发光波长可调的聚吡咯甲烷的制备及光学特性

聚合物发光材料因其拥有诸多优点,在有机发光二极管器件方面的应用前景广阔。然而,对于蓝光聚合物发光材料,由于其发光性能、使用寿命等方面仍然存在不足,难以满足全色显示的需要。以吡咯类单体和4-乙基苯甲醛单体为原料,采用溶液缩聚法制备了3种聚吡咯甲烷(聚{吡咯-[2,5-二(4-乙基苯甲烷)]}(PPE)、聚{N-甲基吡咯-[2,5-二(4-乙基苯甲烷)]}(PNPE)和聚{3-乙酰吡咯-[2,5-二(4-乙基苯甲烷)]}(PAPE)),并利用红外光谱、X射线衍射谱、热分析、紫外-可见光谱和荧光光谱等方法分别对其化学结构、聚集态结构、热性能、紫外-可见吸收行为和发光性能等进行了表征。研究结果表明,PPE、PAPE及PNPE在350 nm左右的紫外光的激发下,分别产生约为474 nm、455 nm及422 nm的可见发射光,对应为蓝色及蓝紫色的发光材料,且聚吡咯甲烷分子中吡咯环上的取代基对其发光性能的影响较大。通过对聚吡咯甲烷进行结构设计可以调节其发光波长,从而开发具有特定蓝色的发光器件材料。     

Phosphorescent blue organic light-emitting diodes with new bipolar host materials

We report narrow band gap bipolar host materials, CbPr-3 (9,9'-[(3,3'-Biphenyl-3.3'-yl-bipyridine)-1,3-biphenyl]bis-9H-carbazole) and Bim-4 (9,9'-[5-(1-phenyl-1H-benzimadazol-2yl)-1,3-phenylene] bis-9H-carbazole), for blue phosphorescent OLEDs application. These two bipolar hosts have high triplet energy of > 2.9 eV, capable of reducing the driving voltages and improving efficiencies. Significant low driving voltages of 7.4 and 6.6 V were obtained for CbPr-3 and Bim-4 hosts, compared with 9.0 V of the commonly used host, mCP (1,3-bis(9-carbazolyl)benzene). At a given constant luminance of 1000 cd/m2, the power efficiency of both the bipolar host devices was enhanced by 2.5 times.     

Adamantyl Substitution Strategy for Realizing Solution‐Processable Thermally Stable Deep‐Blue Thermally Activated Delayed Fluorescence Materials

Highly efficient solution‐processable emitters, especially deep‐blue emitters, are greatly desired to develop low‐cost and low‐energy‐consumption organic light‐emitting diodes (OLEDs). A recently developed class of potentially metal‐free emitters, thermally activated delayed fluorescence (TADF) materials, are promising candidates, but solution‐processable TADF materials with efficient blue emissions are not well investigated. In this study, first the requirements for the design of efficient deep‐blue TADF materials are clarified, on the basis of which, adamantyl‐substituted TADF molecules are developed. The substitution not only endows high solubility and excellent thermal stability but also has a critical impact on the molecular orbitals, by pushing up the lowest unoccupied molecular orbital energy and triplet energy of the molecules. In the application to OLEDs, an external quantum efficiency (EQE) of 22.1% with blue emission having Commission Internationale de l'Eclairage (CIE) coordinates of (0.15, 0.19) is realized. A much deeper blue emission with CIE (0.15, 0.13) is also achieved, with an EQE of 11.2%. These efficiencies are the best yet among solution‐processed TADF OLEDs of CIE y < 0.20 and y < 0.15, as far as known. This work demonstrates the validity of adamantyl substitution and paves a pathway for straightforward realization of solution‐processable efficient deep‐blue TADF emitters.     

High efficiency in blue organic light-emitting diodes using an anthracene-based emitting material

A highly efficient deep blue emitting material based on anthracene core structure, 9,10-bis-[4-(2-(4-naphthalene-1-yl-phenyl)-vinyl)-phenyl]anthracene (NSA), was synthesized and the device performances of blue organic light-emitting diodes (OLEDs) with NSA as an emitting material were investigated. High efficiency value of 7.75 Candela (cd)/A was obtained in NSA blue devices compared with 3.6 cd/A of 9,10-bis(4-(2,2-diphenylvinyl)phenyl anthracene devices. The introduction of a phenylanthracene core and a rigid naphthylphenyl side group gave high thermal stability due to non-coplanar structure and limited intermolecular interactions, resulting in high efficiency in blue OLEDs.     

Efficient phosphorescent green and red organic light-emitting diodes based on the novel carbazole-type host material

We developed a novel carbazole-type material, 9-phenyl-3,6-bis(4-(1-phenyl-1H-benzo[d]imidazol-2-yl)phenyl)-9H-carbazole (LPGH 153), and fabricated the green and red phosphorescent organic light-emitting diodes (OLEDs) using LPGH 153 as host. The red and green devices have the max. luminous efficiencies of 22.2 cd/A and 32.2 cd/A, respectively.     

Aldehyde-functionalized, water-soluble poly(para-phenylene): synthesis and streptavidin assay using FRET

We have attempted to synthesize water-soluble poly(para-phenylene) derivative, poly{[2,5-bis(3-sulfonatobutoxy)-1,4-phenylene sodium salt]-alt-(1,4-phenylene)} (PPP-SO3). Aldehyde groups, versatile functional intermediate groups for immobilization of biomolecules, were introduced at both ends of PPP-SO3 chain to produce PPP-SO3-CHO. PPP-SO3-CHO showed good solubility in aqueous solution and blue emission color, which was expected as an energy donor in FRET mechanism. Biotin was attached to the polymer end groups via imine linkage to use as a ligand for streptavidin immobilization. The biotin coupled with polymer chain enables the polymer to bind with FITC-streptavidin leading to energy transfer from the blue-emitting polymer to green-emitting FITC via FRET.     

A free-standing poly(9-(6-(thiophene-3-yl)hexyl)-9H-carbazole) films: electrosyntheses from a novel carbazole monomer bearing thiophene moiety

The pursuit for the electrosyntheses of high quality polycarbazole (PCz) films is a great challenge for the application of polycabazoles. The incorporation of thiophene unit into carbazole monomer might result in a novel polymer having both the advantages of polythiophene and polycarbazole. As expected in this paper, a novel conducting polymer, free-standing poly(9-(6-(thiophene-3-yl)hexyl)-9H-carbazole) (PTh-H-Cz) films with electrical conductivity of 7.8 S/cm, were synthesized electrochemically by direct anodic oxidation of a novel carbazole monomer, 9-(6-(thiophene-3-yl)hexyl)-9H-carbazole (Th-H-Cz), in boron trifluoride diethyl etherate (BFEE) solution. Incorporation of thiophene unit into carbazole monomer as a pendant led to the electrodeposition of high quality PCz films with metallic shine. Fluorescence spectral study revealed that as-formed polymer film in solid state was a good blue light emitter with strong emission at about 410 nm. This high quality free-standing PTh-H-Cz film will facilitate their potential applications as blue-light-emitting materials in organic light-emitting dioxide.     

茚修饰的蒽类荧光材料的合成及性能

合成了一种茚修饰的蒽类衍生物(INAN)——9,10-二[4-(1,1-二甲基-3-苯基-1H-茚)苯基]蒽,经核磁共振氢谱、碳谱以及高分辨质谱等手段表征了其结构。应用紫外-可见吸收光谱、荧光光谱、循环伏安法和热重分析研究了其光物理、电化学和热稳定性能,计算了其HOMO、LUMO能级和电化学能隙。并将其与工业应用的9,10-二(4-(2,2-二苯乙烯基)苯)蒽进行性能比对,发现该材料的荧光发生蓝移,同时在热稳定性和发光量子产率上均有改善。该类化合物可作为高效的蓝光荧光材料,应用于有机电致发光材料及生物显像等领域。     

The new iridium complexes involving pyridylpyridine derivatives for the saturated blue emission

To obtain a saturated blue phosphorescent material with a good color purity, we have synthesized the new blue emitting iridium complexes with 2, 6-difluoro-3-(4-methylpyridin-2-yl)pyridine (4-Me-dfpypy) as a main ligand. We expected that the LUMO energy levels of the complex might increase upon introduction of an electron donating group such as a methyl group to the pyridyl moieties of the ligand, leading to a wide energy gap of the complex to give the saturated blue emission. We have also introduced a variety of the ancillary ligands to the iridium center to compare the effect of the ancillary ligards on the emission of their complexes. The resulting iridium complexes, Ir(4-Me-dfpypy)3, Ir(4-Me-dfpypy)2(acac), Ir(4-Me-dfpypy)2(pic) and Ir(4-Me-dfpypy)2(trzl-CH3) where acac, pic, and trzl-CH3 represent acetylacetonate, picolinate, and 2-(5-methyl-2H-1,2,4-triazol-3-yl) pyridinate, respectively exhibited the blue emission at 451, 447, 440 and 425 nm in CH2Cl2 solution. The organic light emitting device (OLED) employing homoleptic Ir(4-Me-dfpypy), as the blue dopant was prepared and their electroluminescence was investigated. Ir(4-Me-dfpypy)3 exhibited the blue emission of CIE coordinates (0.22, 0.32).     

Color combination of conductive polymers for black electrochromism

Conducting polymers that absorb three primary colors, red, green, and blue (RGB), were introduced with a yellow electrochromic polymer (Y) for the preparation of black electrochromic devices. Red poly(3-hexylthiophene) (P3HT) and blue poly(3,4-ethylenedioxythiophene) (PEDOT) were coated on one side of the electrode as a cathodically coloring electrochromic (EC) layer, while green poly(aniline-N-butylsulfonate) (PANBS) and yellow EC poly{[1,3-bis(9',9'-dihexylfluoren-20-yl)azulenyl]-alt-[2",7"-(9",9"-dihexylfluorenyl]} (PDHFA) were coated on the opposite electrode to complete a complementary EC device. The yellow PDHFA layer effectively compensated for absorption below 450 nm and above the 600 nm region, which was lacking in the RGB electrode. The resultant RGBY ECD provided a black color near the CIE black with L*, a*, and b* values of 32, -1.1, and 3.7, respectively, covering a broad absorption in the visible range in the colored state. The state of the black EC device was maintained, even after the electricity was turned off for 200 h, showing stable memory effect.     

Organic light emitting diodes based on dipyridamole drug

The dipyridamole drug [DIP: 2,6-bis(diethanolamino)-4,8-dipiperidinopyrimido(5,4-d)pyrimidine] is widely used in treatment of coronary heart disease for its antiplatelet and vasodilating activities, and its high intensity photoluminescence (PL) has been widely reported. In this work, the fabrication and the characterization of a new OLED using the DIP molecule as an emitting layer is reported. The devices were assembled using a heterojunction between three organic molecular materials: the N,N′-bis(naphthalen-1-yl)-N,N′-bis(phenyl)benzidine (NPB) or the 1-(3-methylphenyl)-1,2,3,4-tetrahydroquinoline-6-carboxyaldehyde-1,1′-diphenylhydrazone (MTCD) as hole-transporting layer, the DIP layer as an emitting layer and the tris(8-hydroxyquinoline aluminum) (Alq₃) as the electron transporting layer. All the organic layers were sequentially deposited in a high vacuum by thermal evaporation onto indium tin oxide substrates and without breaking vacuum. Continuous electroluminescence emission was obtained in all configurations upon varying the applied bias voltage from 4 to 30 V, the observed wide emission band was centered at 493 nm. The luminance of the devices was about 1500 (cd)/m² with 4.5 cd/A of efficiency for the best device. The charge transport behavior in the OLED is also discussed as a function of different carrier injection levels.     

Efficient deep-blue organic light-emitting diodes with a 1,4-(dinaphthalen-2-yl)-naphthalene

Deep-blue organic light-emitting diodes (OLEDs) with nearly 5% external quantum efficiency were demonstrated using a 1,4-(dinaphthalen-2-yl)-naphthalene (DNN) host. The 4,4'-bis(9-ethyl-3-carbazovinylene)-1,1'-biphenyl (BCzVBi) dopant that was used in this experiment effectively accepted energy from the DNN host via F?rster energy transfer because the photoluminescence spectrum of the DNN host showed better spectra overlap with the ultraviolet-visible (UV-vis) absorption spectrum of the BCzVBi dopant than the photoluminescence spectrum of the 2-methyl-9,10-bis(naphthalen-2-yl)anthracene host did. Moreover, the DNN host had a higher energy bandgap (3.5 eV) than the BCzVBi dopant did (3.0 eV), while the MADN host had the same energy bandgap as the BCzVBi dopant. The optimized deep-blue device also had ETL of bis-(2-methyl-8-quinolinolate)-4-(phenylphenolato)aluminium which showed smoother sigma of 0.6 nm and higher Tg of 92 degrees than those of 4,7-diphenyl-1,10-phenanthroline (14.8 nm and 62 degrees C). The deep-blue device exhibited a peak current efficiency of 5.68 cd/A, a peak external quantum efficiency of 4.89%, and Commission Internationale d' Eclairage coordinates of (0.15, 0.13).     

High efficiency simple white phosphorescent organic light-emitting diodes using a phosphine oxide host

Highly efficient simple white organic light-emitting diodes (WOLEDs) were fabricated using a mixed host of 1,1-bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC) and 2,7-bis(diphenylphosphoryl)-9,9'-spirobi[fluorene] (SPPO13) in the light-emitting layer. A two layer WOLED structure of TAPC hole transport layer and TAPC:SPPO13 emitting layer was developed. Red and blue phosphorescent emitters were doped in the TAPC:SPPO13 mixed host emitting layer and a high quantum efficiency of 16.0% was obtained. In addition, the maximum power efficiency of the WOLEDs was 37.5 Im/W and color coordinate was (0.43, 0.41). The color coordinate could be kept stable irrespective of the luminance of the device.     

New deep blue emitting materials based on indenopyrazine core with high thermal stability

New deep blue emitting materials 2,8-bis(3,5-diphenylphenyl)-6,6,12,12-tetraethyl-6,12-dihydrodiindeno[1,2-b:1',2'-e]pyrazine (DPP-EPY) and 2,8-bis(3',5'-diphenylbiphenyl-4-yl)-6,6,12,12-tetraethyl-6,12-dihydrodiindeno[1,2-b:1',2'-e]pyrazine (DPBP-EPY) were synthesized through introduction of m-terphenyl or triphenylbenzene bulky side groups in a new indenopyrazine core. These materials all showed high thermal stability and highly reduced intermolecular interaction. DPP-EPY and DPBP-EPY showed PL maxima of 456 nm and 460 nm in deep blue region and narrow PL spectra with full-width at half-maximum (FWHM) of 46 nm and 52 nm, respectively. As a result of making non-doped OLED devices using these synthesized materials as emitting layers, DPP-EPY showed EL spectrum of 452 nm, very narrow FWHM of 46 nm, luminance efficiency of 1.04 cd/A with current density of 10 mA/cm2 and CIE coordinate of (0.161, 0.104), creating a deep blue OLED close to the National Television System Committee (NTSC) blue standard.     

9,9-二(丙酸二甲氨基乙酯)芴共聚物的合成及荧光性能

采用迈克尔加成反应制备了单体2,7-二溴-9,9-二(丙酸二甲氨基乙酯)芴(FDMAEA);采用Suzuki偶合反应制备了不同FDMAEA结构单元含量的醇溶性9,9-二(丙酸二甲氨基乙酯)芴-9,9-二辛基芴共聚物(PFDMAEA)。通过核磁共振、凝胶渗透色谱、溶解性测试、紫外-可见光光谱、荧光发射光谱等对其进行了分析研究。结果表明,成功合成了2,7-二溴-9,9-二(丙酸二甲氨基乙酯)芴及9,9-二(丙酸二甲氨基乙酯)芴-9,9-二辛基芴共聚物。该共聚物在极性溶剂,如甲醇中具有良好的溶解性。由于含有DMAEA支链的PFDMAEA主链容易扭曲,共轭长度变短,共聚物的紫外吸收光谱和荧光光谱随着FDMAEA含量的增加而发生蓝移。荧光发光光谱研究表明,溶剂的极性、溶液的浓度、温度和pH值对共聚物的发光性能有很大的影响。随着溶剂极性增大,共聚物的荧光发射强度不断增加。荧光发射强度随溶液浓度的增加先增加后降低,随着溶液温度的上升而降低。当溶液pH值由1增大到14时,荧光强度不断降低,直至淬灭。     

Efficient fluorescent red, green, and blue organic light-emitting devices with a blue host of spirobifluorene derivative

Efficient fluorescent blue, green, and red (RGB) organic light-emitting devices (OLEDs) were fabricated using a blue host material of pyrimidine-containing spirobifluorene derivative 2,7-bis[2-(4-tert-butylphenyl)pyrimidine-5-yl]-9,9′-spirobifluorene (TBPSF) doped with blue dye perylene, green dye 10-(2-benzothiazolyl)-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H,11H-benzo[l] pyrano[6,7,8-ij] quinolizin-11-one (C545T), and red dye 4-(dicyanomethylene)-2-t-butyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB), respectively. The brightness and current efficiency of the perylene doped blue device reached 10117 cd/m² and 2.97 cd/A. Green emission of the C545T doped device reached 8500 cd/m² and 13.0 cd/A. Red emission of the DCJTB doped device can be as high as 9000 cd/m² and 2.0 cd/A, respectively. High color purity of the blue (Commission Internationale de L′Eclairage (CIE_x,y) coordinates (CIE, x = 0.27, y = 0.24)), green (CIE, x = 0.19, y = 0.63) and red (CIE, x = 0.62, y = 0.37) emissions were achieved for RGB dyes doped TBPSF OLEDs. High brightness, large current efficiency, and good color purity of TBPSF-based RGB OLEDs were obtained by the configuration optimization device, such as inserting the hole and electron-injection materials, and suitable dopant content and light emitting layer thickness.     

The preparation of YBCO epitaxial superconducting films by a chemical solution deposition process

The utility of a chemical precursor solution for the production of YBa₂Cu₃O_7-x superconducting films has been investigated. The homogeneous precursor solution made of metal acetates, 1,3-bis(dimethylamino) -2-propanol, and acetic acid was applied to [1 0 0] MgO substrates via spin-coating. Subsequent heating and sintering removed the organic components. The best epitaxial film obtained by this chemical solution deposition method has a T_c of 78 K.     

White organic light-emitting diodes from three emitter layers

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) (Alq₃) 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/m². The external quantum and power efficiency at a luminance of approximately 100 cd/m² were 2.62% and 3.04 lm/W, respectively.     

Second-order hyperpolarizability and nonlinear optical properties of novel organic compound-doped poly (O-methoxyaniline) polymer film

Journal of Materials Science: Materials in Electronics - The structural characterization of a new organic compound (3, 5-bis (4-chlorophenyl)-4,5-dihydro-1H-Pyrazole) was analyzed experimentally by...     

Photoelectrocatalytic oxidation of remazol turquoise blue and toxicological assessment of its oxidation products

The ability of photoelectrocatalytic oxidation to degrade the commercially important copper-phtalocyanine dye, remazol turquoise blue 15 (RTB) was investigated. The best experimental condition was optimized, evaluating the performance of Ti/TiO2 thin-film electrodes prepared by sol-gel method in the decolourization of 32 mg L(-1) RTB dye in 0.5 mol L(-1) Na2SO4 pH 8 and applied potential of +1.5 V versus SCE under UV irradiation. Spectrophotometric measurements, high performance liquid chromatography, dissolved organic carbon (TOC) evaluation and stripping analysis of yielding solution obtained after 3 h of photoelectrolysis leads to 100% of absorbance removal from wavelength of 250-800 nm, 79.6% of TOC reduction and the releasing of up to 54.6% dye-bound copper (0.85 mg L(-1)) into the solution. Both, original and oxidized dye solution did not presented mutagenic activity with the strains TA98 and TA100 of Salmonella in the presence and absence of S9 mix at the tested doses. Nevertheless, the yielding photoelectrocatalytic oxidized solution showed an increase in the acute toxicity for Vibrio fischeri bacteria, explained by copper liberation during treatment.