Abstract  Bismuth Trifluoride (BiF3), with a high thermal stability and a low deposition temperature, ;has been studied as a novel dopant for the conventional hole transporting material of N,N'-di(naphthalene-1-yl)-N,N'-diphenyl-benzidine (NPB). The efficiency and lifetime of organic light-emitting diodes (OLEDs) have been remarkably improved by using BiF3 doped NPB. For an optimized green device, a current efficiency of 21.6 cd/A is reached, 40% higher than the control device without BiF3. And the lifetime is increased from 115 h to 222 h at room temperature. The enhanced efficiency and lifetime are attributed to the improved balance of holes and electrons in the emissive layer. Most importantly, the thermal stability at an elevated temperature of the OLEDs with BiF3 doped NPB is largely improved, showing an order of magnitude longer lifetime than the control device at 80 degrees C. (C) 2014 Elsevier B.V. All rights reserved.

Abstract  Twenty-one benchmark soils of the United States, including surface and subsurface horizons and satellites, from the Water Erosion Prediction Project (WEPP) were analyzed for phosphorus (P), using methods that include total (TP), water-soluble (WP), Bray 1 (BP), Mehlich No. 3 (MP), Olsen (OLP), New Zealand P Retention (NZP), organic (OP), anion exchange resin (AEP), and acid oxalate (P-o). Objectives of this study were to determine relationships among soil P test values and other soil properties. Knowledge and understanding of these relationships are important to researchers when evaluating soil P data sets for use in predictive models for agronomic, soil genesis, or environmental purposes. Important relationships that were developed, using simple or multiple linear regression models, among P methods and other soil properties, e.g., organic carbon (OC), total N (TN), dithionite-citrate extractable iron and aluminum (Fe-d, Al-d), and clay are as follows: TP (mg/kg) = 229.02 + 27.76 Al-d (g/kg) + 27.44 OC (g/kg) + 4.14 Fe-d (g/kg), r(2) = 0.89, p < 0.01, n = 263 (all soils) OP (mg/kg) = 114.07 + 38.07 TN (g/kg) - 14.74 pH + 6.94 OC (g/kg), r(2) = 0.80, p < 0.01, n = 262 (all soils) BP (mg/kg) = -1.82 + 1.11 MP (mg/kg), r(2) = 0.96, p < 0.01, n = 268 (all soils) P-o (mg/kg) = 16.02 - 24.27 Al-o (g/kg) + 25.59 Fe-o (g/kg) + 19.33 OC (g/kg)r(2) = 0.79, p < 0.01, n = 203 (non-calcareous) NZP (%) = 16.92 + 1.37 Al-d (g/kg) + 0.28 clay (%), r(2) = 0.91, p < 0.01, n = 203 (non-calcareous).

Abstract  A blue, organic, light-emitting diode (OLED) has been made from a new blue emitting material. The structure of the blue device is indium tin oxide (ITO)/CuPc/NPB/JBEM:perylene/Alq/MgAg. Here copper phthalocyanine (CuPc) is used as a buffer layer, N,N'-bis-(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine (NPB) as the hole transporting layer, 9,10-bis(3'5'-diaryl)phenyl anthracene (JBEM) as the blue emitting host, perylene as the blue dopant, Tris(8-guinolinolato) aluminium complex (Alq) as the electron transporting material, and M-Ag alloy as the cathode. The blue device has a maximum luminance of 7526 cd/m(2), and the luminance at a cut-rent density of 20 mA/cm(2) is 408 cd/m(2). It has a maximum efficiency of 1.45 lm/W., Commission Internationale de l'Eclairage (CIE) co-ordinates x = 0.14, y = 0.21, and a half-life of 1035 h at initial luminance of 100 cd/m(2). It shows a better stability than the blue device from distyrylarylene derivatives as the blue emitting host, and also perylene as the dopant with the same structure. (C) 2001 Elsevier Science B.V. All rights reserved.

Abstract  An undoped charge-generation unit (CGU) with the structure of lithium fluoride (LiF)/aluminum/molybdenum trioxide (MoO3) was demonstrated in tandem organic light-emitting diodes (OLEDs). Tandem OLEDs with two identical emissive units consisting of 4,4-bis-(1-naphthyl-N-phenylamino)-biphenyl (NPB)/tris(8-hydroxyquinoline) aluminum (Alq(3)) exhibited superior performance over a corresponding single-unit device. Under a driving current of 650Am(-2), the current efficiency of the tandem OLEDs was about 6.95cdA(-1), almost double that of the single-unit OLEDs. The operational stability of the tandem OLEDs was also enhanced compared with that of the single-unit OLEDs. It was demonstrated that the MoO3 plays a critical role of charge generation in this undoped CGU. The LiF/Al layers were used to enhance the electron injection from MoO3 layer to the adjacent Alq(3) layer. Furthermore, fabrication of this CGU involves no sputtering or doping process, which can render tandem OLEDs processing more feasible.

Abstract  A top-emission inverted organic light-emitting diode (TEIOLED) was fabricated by using AI/AlNx layer as the cathode in the device structure of glass/Al/AlNx/AlQ(3)/NPB/MTDATA/Au/Ag, where AlNx ultra-thin layer was obtained from Al layer under 90 W microwave plasma treatments in Ar and N-2 mixed-gas environment. The N-2/Ar ratio and plasma treatment time were adjusted to obtain the maximum luminance and efficiency of 1206 cd/m(2) and 0.51 cd/A, respectively, both at 17 V. The AlNx layer surface after plasma treatment was examined by atomic force microscope (AFM) to study the effects of surface roughness on the electroluminescent (EL) characteristics. The thickness of AlNx layer also affected EL results apparently. (c) 2007 Elsevier B.V. All rights reserved.

Abstract  We have synthesized a series of novel bis-DCM derivatives as candidate red dopants for use in organic light-emitting devices (OLEDs), by introducing various donor-substituted aryl rings. Compared to DCJTB (621 nm), the novel dopants (637-677 nm) showed more red-shifted emission in 1,2-dichloroethane. Using bis-DCMNEtOBu (7) as a dopant, we fabricated OLEDs with the configuration of ITO/4,49,40"-tris(3-methylphenylamino)triphenylamine (m-MTDATA) ( 20 nm)/N,N'-bis(1-naphthyl)-diphenyl-1,1'-biphenyl-4,4'-diamine (NPB) (40 nm)/tris(8-quinolinolato) aluminium (Alq(3)) : red dopant (35 nm, x wt%)/ Alq(3) (35 nm) LiF/Al. The device with a doping concentration of 1.25 wt% showed pure red emission at lambda(max) 5 654 nm ( chromaticity coordinate: x = 0.67, y = 0.33) and a maximum brightness of 2500 cd m(-2). The chromaticity coordinates were almost independent of current density. Moreover, highly efficient red emission ( x = 0.63, y = 0.36) was obtained in the 0.74 wt% doped device. The maximum external quantum efficiency was 4.46% at 7 V, the current efficiency was 3.43 cd A(-1), and the power efficiency was 1.64 lm W-1. The highest brightness of 8300 cd m(-2) was obtained at 19.6 V.

Abstract  Two novel red Ir(III) complexes, (PQ)(2)Ir(Pppy) and (DMPQ)(2)Ir(Pppy), based on 2-phenylquinoline (PQ) and 2-(3,5-dimethylphenyl)quinoline (DMPQ) as cyclometalating ligands and 2-[ 4-(phenyl)phenyl]pyridine (Pppy) as a second cyclometalated ligand were synthesized for use in phosphorescent organic light-emitting diodes (OLEDs). The photoluminescence (PL) of (PQ)(2)Ir(Pppy) and (DMPQ)(2)Ir(Pppy) produces red emissions with maximum emission peaks at 602 and 615 nm, respectively. The highest occupied molecular orbital and lowest unoccupied molecular orbital energy levels of (PQ)(2)Ir(Pppy) and (DMPQ)(2)Ir(Pppy) were -5.15/-2.97 and -5.13/-2.96 eV, respectively. Red phosphorescent organic light-emitting devices were fabricated based on (PQ)(2)Ir(Pppy) or (DMPQ)(2)Ir(Pppy) as red dopants: ITO (50 nm)/PEDOT:PSS (40 nm)/NPB (20 nm)/TCTA (10 nm)/TCTA:TPBi:red dopant (25 nm, 10%)/TPBI (35 nm)/LiF (1 nm)/Al (200 nm). (PQ)(2)Ir(Pppy) and (DMPQ)(2)Ir(Pppy) exhibited a very broad full width at half maximum (FWHM) at around 100 nm in electroluminescent (EL) devices, which makes it suitable for fabricating white OLEDs with high colour quality. Among the these devices, the device fabricated by (DMPQ)(2)Ir(Pppy) of higher PL quantum yields (Phi(pl)) than that of (PQ)(2)Ir(Pppy) showed an EL emission peak at 617 nm and a maximum external quantum efficiency (EQE(max)) of 19.2%. Moreover, a white OLED prepared from (DMPQ)(2)Ir(Pppy) with FIrpic and Ir(ppy)(3) gave the best performance, with an EQE(max) of 21.9%, maximum power efficiency of 24.8 lm W-1, luminous efficiency of 40.2 cd A(-1), and Commission Internationale de L'Eclairage coordinates of (0.39,0.41) at a luminance of 1000 cd m(-2).

Abstract  Three-wavelength white organic light-emitting diodes (WOLEDs) were fabricated using two doped layers, which were obtained by separating the recombination zones into three emitter layers. A sky blue emission originated from the 4,4'-bis(2,2'-diphenylethen-1-yl)biphenyl (DPVBi) layer. A green emission originated from a tris(8-quinolinolato)aluminum (III) (Alq(3)) host doped with a green fluorescent 10-(2-benzothiazolyl)-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H,11H-[1]benzopyrano [6,7,8-ij]-quinolizin-11-one (C545T) dye. An orange emission was obtained from the N, N'-bis(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine (NPB) host doped with a red fluorescent dye, 4-(dicyanomethylene)-2-tert-butyl-6(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB). A white light resulted from the partial excitations of these three emitter layers by controlling the layer thickness and concentration of the fluorescent dyes in each emissive layer simultaneously. The electroluminescent spectrum of the device was not sensitive to the driving voltage of the device. The white light device showed a maximum luminance of approximately 53,000 cd/ m(2). The external quantum and power efficiency at a luminance of approximately 100 cd/m(2) were 2.62% and 3.04 lm/W, respectively. (c) 2006 Elsevier B.V. All rights reserved.

Abstract  Most of the commonly used electron transporting materials in organic light-emitting diodes exhibit interfacial polarization resulting from partially aligned permanent dipole moments of the molecules. This property modifies the internal electric field distribution of the device and therefore enables an earlier flat band condition for the hole transporting side, leading to improved charge carrier injection. Recently, this phenomenon was studied with regard to different materials and degradation effects, however, so far the influence of dilution has not been investigated. In this paper we focus on dipolar doping of the hole transporting material 4,4-bis[N-(1-naphthyl)-N-phenylamino]-biphenyl (NPB) with the polar electron transporting material tris-(8-hydroxyquinolate) aluminum (Alq(3)). Impedance spectroscopy reveals that changes of the hole injection voltage do not scale in a simple linear fashion with the effective thickness of the doped layer. In fact, the measured interfacial polarization reaches a maximum value for a 1:1 blend. Taking the permanent dipole moment of Alq(3) into account, an increasing degree of dipole alignment is found for decreasing Alq(3) concentration. This observation can be explained by the competition between dipole-dipole interactions leading to dimerization and the driving force for vertical orientation of Alq(3) dipoles at the surface of the NPB layer. (C) 2016 Author(s).

Abstract  New high-efficiency blue-light-emitting phosphorescent devices with 300 angstrom-thick emissive layer of N,N'-dicarbazolyl-3,5-benzene [mCP] doped with 10 vol.% bis[(3,5-difluoro-4-cyanophenyl) pyridine] iridium picolinate [FCNIr(pic)] were fabricated with the different treatments of hole and electron transport layers. In the experiments, a single layer of 1,1-bis-(di-4-polyaminophenyl) cyclohexane [TAPC] and a double layer of N,N'-di(1-naphthyl)-N,N'-diphenylbenzidine [NPB] and mCP were used as hole transport layers (HTLs). In addition, 500 A -thick double layers of tris-[3-(3-pyridyl) mesityl] borane [3TPYMB] and 4,7-diphenyl-1,10-phenanthroline [Bphen] were used as electron transport layers (ETLs) with various thickness combination of 3TPYMB/Bphen. Among the fabricated devices, the one using TAPC as an HTL and 3TPYMB(100 angstrom)/Bphen(400 angstrom) as an ETL showed best electroluminescent characteristics with a maximum quantum efficiency of 13.3% and a luminance of 950 cd/m(2) at 10V. The color coordinates were (0.14, 0.22) on the Commission Internationale de I'Eclairage (CIE) chart, and the electroluminescent spectra showed the double-peak emissions at 458nm and 483 nm.

Abstract  Penaeus stylirostris densovirus (PstDV) has caused large economic losses to shrimp farming worldwide. Here, a 1-bp deletion within the nuclear localization signal-encoding sequence of open reading frame 1 (ORF1; NS1) of Australian PstDV was identified as a cause of 199-amino acid shortened NS1 protein and production of a second protein, C-terminal NS1. This mutation is believed to reduce virulence as it strongly modifies the characteristics of NS1, which is responsible for the majority of enzymatic activities in PstDV. This finding supports a hypothesis regarding accommodation of PstDV in Australian prawns in relation to viral genetics. However, a high degree of evolution (1.55 x 10(-3) substitutions/site/year) and genetic variation for the virus was attributable to the viral recombination observed with 10 potential genomic breakpoints identified. With this finding, we suggest that awareness of the emergence of new virulent strains should be increased as a preventative measure against future outbreaks of PstDV in the Australian Indo-Pacific. (C) 2015 Elsevier B.V. All rights reserved.

Abstract  We report simple red phosphorescent devices comprising single layer configuration using a tris[1-phenylisoqunolinato-C2,N] iridium (III) (Ir(piq)(3)) dopant concentration as low as 1 wt.% in mixed host systems. The driving voltage of 5.4 V to reach the brightness of 1000 cd/m(2) in the mixed emitting layer of N,N'-diphenyl-N,N'-bis(1,1'-biphenyl)-4,4'-diamine (NPB) and bis(10-hydroxybenzo[h]quinolinato)beryllium (Bebq(2)) is reported. Maximum current and power efficiency values of 9.44 cd/A and 10.62 lm/W are obtained in this single layer structure PHOLEDs, respectively. It is believed that the direct injection of charge carriers to the organic layer and high carrier mobility therein are the keys to the simplification of the device structure. Crown Copyright (C) 2009 Published by Elsevier B.V. All rights reserved.

Abstract  This study aimed to synthesize novel hole transporting materials (HTMs) with biphenyl derivatives that are di- or tetra-substituted with naphthylphenyl amine groups and/or methoxy groups, and to examine systematically the variations of the properties of the HTMs with the number and location of the substituents. The tetranaphthylphenyl amine-substituted biphenyl-based HTMs T1N and T2N were observed to have better thermal properties than the commercial HTM NPB, with decomposition temperatures above 500 degrees C, and a 10 degrees C higher T(g). In EL devices with ITO/2-TNATA-(60 nm)/HTM(15 nm)/Alq(3)(70 nm)/LiF(1 nm)/Al structures, the disubstituted biphenyl-based HTMs with an asymmetric molecular structure D1N and D2N were found to have inferior luminescence efficiencies when compared to NPB, which has a symmetric molecular structure. However, M1N, which is substituted with a further two methoxy groups, was found to exhibit excellent luminance and power efficiencies, 4.88 cd/A and 1.36 lm/W respectively at 100 mA/cm(2), which are higher by about 147% and 127% respectively than those of NPB (3.30 cd/A and 1.07 lm/W at 100 mA/cm(2)), due to better charge balance.

Abstract  We report the synthesis of new conjugated compounds, 10,10'-Bis(4-tert-butyl-Phenyt)-10H, 10' H-[3,3'] biphenothiazinyl(t-BPBP), 10'-(4-tert-Butyl-Phenyl)- 10' H [ 10, 3'; 7' 10'] terphenothiazine (t-BPTP), 10, 10'-Bis-(4-tert-Butyl-Phenyl)-7,7' diphenothiazyl-10H, 10' H-[3,3'] biphenothiazinyl (t-BPDPBP). The obtained compounds were identified by 1H-NMR, IR and FAB-Mass spectroscopy. All the compounds exhibited high glass transition temperature (T-g) in the range of 118-161 degrees C. The glass transition and crystallization temperature of these materials appear to be rather high among commonly used hole injection material (m-MTDATA). Electro-optical properties were characterized by cyclic voltammetry and photoluminescence spectra. Organic Electro-Luminescence (EL) device with configuration of ITO/t-BPBP (60 nm)/NPB (15 nm)/Alq3 (70 nm)/LiF (1 nm)/Al (200 nm) exhibits a current efficiency 4.53 cd/A and power efficiency of 1.88 lm/W at 10 mA/cm(2) current density. (c) 2005 Elsevier B.V. All rights reserved.

Abstract  Transition-metal oxides (TMOs) are one of the most promising kinds of p-doping materials for organic semiconductors. However, to be compatible with organic materials, low-temperature evaporable TMOs are highly desirable. Rhenium(VII) oxide with a very low melting temperature of only 225 degrees C, which is the lowest among all TMO dopants, is first investigated as a p-dopant in N,N'-bis(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4,4-diamine (NPB). Systematic studies are performed compared with ReO3, a different valence state oxide of rhenium. Hole mobility improvement from 5.38 X 10(-4) to 5.88 x 10(-3) cm(2)/(V s) at an electric field of 3 x 10(5) V/cm is achieved by doping Re2O7 into NPB. Lower valence states of Re species in Re2O7-doped NPB than ReO3 are observed by XPS study, indicating stronger charge transfer between Re2O7 and NPB. Temperature-dependent I-V study reveals lower hole injection barrier of Re2O7 than ReO3 in hole-only devices. Crystallinity of NPB flints is found to be the same before and after doping by XRD study. Absorption spectrum study reveals higher stability of R2O7-doped NPB than ReO3 in air. Hole current is enhanced by three orders of magnitude at 2 V when utilizing both rhenium-oxide-doped NPBs in hole-only devices. OLED devices with both rhenium-oxide-doped NPBs as hole injection layer (HIL) show a similar efficiency of 3.3 Cd/A at 300 mA/cm(2). Also, driving voltage is reduced from 2.6 V for pure NPB to 2.5 and 2.4 V for Re2O7 and ReO3 doped NPB, respectively.

Abstract  Thin films of the material PbSnI4 have been deposited by vacuum evaporation. The electrical conductivity, its activation energy and dielectric breakdown strength have been found to be him thickness dependent for films less than or equal to 5000 Angstrom. Conductivity is by anionic defect motion with an activation energy of 0.320 eV and ionic transference number of 0.995 at room temperature. The ionic transport has been independently verified by an electrochemical cell potential method with the use of the material in an all thin film solid state: battery of the configuration M/PbSnI4/(AgI,Ag) M = n, Pb), giving OCV values close to the thermodynamic theoretical maximum for the formation of MI2 at the anode. (C) 1999 Elsevier Science S.A. All rights reserved.

Abstract  A promising fluorene derivative 9,9-bis{4-[di-(p-biphenyl)aminophenyl]}fluorene (BPAPF) of high glass-transition temperature (T-g = 167 degreesC) was synthesized and assessed as the hole-transporting material (HTM) in electroluminescent devices. Devices of various configurations, such as single-heterojunction, with or without dopant, and double-heterojunction devices were made. Superior performance was observed for devices based on BPAPF as the HTM, relative to that based on NPB (4,4'-bis[N-(1-naphthyl)-N-phenyl-amino]-biphenyl). In particular, with a device structure of ITO/BPAPF/Alq:0.5% quinacridone/Alq/Mg:Ag, a maximum luminance of similar to140,000 cd/m(2) was obtained at 15 V and maximum luminance and external quantum efficiencies of 13.7 cd/A and 4.1%, respectively, were obtained at 5.5 V. (C) 2002 Elsevier Science B.V. All rights reserved.

Abstract  A series of 2-(stilben-4-yl)benzoxazole derivatives (BOXSB-X) was prepared and used as a dopant in the fabrication of organic light-emitting diodes. With a device structure of ITO/NPB/CBP/TPBI:3%BOXSB-X/TPBI/Mg:Ag, where NPB, CBP, and TPBI stand for 4,4 ' -bis[N-( 1-naphthyl)-N-phenyl-amino]-biphenyl, 4,4 ' -dicarbazolyl-1,1 ' -biphenyl, and 2,2 ' ,2 "-(1,3,5-phenylene)tris- [1-phenyl-1H-benzimidazole], respectively, light emission from the dopant was observed under electric bias, presumably due to energy transfer between the host TPBI exciton and the dopant. Bright blue emission with a luminance ranging between 8 000 and 13 000 cd/m(2) was obtained depending on the substituent on the stilbene moiety. However, with a device structure of ITO/NPB/TPBI:3%BOXSB-X/TPBI/Mg:Ag, where no CBP layer was present, the recombination/emission region shifted to the NPB layer except in the device doped with dimethylamino-substituted benzoxazole derivative, in which case the carrier trap mechanism is suggested to be responsible for the emission from the dopant.

Abstract  A series of tert-butylated spirofluorene derivatives incorporating a diphenylaminoaryl-vinyl group was synthesized via the Horner-Wadsworth-Emmons olefination and a Suzuki cross-coupling reaction. To examine the electroluminescent properties of these materials, multilayered OLEDs were fabricated into the following device structure: ITO/DNTPD/NPB/MADN: blue dopant materials 1-14/Alq(3)/Liq/Al. All devices showed efficient blue emission. In particular, one device exhibited highly efficient sky blue emission with a maximum luminance of 25 100 cd m(-2) at 8.5 V, as well as luminous, power and external quantum efficiencies of 9.5 cd A(-1), 5.1 lm W-1 and 6.7% at 20 mA cm(-2), respectively. The peak wavelength of electroluminescence was 458 and 484 nm with CIEx,y coordinates of (0.14, 0.21) at 8.0 V. In addition, a deep blue device with CIEx,y coordinates of (0.15, 0.15) at 8.0 V showed a luminous efficiency and external quantum efficiency of 3.8 cd A(-1) and 3.3% at 20 mA cm(-2), respectively.

Abstract  High efficiency blue PLEDs were fabricated by adding a thin interlayer between PEDT:PSS and emitting polymer layers. Two different cross-linkable alkoxysilane-based interlayer materials, X-NPB and X-PDA, were synthesized based on N,N'-bis(4-methylphenyl)-N,N'-diphenyl-1;4-phenylenediamine (PDA) and N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1-biphenyl-4,4-diamine (NPB) which are well-known OLED HTLs. The devices with configuration of indium tin oxide (ITO)/PEDT:PSS (65 nm)/interlayer (10-20nm)/emitting polymer layer (70nm)BaF2 (2nm)/Ca (50 nm/Al (300 nm),were fabricated by spin coating and thermal evaporation. In this device structure, the cross-linked X-NPB or X-PDA interlayers are:more adherent and mechanically robust as well as impervious to spin coating of next emitting polymer layer. In addition, the devices with these interlayes exhibit a higher luminescence and current efficiency than those without interlayers because interlayers have two functions which are blocking electrons and preventing from severe quenching by PEDT:PSS. (c) 2006 Elsevier B.V. All rights reserved.

Abstract  4 A series of novel arylvinylene substituted phenanthroline derivatives has been synthesised and their application as electron transporting materials in organic light emitting diodes (OLEDs) has been investigated. One particular derivative, namely, 2,9-bis-(2-thiophen-2-yl- vinyl)-[1,10] phenanthroline (C-4) shows significantly lower operating voltage (36% reduction) and increase of power efficiency of up to 83% compared to tris (8-quinolinolato) aluminium (III) (Alq(3)). C4 also shows substantially longer (nearly 6-fold) life-time than bathophenanthroline (BPhen) in blue devices. Doping of C4 with electron donors such as m-MTDATA, alpha-NPB and lithium quinolinolate (Liq) further reduces the turn-on voltage and operating voltage. (C) 2011 Elsevier B.V. All rights reserved.

Abstract  We demonstrate the thermal stability of transition-metal-oxide (molybdenum oxide; MoO3)-doped organic semiconductors. Impedance spectroscopy analysis indicated that thermal deformation of the intrinsic 1,4-bis[N-(1-naphthyl)-N'-phenylamino]-4,4'-diamine (NPB) layer is facilitated when the MoO(3-)doped NPB layer is deposited on the intrinsic NPB layer. The resistance of the intrinsic NPB layer is reduced from 300 k Omega to 3 k Omega after thermal annealing at 100 degrees C for 30 min. Temperature-dependent conductance/angular frequency frequency (G/w-f-T) analysis revealed that the doping efficiency of MoO3, which is represented by the activation energy (E-a), is reduced after the annealing process. (C) 2015 Elsevier B.V. All rights reserved.

Abstract  Efficient top-emitting organic light-emitting diodes were fabricated using copper iodide (CuI) doped 1,4-bis[N-(1-naphthyl)-N'-phenylamino]-4,4'-diamine (NPB) as a hole injection layer and Ir(PPY)(3) doped CBP as the emitting layer. CuI doped NPB layer functions as an efficient p-doped hole injection layer and significantly improves hole injection from a silver bottom electrode. The top-emitting device shows high current efficiency of 69 cd/A with Lambertian emission pattern. The enhanced hole injection is originated from the formation of the charge transfer complex between Cut and NPB. (C) 2008 Elsevier B.V. All rights reserved.

Abstract  We report fully vacuum-processed perovskite solar cells with high open circuit voltage. All the layers in the solar cells including the perovskite active layer, hole extraction layers and electron extraction layers were deposited in the vacuum process. Use of molybdenum oxide (MoO3) as an interfacial layer and N, N'-Di(1-naphthyl)-N, N'-diphenyl-(1,1'-biphenyl)- 4,4'-diamine (NPB) as a hole transport material (HTM) for hole extraction resulted in a high open circuit voltage (V-OC) of 1.12 V. Due to the effective hole extraction and high VOC, the devices showed a maximum power conversion efficiency (PCE) of 13.7%. The vacuum processed perovskite solar cells showed relatively high reproducibility showing the average value of PCE of 11.1%. (C) 2014 Elsevier B.V. All rights reserved.

Abstract  Highly efficient blue electrophosphorscent light emitting diodes with a new host material N,N'-dicarbazolyl-1,4-dimethene-benzene (DCB) were demonstrated. The energy transfer mechanism of the host-guest material system consisting of DCB and bis[(4,6-difluorophenyl)-pyridinato-N,C-2'] (picolinato) Ir(III) (FIrpic) is an exothermic process. The device with a configuration of indium tin oxide/ N,N'-diphenyl-N,N'-bis(1,1'-biphenyl)-4,4'-diamine (NPB)/DCB:FIrpic/4,7-diphenyl-1,10-phenanthroline(BPhen)/Mg:Ag was optimized by adjusting the thickness of emitting layer and the dopant concentration. The device with the 8% (weight ratio) FIrpic and 30 nm emitting layer exhibits the maximum external quantum efficiency and current efficiency of 5.8% and 9.8 cd/A, respectively, at the luminance of 22 cd/m(2) driven at the voltage of 6.0 V. (C) 2004 Elsevier B.V. All rights reserved.