聚合物电致发光材料与器件(待续)--聚合物发光材料

1990年Burroughes采用聚对苯乙炔(PPV)作为有源层制作聚合物电致发光器件,开创了共轭聚合物科学的新领域,由于聚合物电致发光器件具有制备简单、发光效率和发光亮度高、发光波长易于调节等显著特点,引起了各国的高度重视,大量的共轭聚合物材料成功地应用于电致发光器件,使得电致发光聚合物材料和器件的研究成为近年来最活跃的领域之一.     

聚合物电致发光材料与器件(续完)--聚合物发光材料

1990年Burroughes采用聚对苯乙炔(PPV)作为有源层制作聚合物电致发光器件,开创了共轭聚合物科学的新领域,由于聚合物电致发光器件具有制备简单、发光效率和发光亮度高、发光波长易于调节等显著特点,引起了各国的高度重视,大量的共轭聚合物材料成功地应用于电致发光器件,使得电致发光聚合物材料和器件的研究成为近年来最活跃的领域之一.     

共轭聚合物合成方法的研究

综述了聚芳撑(PPP、PPY、PTP)、聚对苯撑乙炔(PPV)、聚苯胺(PAn)、聚腈(PAZ)几种共轭聚合物的合成方法.并指出了共轭聚合物应用中存在问题及今后的合成方向.     

新型共轭功能材料-超支化聚合物的研究进展

超支化共轭聚合物由子其所具有的良好的非线性光学特性,在功能高分子领域具有广泛的应用前景。重点介绍了超支化共轭材料的主要种类:超支化聚亚乙烯基苯类,超支化聚(β,β-二溴,4-乙炔基)苯乙烯类,超支化聚芳烃(HPA),超支化光学非线性类聚合物,超支化含香豆素类聚合物等,介绍了典型代表聚合物的制备方法和光学特性。     

新型PPV聚合物具有改善的导电性和稳定性

正由于其导电和光学性质,聚对苯撑乙烯类聚合物(PPV)有助于太阳能、传感器技术、发光二极管和其他技术应用的进步。到目前为止,已经使用的OPPVs,其侧基通过氧原子与聚合物的其余部分连接。科学家认为用硫侧基取代氧产生S-PPVs可以进一步改善材料性     

电致发光材料专利信息

电致发光材料及其制备方法和用途;酚基-吡啶硼配合物及其作为电致发光材料的应用;有机电致发光材料稀土铕有机金属配合物的制取方法;颜色可调的聚对苯乙炔类共聚物电致发光材料及其制备与应用;吩噻嗪类聚合物电致发光材料及其制备方法     

聚合物太阳能电池材料的研究进展

近年来聚合物太阳能电池的研究发展迅速。本文介绍了聚合物太阳能电池的原理和有机光伏材料的性能要求,并针对聚噻吩(PT)衍生物、聚对苯撑乙烯(PPV)衍生物等有机光伏材料在聚合物太阳能电池中的应用进行综述,简单探讨了该领域进一步研究的方向和前景。     

具备良好导电性和稳定性的新型PPV聚合物

<正>聚对苯撑乙炔(PPV)聚合物具有导电和光学特性,在太阳能、传感器技术、发光二极管等领域得到广泛应用。经过4年的研究和实验,Gl?cklhofer团队发现了一种可靠、直接的方法来生产PPV,包括使用微波辐射来生产合适的聚合单体,然后进一步修改编组。"反应在     

高耐热性硅基聚合物

高耐热性硅基聚合物日本三井东压化学公司已合成耐热性比碳基聚合物中的仅仅者聚酰亚胺还优越的硅基聚合物。这种新聚合物为聚［（苯基甲硅撑）乙炔间苯撑乙炔），耐热性相当高，可用作宇宙飞船的中间壁、高层大楼的阻燃材料以及苛刻环境中使用的其他难燃材料。这种硅基聚...     

具有规整PPV侧链无机高分子聚磷腈的合成与表征

利用反应性无机高分子聚 (二氯 )磷腈与功能性寡聚聚对苯乙炔的亲核取代反应 ,合成了具有规整寡聚聚对苯乙炔 (OPPV)侧链的高分子聚磷腈 (PPZ)。采用NMR(3 1P ,1H ,13 C) ,FT TR、GPC、DSC、TGA等对所得无机聚合物进行了结构表征和性能测试。以所合成的聚合物作发光材料 ,制备了聚合物发光器件 ,并对器件性能进行了初步研究。实验结果表明 :聚合物具有优异的溶解性能和成膜性能 ,通过旋涂法可获得符合要求的发光薄膜。聚合物玻璃化转变温度 (Tg)为 97℃ ,开始热分解温度为 387℃。聚合物LED的发光波长为 4 12nm ,为蓝色电致发光。     

Branched poly(p‐phenylenevinylene): Synthesis,optical and electrochemical properties

A series of poly(p‐phenylene vinylene) (PPV) derivatives with phenylene vinylene side chains (branched PPVs), PPV0, PPV1, PPV2, and PPV3, were synthesized by the Heck coupling reaction and characterized by TGA, absorption spectra, photoluminescence (PL) spectra, and electrochemical cyclic voltammetry. The branched PPVs showed two absorption peaks in the UV–vis region, corresponding to the conjugated side chains (UV absorption) and the main chains (the visible absorption). Especially the absorption spectrum of PPV3 covers a broad wavelength range from 300 to 500 nm. Introducing the electron‐donating alkoxy substituents on the PPV main chains and increasing the content of the alkoxy groups lead to bathochromic shift of both absorption and PL spectra from PPV1 to PPV2 to PPV3. The onset oxidation potential of the branched PPVs is lower by 0.1–0.2 V than that of PPV, indicating that the electron‐donating ability of the branched PPVs enhanced in comparison with that of PPV. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Effects of a tert‐butylphenylene substituent on the structure and optical,fluorescent and thermal properties of the poly(p‐phenylenevinylene) derivatives

Two soluble fluorescent polymers, poly(2‐decyloxy‐5‐(4′‐tert‐butylphenyl)‐1,4‐phenylenevinylene) (DtBP‐PPV) and poly(2‐decyloxy‐1,4‐phenylenevinylene) (DO‐PPV), were prepared by a method similar to the Gilch procedure. The DtBP‐PPV and DO‐PPV have a same chemical structure except for the conjugated tert‐bytulphenyl substituents in the former. The polymers are characterized by using ¹H NMR, FTIR, UV–vis, photoluminescence (PL), and electroluminescence (EL) spectroscopies and thermogravimetric analysis (TGA). The ¹H NMR spectra show no tolane‐bis‐benzyl (TBB) structure defects in DtBP‐PPV but some in DO‐PPV. Both UV–vis absorption and PL emission peaks of the DtBP‐PPV exhibit a red‐shift phenomenon as compared with those of the DO‐PPV. Moreover, with the DtBP‐PPV and DO‐PPV acting as light‐emitting polymers separately, EL devices were fabricated with a sequential lamination of ITO/PEDOT/DtBP‐PPV (or DO‐PPV)/Ca/Ag. The DtBP‐PPV‐based device shows a lower turn‐on voltage, a longer EL emission wavelength, and a higher brightness than the DO‐PPV‐based device. The maximum brightness of DtBP‐PPV‐based device is 57 cd/m² at an applied voltage of 12 V. POLYM. ENG. SCI., 47:1380–1387, 2007. © 2007 Society of Plastics Engineers     

Structural characterization and luminescent properties of poly(p-phenylene vinylene) and poly(ethylene glycol) blends

The luminescent properties of poly(p-phenylenevinylene) (PPV) blending with poly (ethylene glycol) (PEG) were investigated in terms of their structural formation during sample preparation. The blended systems were prepared from an aqueous solution of water-soluble poly (xylylene tetrahydrothiophenium chloride) (PPV precursor) mixed with PEG, followed by heat treatment to remove the tetrahydrothiophene groups from the PPV precursor. Structural analysis showed that PEG could react with PPV precursor to form C-O-C linkage and carbonyl groups in PPV chains, interrupting their conjugated length as suggested by their Infrared, Raman and UV/vis spectroscopes. Wide angle X-ray scattering (WARS) of blended systems also showed that PPV in blends had less packing. As to luminescent properties, the UV/vis and photoluminescent (PL) spectra show that the energy gap needed to produce the excitons increased along with the increase of PL intensity when PPV was blended with PEG. Similar results were also found for the EL properties of ITO/polyblends/Al devices. The EL light emission from blends was blue-shifted (compared to PPV) with a rather low threshold electric field strength. The EL performance of polyblends was better than that of pure PPV. Among them, the PPV-50PEG showed the highest EL intensity. The improved EL efficiency was attributed to the dilution effect, interrupted conjugated length, and lower packing of PPV chains.     

Electrical and electroluminescent properties of poly(p-phenylene vinylene) LB films based LEDs using aluminum metal as the electrode

The electrical properties of poly(p-phenylene vinylene) (PPV) Langmuir-Blodgett (LB) films were investigated, wherein transparent indium-tin oxide (ITO) and aluminum (Al) were used as the electrodes. Their I–V characteristics depended strongly on the thickness of PPV LB film, and the electric conductivity of the PPV LB film was in the range of 10⁻²–10⁻¹⁵ (S/cm). Their C–V characteristics showed that the capacitance was reversibly proportional to the thickness of PPV LB film and was kept constant when the applied voltage changed from −1.0 V to +1.0 V. These results indicated that PPV LB film was an insulator in this range of applied voltage without doping. Under forward bias, yellow-green light emission was observed in PPV LB film based light emitting diodes (LEDs), the highest light emission reached more than 100 cd/m² in the case that PPV LB film was deposited for 80 layers, i.e. a ITO/PPV(80L)/Al device.     

Synthesis and light‐emitting properties of new poly(p‐phenylenevinylene) derivatives containing oxadiazole moiety

Two new poly(p‐phenylenevinylene) (PPV) derivatives containing oxadiazole moiety (OXA‐PPV1 and OXA‐PPV2) were synthesized by the Wittig condensation polymerization reaction. Their thermal and light‐emitting properties were investigated. The single‐ and triple‐layer electroluminescent (EL) devices with configurations of ITO/polymer/Al and ITO/polymer/OXD‐7/Alq₃/Al were fabricated. They exhibited blue emission at 470 nm for OXA‐PPV1 and green emission at 560 nm for OXA‐PPV2. The turn‐on voltages of triple‐layer device were 11 V for OXA‐PPV1 and 8 V for OXA‐PPV2. The triple‐layer EL devices showed much better performance than did the single‐layer devices. The spectra indicated energy transfer occurred from segments of side chain to polymer backbone. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 422–428, 2002     

Emission properties of composite semiconducting polymer nanoparticles

A series of composite polymer nanoparticles was prepared from poly(N‐vinylcarbazole) (PVK) and poly(2,5‐bistriethoxy‐p‐phenylene vinylene‐alt‐phenylene vinylene) (BTEO–PPV‐alt‐PPV). The nanoparticle sizes were measured to be in the range of 50–80 nm with transmission electron microscopy. The photoluminescence intensity of PVK decreased with the content of BTEO–PPV‐alt‐PPV increasing in the composite polymer nanoparticles because the excited states in PVK were quenched by BTEO–PPV‐alt‐PPV. The emission from BTEO–PPV‐alt‐PPV was enhanced in the composite polymer nanoparticles because of energy transfer from PVK to BTEO–PPV‐alt‐PPV for excitation at the absorption maximum of PVK. The energy‐transfer efficiency was markedly improved in the composite polymer nanoparticles versus the composite polymer films according to emission spectral analyses. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Synthesis and light‐emitting properties of new poly(p‐phenylenevinylene) derivatives containing oxadiazole moiety

Two new poly(p‐phenylenevinylene) (PPV) derivatives containing the oxadiazole moiety (OXA–PPV1 and OXA–PPV2) were synthesized by the Wittig condensation polymerization reaction and their thermal and light‐emitting properties were investigated. The single‐layer and triple‐layer electroluminescent (EL) devices with configurations of ITO/OXA–PPV1/Al and ITO/OXA–PPV1/OXD/Alq₃/Al were fabricated. They both exhibited blue emission at 460 nm. For comparison, the PPV derivative containing the oxadiazole moiety only in the side chains (OXA–PPV2) was also synthesized. Both single‐layer and triple‐layer EL devices with OXA–PPV2 as the emissive layer emitted green‐light at 560 nm. The turn‐on voltages of the triple‐layer device was 11 V for OXA–PPV1 and 8 V for OXA–PPV2. The triple‐layer EL devices showed much better performance than that of the single‐layer devices. The spectra indicated that energy or electron transfer occurred from the side‐chain oxadiazole to the main‐chain styrene unit. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2424–2428, 2002     

Enhancement of the electrical properties of poly(p‐phenylene vinylene) by the incorporation of silicon dioxide nanoparticles

The electrical properties of a poly(p‐phenylene vinylene) (PPV) conjugated polymer using silver (Ag) as a cathode were improved by the incorporation of silicon dioxide (SiO₂) nanoparticles. The current density of the Ag–PPV/SiO₂ nanocomposite system was higher than that of Ag–PPV. A lower level of interfacial oxidation was found in the Ag–PPV/SiO₂ nanocomposite than in Ag–PPV, confirming that a more complete elimination of residue occurred in the nanocomposite. This was due to the relatively large surface area of the PPV/SiO₂ nanocomposite film and the hydrophilic surface of the SiO₂ nanoparticles. The lower level of oxidation contributed to an improvement in the material's current–voltage characteristics. Morphology‐dependent current–voltage characteristics were enhanced by a large variation in the thickness of the Ag–PPV/SiO₂ nanocomposite film because an increased effective field strength could be induced in the thinner regions of the film. The incorporation of SiO₂ nanoparticles altered the effective film thickness and the amount of residue in the interior of the PPV without disrupting the structure of the conjugated polymer. The Ag cathode created a stable interface with the PPV film layer without causing the formation of an organic–metal complex, which would have obstructed electron injection. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Characterization of anisotropic structure in poly(phenylene vinylene) films

The evolution of the anisotropic structure in poly(phenylene vinylene) (PPV) films was studied using three nondestructive characterization techniques: prism waveguide coupling, infrared dichroism, and X‐ray diffraction. The anisotropic PPV films were thermally converted from precursor drawn films at fixed length. The three‐dimensional refractive indices, infrared dichroic ratios, crystal alignment, and orientation function were determined from each film. The results show that converted cast PPV film has a highly planar structure with a tendency for the PPV chains to orient parallel to the film surface. The a axis of the crystal unit cell is normal to the film plane. One‐way stretching converts the film from a planar structure to a uniaxial structure.     

Synthesis,photo‐, and electroluminescent properties of the soluble poly[(2,5‐diphenylene‐1,3,4‐oxadiazole)‐ 4,4′‐vinylene]

A novel soluble conjugated polymer, poly[(2,5‐diphenylene‐1,3,4‐oxadiazole)‐4,4′‐vinylene] (O‐PPV), containing an electron‐transporting group on the main chain of PPV, was synthesized according to HORNER mechanism. The oligo‐polymer with M_w = 1000 and T_d = 270°C is soluble in chloroform and tetrahydrofuran. The photoluminescent (PL) properties were investigated using different concentrations of solid‐state O‐PPV/PEO blends absorption and selective excitation measurements. The results show that PL arises from interchain charge‐transfer states in solid‐state O‐PPV. Compared with the analogous single‐layer device constructed with PPV (ITO/PPV/Al), which emits two peaks at λ = 520 nm and 550 nm (shoulder), the electroluminescence (EL) spectrum of the device [ITO/O‐PPV (80 nm)/Al] is a broad peak at λ_max = 509 nm. The quantum efficiency (0.13%) of the device ITO/O‐PPV/Al is much higher than that of the device ITO/PPV/Al, due to the introduction of the electron‐transporting group–oxadiazole units in the main chain of PPV. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 3535–3540, 1999