pyran (BDCTP) containing the tert-butylated triphenylamine in donor moieties, were synthesized and characterized. In these red emitters, bulky groups, such as t-butyl group and adamantane were introduced to increase the steric hindrance between the red emitters. In particular, an efficient orange-red device containing the emitter DCATP as a dopant showed a luminous and power efficiency of 6.87cd/A and 2.70lm/W, respectively, at 20mA/cm2 with the CIE coordinates of (0.48, 0.50) at 7.0V. In addition, an efficient red organic light-emitting diode using BDCTP as a dopant exhibited a luminous and power efficiency of 2.30cd/A and 1.31lm/W, respectively, at 20mA/cm2 and CIE coordinates of (0.61, 0.39). [Copyright &y& Elsevier]

Three bispiro-type molecules, 2-(10-phenylanthracen-9-yl)-bispiro(9,10-dihydro-anthracene-9,7′-7′ H -fluorene-10,7″-7″ H -fluorene) ( 1 ), 10-([naphthalen-2-yl]anthracen-9-yl)-bispiro(9,10-dihydro-anthracene-9,7′-7′ H -fluorene-10,7″-7″ H -fluorene) ( 2 ), and 10-([naphthalen-1-yl]anthracen-9-yl)-bispiro(9,10-dihydro-anthracene-9,7′-7′ H -fluorene-10,7″-7″ H -fluorene) ( 3 ), were synthesized by Pt-catalyzed Suzuki coupling reactions. To explore electroluminescence properties of these materials, devices were fabricated with the following structures: Indium-tin-oxide (180 nm)/4,4′-Bis( N -(1-naphthyl)- N -phenylamino)biphenyl (60 nm)/blue emitting materials (30 nm)/Bathophenanthroline (30 nm)/Lithium quinolate (2 nm)/Al (100 nm). Among devices, device using 2-(10-phenylanthracen-9-yl)-bispiro(9,10-dihydro-anthracene-9,7′-7′ H -fluorene-10,7″-7″ H -fluorene) showed the efficient blue emission with a luminous efficiency of 1.57 cd/A, a power efficiency of 1.83 lm/W and an external quantum efficiency of 1.83% at 20 mA/cm 2 , respectively. The CIE coordinates of this device were (0.16, 0.10). [ABSTRACT FROM AUTHOR]

Four 9,9-diethyl- N , N -diphenyl-9 H -fluoren-2-amine substituted anthracene derivatives have been designed and synthesized by Suzuki cross coupling reactions. To explore the electroluminescent properties of these blue materials, multilayer blue organic light-emitting diodes were fabricated in the following device structure: indium tin oxide (180 nm)/ N , N ’-diphenyl- N , N ’-(1-napthyl)-(1,1′-phenyl)-4,4′-diamine (50 nm)/blue emitting materials ( 1 – 4 ) (30 nm)/bathophenanthroline (30 nm)/lithium quinolate (2 nm)/Al (100 nm). All devices appeared excellent deep-blue emissions. Among them, a device exhibited a maximum luminance of 5686 cd/m 2 , the luminous, power and external quantum efficiencies of 5.11 cd/A, 3.79 lm/W, and 4.06% with the Commission International de L'Eclairage coordinates of (0.15, 0.15) at 500 cd/m 2 , respectively. [ABSTRACT FROM AUTHOR]

This study reports the emitting materials based on phenylanthracene-substituted naphthalene derivatives to achieve efficient electroluminescent properties for OLED applications. An OLED device using 4,4′-bis(10-phenylanthracen-9-yl)-1,1′-binaphthalene exhibited the blue emission with the CIE coordinates of (0.19, 0.16) and efficient electroluminescent properties with the luminance, power and external quantum efficiency of 1.70 cd/A, 0.79 lm/W and 1.26% at 20 mA/cm 2 , respectively. Also, the other device using 1,4-bis(10-phenylanthracene-9-yl)naphthalene exhibited white emission with the CIE coordinates of (0.34, 0.43) at 7V, respectively. This device exhibits the luminance, power and external quantum efficiency of 2.22 cd/A, 1.13 lm/W and 0.86% at 20 mA/cm 2 , respectively. [ABSTRACT FROM AUTHOR]

This paper reports the synthesis and electroluminescence properties of new blue-emitting materials based on anthracene-fluorene derivatives with triphenylsilane groups for organic light-emitting diodes. To study the electroluminescence properties, OLEDs were fabricated in the following sequence: ITO/4,4-Bis( N- (1-naphthyl)- N- phenylamino)biphenyl (50 nm)/newly designed blue materials (30 nm)/4,4-bis( N- (1-naphthyl)- N- phenylamino)biphenyl (30 nm)/8-Hydroxyquinolinolato-lithium (2 nm)/Al (100 nm). All devices exhibited blue electroluminescence. In particular, the device using 10-(9,9-dimethyl-2-(triphenylsilyl)-9 H- fluoren-7-yl)-9-(4-(triphenylsilyl)phenyl) anthracene as the emitting material exhibited the deepest blue-emission with CIE coordinates of ( x = 0.15, y = 0.09). Also, the device using (9,9-dimethyl-2-(10-(10-phenylanthracen-9-yl)anthracen-9-yl)-9 H- fluoren-7-yl)triphenylsilane exhibited high luminous, power and quantum efficiencies of 2.53 cd/A, 1.94 lm/W and 1.72% at 20 mA/cm 2 , respectively. [ABSTRACT FROM AUTHOR]

Abstract: We demonstrate blue organic light-emitting diodes (OLEDs) based on a host-dopant system with a dual emitting layer (EML) configuration consisting of variable concentration of fluorescent doped and fixed concentration of phosphorescent doped emitting materials. We also introduce two different device designs by switching the position of the fluorescent and phosphorescent EMLs. Because 4,4'-Bis(2,2-diphenylvinyl)-1,1'-biphenyl (BCzVBi), which is the blue fluorescent dopant, exhibits the highest occupied molecular orbital (HOMO) energy level compared to the neighboring layers, the fluorescent dopant is shown to strongly correlate with hole transport in the fabricated blue OLEDs. In this study, we show how the electrical and optical properties of devices are affected by different doping concentrations due to the hole-transport-related properties of dopant molecules. [Copyright &y& Elsevier]

Abstract: Efficient red fluorescent compounds Red 1 and Red 2 based on bulky bicyclo[2,2,2]octane groups in the pyran moiety and tert-butyl or isopropyl group in the julolidine moiety of the 4-(dicyanomethylene)-2-tert-butyl-6-(1,1,7,7-tetra-methyljulolidyl-9-enyl)-4H-pyran (DCJTB) skeleton were synthesized and characterized. As red-emitting dopants in an Alq3 single-host emitting system, Red 1 and Red 2 exhibited improved color purity and enhanced luminous efficiency compared to DCJTB. Moreover, a device using Red 1 as a dopant in a rubrene–Alq3 co-host emitting system exhibited improved electroluminescence performance with a luminous efficiency and power efficiency of 6.89cd/A and 3.09lm/W at 20mA/cm2, respectively, and CIE x,y coordinates of (x =0.64,y =0.36) at 7.0V, approaching saturated red emission. [Copyright &y& Elsevier]

Abstract: The authors have demonstrated efficient orange-red organic lighting diodes (OLEDs) using a new fluorescent orange-red material, 9,10-bis[4-(di-4-tert-buthylphenylamino)styryl]anthracene (ATBTPA). The optimized orange-red OLED using ATBTPA achieved a maximum external quantum efficiency (EQE) of 3.78%, a current efficiency (CE) of 9.47cd/A, and Commision Internationale de L''Eclairage (CIE x,y ) coordinates of (0.51, and 0.48) at 1.61mA/cm2 in comparison with orange-red OLED using (5,6,11,12)-tetraphenyl-naphthacene (rubrene) which showed a maximum EQE of 1.65%, CE of 4.94cd/A, and CIE x,y coordinates of (0.50, and 0.49) at 0.61mA/cm2, respectively. The optimized orange-red device using ATBTPA showed higher efficiency of two times the orange-red device using rubrene due to the efficient Förster singlet energy transfer from MADN to ATBTPA in comparison with that from MADN to rubrene. This study clearly suggests that ATBTPA is an excellent fluorescent orange-red material for efficient WOLEDs. [Copyright &y& Elsevier]

Abstract: We have designed and synthesized five blue emitters based on diphenylaminofluorenylstyrene emitting core groups. Multilayered OLEDs were fabricated using these materials as dopants in a 2-methyl-9,10-di(naphthen-2-yl)anthracene (MADN) host. One of them in particular a deep blue OLED using dopant 9-[4-(2-diphenylamino-9,9-diethylfluoren-7-yl)phenyl]-9-phenylfluorene (3) at 15% doping concentration exhibited a maximum luminance of 4720cdm−2 at 9.0V, a luminous efficiency of 5.3cdA−1 at 20mAcm−2, a power efficiency of 2.9lmW−1 at 20mAcm−2, an external quantum efficiency of 4.8% at 20mAcm−2, and CIE coordinates (x =0.15, y =0.13) at 8.0V. Furthermore, this deep blue device had very stable CIE coordinates of (x =0.15, y =0.13) that did not vary with doping concentration from 5% to 15%. [Copyright &y& Elsevier]

Abstract: A series of new blue-emitting materials: 2-(10-(naphthalen-2-yl)anthracen-9-yl)pyridine (1); 1-(10-(naphthalen-2-yl)anthracen-9-yl)isoquinoline (2); 9-(3-(10-(naphthalen-2-yl)anthracen-9-yl)phenyl)-9H-carbazole (3); 9-(4-(10-(naphthalen-2-yl)anthracen-9-yl)phenyl)-9H-carbazole (4); 9-(4-(10-(naphthalen-1-yl)anthracen-9-yl)phenyl)-9H-carbazole (5); 9-(4′-(10-(naphthalen-2-yl)anthracen-9-yl)biphenyl-4-yl)-9H-carbazole (6); and 9-(4′-(10-(naphthalen-1-yl)anthracen-9-yl)biphenyl-4-yl)-9H-carbazole (7) were designed and synthesized via the Suzuki cross-coupling reaction. To explore the electroluminescent properties of these materials, multilayer OLEDs were fabricated in the following sequence: ITO/4,4′-bis(N-(1-naphthyl)-N-phenylamino)biphenyl (NPB) (50nm)/blue-emitting materials (1–7) (30nm) /4,7-diphenyl-1,10-phenanthroline (Bphen) (30nm)/lithium quinolate (Liq) (2nm)/Al (100nm). Among those, a device using 6 as an emitter exhibited a high external quantum efficiency of 3.83% (3.20% at 20mA/cm2) with CIE coordinates of (0.152,0.114). In order to improve EL efficiency, 1–7 were used as blue host materials for blue dopant materials 4′-[2-(2-diphenylamino-9,9-diethyl-9H-fluoren-7-yl)vinyl]-p-terphenyl (PFVtPh) and 3-(N-phenylcarbazol)vinyl-p-terphenyl (PCVtPh). Using 1 as a host material for blue dopant material PFVtPh, the resultant device showed high EL efficiencies with 10.35cd/A, 8.77lm/W, and 5.70% (10.24cd/A, 6.06lm/W, and 5.66% at 20mA/cm2). Furthermore, using 4 as a host for the PCVtPh blue dopant, device 4c exhibited efficient deep-blue emissions with a maximum external quantum efficiency of 2.96% and CIE coordinates of (0.154,0.087), very close to the NTSC blue standard of (0.14,0.08). [Copyright &y& Elsevier]

Abstract: A series of diphenylaminofluorene- and phenylcarbazole-derived, blue fluorescent molecules have been synthesized via the Hornor–Wadsworth–Emmons and Suzuki-cross coupling reactions. To explore the electroluminescent properties of these molecules, multilayer devices were fabricated with a structure of ITO/NPB/(1–6) doped in MADN/Bphen/Liq/Al, yielding a device that exhibited highly efficient sky-blue emissions with the luminous efficiency of 11.2cd/A at 20mA/cm2, a power efficiency of 7.35lm/W at 20mA/cm2, and CIE x,y coordinates of (x =0.16, y =0.26) at 8V. Also, a deep blue OLED with CIE x,y coordinates of (x =0.16, y =0.13) at 8V showed a luminous efficiency of 2.13cd/A and power efficiency of 1.20lm/W at 20mA/cm2, respectively. [Copyright &y& Elsevier]

The organic light-emitting devices (OLEDs) based on fluorescence have low efficiencies due to the requirement of spin-symmetry conservation. By using the phosphorescent material, the internal quantum efficiency can reach 100%, compared to 25% in the case of the fluorescent material. Thus, the phosphorescent OLEDs have recently been extensively studied and showed higher internal quantum efficiencies than the conventional OLEDs. In this study, an orange-red electrophosphorescent devices have been fabricated with a new Ir complex, synthesized by coordinating a new electrowithdrawing lignad to (ppy)2 Iracac, as the emitting dopant. It has been investigated the electrical and optical characteristics of the devices fabricated with a structure of ITO/NPB/Ir complex doped in CBP/BCP/Alq3/Li:Al/Al. The device with the Ir complex demonstrated an efficiency of 3.53 cd/A with an initial brightness of 100 cd/m2. The CIE coordinates for devices held at a current density of 1 mA/cm2 were (0.585, 0.410). [Copyright &y& Elsevier]