Synthesis and properties of phenothiazylene vinylene‐based polymers: New organic semiconductors for field‐effect transistors and solar cells

A series of new phenothiazylene vinylene‐based semiconducting polymers, poly[3,7‐(4′‐dodecyloxyphenyl)phenothiazylene vinylene] ( P1 ), poly[3,7‐(4′‐dodecyloxyphenyl)phenothiazylene vinylene‐alt‐1,4‐phenylene vinylene] ( P2 ), and poly[3,7‐(4′‐dodecyloxyphenyl)phenothiazylene vinylene‐alt‐2,5‐thienylene vinylene] ( P3 ), have been synthesized via a Horner‐Emmons reaction. FTIR and ¹H NMR spectroscopies confirmed that the configurations of the vinylene groups in the polymers were all‐trans (E). The weight‐averaged molecular weights (M_w) of P1 , P2 , and P3 were found to be 27,000, 22,000, and 29,000, with polydispersity indices of 1.91, 2.05, and 2.25, respectively. The thermograms for P1 , P2 , and P3 each contained only a broad glass transition, at 129, 167, and 155 °C, respectively, without the observation of melting features. UV–visible absorption spectra of the polymers showed two strong absorption bands in the ranges 315–370 nm and 450–500 nm, which arose from absorptions of the phenothiazine segments and the conjugated main chains. Solution‐processed field‐effect transistors fabricated from these polymers showed p‐type organic thin‐film transistor characteristics. The field‐effect mobilities of P1 , P2 , and P3 were measured to be 1.0 × 10^?4, 3.6 × 10^?5, and 1.0 × 10^?3 cm² V^?1 s^?1, respectively, and the on/off ratios were in the order of 10² for P1 and P2 , and 10³ for P3 . Atomic force microscopy and X‐ray diffraction analysis of thin films of the polymers show that they have amorphous structures. A photovoltaic device in which a P3 /PC₇₁BM (1/5) blend film was used as the active layer exhibited an open‐circuit voltage (V_OC) of 0.42 V, a short circuit current (J_SC) of 5.17 mA cm^?2, a fill factor of 0.35, and a power conversion efficiency of 0.76% under AM 1.5 G (100 mW cm^?2) illumination. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 635–646, 2010     

Solid‐state NMR as a tool to describe and quantify the morphology of photoactive layers used in plastic solar cells

The optimization and control of the nanomorphology of thin films used as active layer in bulk heterojunction (BHJ) plastic solar cells is of key importance for a better understanding of the photovoltaic mechanisms and for increasing the device performances. Hereto, solid‐state NMR relaxation experiments have been evaluated to describe the film morphology of one of the “work‐horse” systems poly(2‐methoxy‐5‐(3′,7′‐dimethyloctyloxy)‐1,4‐phenylene‐vinylene)/[6, 6]‐phenyl‐C₆₁butyric acid methyl ester (MDMO‐PPV/PCBM) in a quantitative way. Attention is focused on the influence of the processing solvent (toluene vs. chlorobenzene), the blend composition, and the casting technique, that is, spin coating versus doctor blading. It is demonstrated that independently of the solvent and casting technique, part of the PCBM becomes phase separated from the mixed phase. Whereas casting from toluene results in the development of well‐defined PCBM crystallites, casting from chlorobenzene leads to the formation of PCBM‐rich domains that contain substructures of weakly organized PCBM nanoclusters. The amount and physico‐chemical state of the phase separated PCBM is quantified by solid‐state NMR relaxation times experiments. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

哒嗪并吡咯二酮共轭聚合物半导体材料的合成及晶体管性能

采用Stille交叉偶联反应,合成了基于6-烷基吡咯[3,4-d]哒嗪-5,7-二酮(PPD)与吡咯并吡咯二酮(DPP)结构单元的受体-π-受体(A_1-π-A_2)型共轭聚合物(PPPD-DPP)。采用热重分析仪、紫外分光光度计、电化学工作站等表征了聚合物PPPD-DPP的性能,系统地研究了聚合物的热性能、光物理性能、电化学性能及晶体管性能。结果表明:聚合物PPPD-DPP具有良好的热稳定性,热分解温度达到376℃;薄膜的最大吸收峰位于702nm,光学能带隙为1.27eV;有较低的最高占据分子轨道能级(HOMO,-5.23eV)。基于PPPD-DPP的有机薄膜晶体管(OTFTs)器件在真空中显示出双极性传输特性,最高电子和空穴迁移率分别为0.030 cm~2/(V·s)和0.054cm~2/(V·s),在空气中PPPD-DPP器件则表现出明显的p型传输特性,空穴迁移率提升至0.121cm~2/(V·s)。     

Thermally curable organic/inorganic hybrid polymers as gate dielectrics for organic thin‐film transistors

New low‐temperature curable organic/inorganic hybrid polymers were designed and synthesized as gate dielectrics for organic thin‐film transistors (OTFTs). Allyl alcohols were introduced to polyhedral oligomeric silsesquioxane (POSS) via hydrosilyation to produce an alcohol‐functionalized POSS derivative (POSS‐OH). POSS‐OH was then reacted with hexamethoxymethylmelamine at carrying molar ratios at 80 °C in the presence of a catalytic amount of p‐toluenesulfonic acid to give highly cross‐linked network polymers (POSS‐MM). The prepared thin films were smooth and hard after the thermal cross‐linking reaction and had very low leakage currents (<10^?8 A/cm²) with no significant absorption over the visible spectral range. Pentacene‐based OTFTs using the synthesized insulators as gate dielectric layers had higher hole mobilities (up to 0.36 cm²/Vs) than a device using thermally cross‐linked poly(vinyl phenol) and melamine as the gate dielectric layer (0.18 cm²/Vs). © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 3260–3268     

Field‐effect transistors based on PPV derivatives as a semiconducting layer

A series of modified thiophene groups containing PPV‐based semiconducting materials, poly[(2,5‐bis(octyloxy)‐1,4‐phenylenevinylene)‐alt‐(2,2′bithienylenevinylene)] ( PPBT ), poly[(2,5‐bis(octyloxy)‐1,4‐phenylenevinylene)‐alt‐(5,5‐thiostilylenevinylene)] ( PPTVT ), have been synthesized through a Horner coupling reaction. From the FTIR and ¹H NMR spectroscopy, the configuration of the vinylene groups in the polymers was all trans (E) geometry. The weight‐average molecular weights (M_w) of PPBT and PPTVT were found to be 11,700 and 11,800, with polydispersity indices of 2.51 and 2.53, respectively. PPBT and PPTVT thin films exhibit UV–visible absorption maxima at 538 and 558 nm, respectively, and the strong absorption shoulder peaks at 578 and 602 nm, respectively. Solution processed field‐effect transistors (FET) fabricated using all the polymers showed p‐type OTFT characteristics. The field‐effect mobility of the PPTVT was obtained up to 2.3 × 10^?3 cm² V^?1 s^?1, an on/off ratio of 1.0 × 10⁵ with ambient air stability. Studies of the atomic force microscopy (AFM) and X‐ray diffraction (XRD) analysis of the polymer thin films revealed that all the polymers were amorphous structure. The greater planarity and rigidity of PPTVT compared to PPBT results in elongation of conjugation length and better π–π stacking of polymer chains in amorphous region, which leads to improved FET performance. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 111–120, 2009     

Development of a new conjugated polymer containing dialkoxynaphthalene for efficient polymer solar cells and organic thin film transistors

A new semiconducting polymer, poly((5,5‐E‐α‐((2‐thienyl)methylene)‐2‐thiopheneacetonitrile)‐alt‐2,6‐[(1,5‐didecyloxy)naphthalene])) (PBTADN), an alternating copolymer of 2,3‐bis‐(thiophene‐2‐yl)‐acrylronitrile and didecyloxy naphthalene, is synthesized and used as an active material for organic thin film transistors (OTFTs) and organic solar cells. The incorporation of 2,3‐bis‐(thiophene‐2‐yl)‐acrylronitrile as an electron deficient group and didecyloxy naphthalene as an electron rich group resulted in a relatively low bandgap, high charge carrier mobility, and finally good photovoltaic performances of PBTADN solar cells. Because of the excellent miscibility of PBTADN and PC₇₁BM, as confirmed by Grazing Incident X‐ray Scattering (GIXS) measurements and Transmission Electron Microscopy (TEM), homogeneous film morphology was achieved. The maximum power conversion efficiency of the PBTADN:PC₇₁BM solar cell reached 2.9% with a V_oc of 0.88 V, a short circuit current density (J_sc) of 5.6 mA/cm², and a fill factor of 59.1%. The solution processed thin film transistor with PBTADN revealed a highest saturation mobility of 0.025 cm²/Vs with an on/off ratio of 10⁴. The molecular weight dependence of the morphology, charge carrier mobility, and finally the photovoltaic performances were also studied and it was found that high molecular weight PBTADN has better self assembly characteristics, showing enhanced performance. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Highly thermostable and low birefringent norbornene‐styrene copolymers with advanced optical properties: A potential plastic substrate for flexible displays

This article reports the synthesis and characterization of an extremely high thermostable cyclic olefin copolymer with advanced optical properties resulting from the vinyl addition copolymerization of norbornene with styrene catalyzed by a substituted fluorenylamidodimethyltitanium catalyst [Me₂Si(3,6‐tBu₂Flu)(tBuN)]TiMe₂ activated with a [Ph₃C] [B(C₆F₅)₄]/Al(iBu)₃ cocatalyst using o‐dichlorobenzene as solvent. The prepared copolymer possesses a glass transition temperature as high as polyimide (T_g > 300 °C) and a high transmittance which is comparable with that of the conventional optical resins ([T] > 90%). The incorporation of polystyrene, which exhibits a negative birefringence into the vinyl‐added polynorbornene that possesses an intrinsic positive birefringence, effectively reduced the birefringent magnitude of the norbornene‐styrene copolymer due to a mutual compensation between these opposite‐sign birefringences. The absence of any functional and aromatic heterocyclic groups and the presence of highly hydrophobic saturated bicyclic rings in the copolymer main chains effectively prevented the diffusion of water/oxygen and thus enhanced the dimensional and optical stabilities of the material. Preliminary results on the characterization of the thermal stability, mechanical, and optical properties of the vinyl‐added norbornene‐styrene copolymers indicate that they satisfy all the rigorous requirements for a polymer to be applied as a flexible substrate for the manufacturing of the flexible displays. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010     

Donor–acceptor alternating π‐conjugated polymers containing Di(thiophen‐2‐yl)pyrene and 2,5‐Bis(2‐octyldodecyl)pyrrolo[3,4‐c]pyrrole‐1,4(2H,5H)‐dione for organic thin‐film transistors

New diketopyrrolopyrrole (DPP)‐containing conjugated polymers such as poly(2,5‐bis(2‐octyldodecyl)‐3‐(5‐(pyren‐1‐yl)thiophen‐2‐yl)‐6‐(thiophen‐2‐yl)pyrrolo[3,4‐c]pyrrole‐1,4(2H,5H)‐dione) (P(DTDPP‐alt‐(1,6)PY)) and poly(2,5‐bis(2‐octyldodecyl)‐3‐(5‐(pyren‐2‐yl)thiophen‐2‐yl)‐6‐(thiophen‐2‐yl)pyrrolo[3,4‐c]pyrrole‐1,4(2H,5H)‐dione) (P(DTDPP‐alt‐(2,7)PY)) were successfully synthesized via Suzuki coupling reactions under Pd(0)‐catalyzed conditions. P(DTDPP‐alt‐(2,7)PY), incorporating 2,5‐bis(2‐octyldodecyl)‐3,6‐di(thiophen‐2‐yl)pyrrolo[3,4‐c]pyrrole‐1,4(2H,5H)‐dione (DTDPP) at the 2,7‐position of a pyrene ring showed a lower band‐gap energy (E. = 1.65 eV) than the 1,6‐substituted analog, P(DTDPP‐alt‐(1,6)PY) (E = 1.71 eV). The energies of the molecular frontier orbitals of the substituted polymers were successfully tuned by changing the anchoring position of DTDPP from the 1,6‐ to the 2,7‐position of the pyrene ring. An organic thin‐film transistor fabricated using the newly synthesized P(DTDPP‐alt‐(2,7)PY), as a semiconductor material exhibited a maximum mobility of up to 0.23 cm² V^?1 s^?1 (I_on/off ～ 10⁶), which was much larger than that obtained using P(DTDPP‐alt‐(1,6)PY). This distinction is attributed to morphological differences in the solid state arising from differences between the geometrical configurations of DTDPP and the pyrene ring. In addition, the organic phototransistor devices made of P(DTDPP‐alt‐(2,7)PY) showed interesting photoinduced enhancement of drain current when irradiating the excitation light whose intensity is very small. Based on the photoinduced effect on I_DS, photocontrolled memory could be realized under the variation of gate voltages. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013     

Naphthodithiophene‐Diketopyrrolopyrrole‐Based donor–Acceptor alternating π‐Conjugated polymers for Organic thin‐Film transistors

Novel naphtho[1,2‐b:5,6‐b′]dithiophene (NDT) and diketopyrrolopyrrole (DPP)‐containing donor‐acceptor conjugated polymers (PNDTDPPs) with different branched side chains were synthesized via Pd(0)‐catalyzed Stille coupling reaction. Octyldodecyl (OD) and dodecylhexadecyl (DH) groups were tethered to the DPP units as the side chains. The soluble fraction of PNDTDPP‐OD polymer in chloroform has much lower molecular weight than that of PNDTDPP‐DH polymer. PNDTDPP‐DH polymer bearing relatively longer DH side chains exhibited much better charge‐transport behavior than PNDTDPP‐OD polymer with shorter OD side chains. The thermally annealed PNDTDPP‐DH polymer thin films exhibited an outstanding charge carrier mobility of ～1.32 cm² V^?1 s^?1 (I_on/I_off ～ 10⁸) measured under ambient conditions, which is almost six times higher than that of thermally annealed PNDTDPP‐OD polymer thin films. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51, 5280–5290     

Applications of Oligomers for Nanostructured Conducting Polymers

This Feature Article provides an overview of the distinctive nanostructures that aniline oligomers form and the applications of these oligomers for shaping the nanoscale morphologies and chirality of conducting polymers. We focus on the synthetic methods for achieving such goals and highlight the underlying mechanisms. The clear advantages of each method and their possible drawbacks are discussed. Assembly and applications of these novel organic (semi)conducting nanomaterials are also outlined. We conclude this article with our perspective on the main challenges, new opportunities, and future directions for this nascent yet vibrant field of research.

     

Regular conjugated terpolymers comprising two different acceptors and bithiophene donor in repeating group: Effect of strong and weak acceptors on semiconducting properties

Diketopyrrolopyrrole (DPP)‐based terpolymers—P(DPP‐TPyT) and P(DPP‐T3MTT)—bearing bithiophene donating groups and weak accepting units such as pyridine (Py) or methyl thiophene‐3‐carboxylate (3MT), in the polymer backbone, were successfully synthesized. Although the two polymers had similar physical and electrochemical properties, grazing incidence X‐ray diffraction patterns of P(DPP‐TPyT) and P(DPP‐T3MTT) showed mixed and edge‐on orientations, respectively, in thermally annealed films. Accordingly, the P(DPP‐T3MTT) showed twice the hole mobility of P(DPP‐TPyT) in a thin‐film transistor, and a blended film of P(DPP‐T3MTT) and [6,6]‐phenyl‐C71‐butyric acid methyl ester (PC₇₁BM) showed better power conversion efficiency in a polymer solar cell. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 1339‐1347     

Liquid crystalline conjugated polymers and their applications in organic electronics

This article describes the syntheses and electro‐optical applications of liquid crystalline (LC) conjugated polymers, for example, poly(p‐phenylenevinylene), polyfluorene, polythiophene, and other conjugated polymers. The polymerization involves several mechanisms: the Gilch route, Heck coupling, or Knoevenagel condensation for poly(p‐phenylenevinylene)s, the Suzuki‐ or Yamamoto‐coupling reaction for polyfluorenes, and miscellaneous coupling reactions for other conjugated polymers. These LC conjugated polymers are classified into two types: conjugated main chain polymers with long alkyl side chains, namely main‐chain type LC polymers, and conjugated polymers grafting with mesogenic side groups, namely side‐chain type LC conjugated polymers. In general, the former shows higher transition temperature and only nematic phase; the latter possesses lower transition temperature and more mesophases, for example, smectic and nematic phases, depending on the structure of mesogenic side chains. The fully conjugated main chain promises them as good candidates for polarized electroluminescent or field‐effect devices. The polarized emission can be obtained by surface rubbing or thermal annealing in liquid crystalline phase, with maximum dichroic ratio more than 20. In addition, conjugated oligomers with LC properties are also included and discussed in this article. Several oligo‐fluorene derivatives show outstanding polarized emission properties and potential use in LCD backlight application. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2713–2733, 2009     

Synthesis and characterization of thiazolothiazole‐based polymers and their applications in polymer solar cells

A novel series of thiazolothiazole (Tz)‐based copolymers, poly[9,9‐didecylfluorene‐2,7‐diyl‐alt‐2,5‐bis‐(3‐hexylthiophene‐2‐yl)thiazolo[5,4‐d]thiazole] (P1), poly[9,9‐dioctyldibenzosilole‐2,7‐diyl‐alt‐2,5‐bis‐(3‐hexylthiophene‐2‐yl)thiazolo[5,4‐d]thiazole] (P2), and poly[4,4′‐bis(2‐ethylhexyl)‐dithieno[3,2‐b:2′,3′‐d]silole‐alt‐2,5‐bis‐(3‐hexylthiophene‐2‐yl)thiazolo[5,4‐d]thiazole] (P3), were synthesized for the use as donor materials in polymer solar cells (PSCs). The field‐effect carrier mobilities and the optical, electrochemical, and photovoltaic properties of the copolymers were investigated. The results suggest that the donor units in the copolymers significantly influenced the band gap, electronic energy levels, carrier mobilities, and photovoltaic properties of the copolymers. The band gaps of the copolymers were in the range of 1.80–2.14 eV. Under optimized conditions, the Tz‐based polymers showed power conversion efficiencies (PCEs) for the PSCs in the range of 2.23–2.75% under AM 1.5 illumination (100 mW/cm²). Among the three copolymers, P1, which contained a fluorene donor unit, showed a PCE of 2.75% with a short‐circuit current of 8.12 mA/cm², open circuit voltage of 0.86 V, and a fill factor (FF) of 0.39, under AM 1.5 illumination (100 mW/cm²). © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

High performance semiconducting polymers containing bis(bithiophenyl dithienothiophene)‐based repeating groups for organic thin film transistors

New dithienothiophene‐containing conjugated polymers, such as poly(2,6‐bis(2‐thiophenyl‐3‐dodecylthiophene‐2‐yl)dithieno[3,2‐b;2′,3′‐d]thiophene, 4 and poly(2,6‐bis (2‐thiophenyl‐4‐dodecylthiophene‐2‐yl)dithieno[3,2‐b;2′,3′‐d]thiophene, 8 have been successfully synthesized via Stille coupling reactions using dodecyl‐substituted thiophene‐based monomers, bistributyltin dithienothiophene, and bistributyltin bithiophene; these polymers have been fully characterized. The main difference between the two polymers is the substitution position of the dodecyl side chains in the repeating group. Grazing‐incidence X‐ray diffraction (GI‐XRD) gave clear evidence of edge‐on orientation of polycrystallites to the substrate. The semiconducting properties of the two polymers have been evaluated in organic thin film transistors (OTFTs). The two conjugated polymers 4 and 8 exhibit fairly high hole carrier mobilities as high as μ_ave = 0.05 cm²/Vs (I_ON/OFF = 3.42 × 10⁴) and μ_ave = 0.01 cm²/Vs, (I_ON/OFF = 1.3 × 10⁵), respectively, after thermal annealing process. The solvent annealed films underwent reorganization of the molecules to induce higher crystallinity. Well‐defined atomic force microscopy (AFM) topography supported a significant improvement in TFT device performance. The hole carrier mobilities of the solvent annealed films are comparable to those obtained for a thermally annealed sample, and were one‐order higher than those obtained with a pristine sample. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010     

全印刷碳纳米管薄膜晶体管构建及电性能研究

利用纳米压印和电刷镀技术在PET基体上制作出大面积金源、漏电极阵列。分别采用钛酸钡复合材料为介电层,印刷银电极为顶电极,聚芴-二噻吩基吡咯并吡咯二酮(PF8DPP)分离的半导体碳纳米管为有源层,在柔性基体上构建出全印刷碳纳米管薄膜晶体管器件和反相器。全印刷碳纳米管薄膜晶体管的开关比和迁移率分别达到4×10⁴和6 cm²·V^-1·s^-1,且器件表现出零回滞特性。构建的反相器在V_dd =8 V时,其增益可以达到12。     

Covalently Scaffolded Inter‐π‐System Orientations in π‐Conjugated Polymers and Small Molecule Models

Organic π‐conjugated polymers have emerged as one of the most fascinating classes of materials as they have found utility in a host of plastic electronics technologies. The distance between π‐systems and their relative orientation dictate energy/charge transfer, conductivity, and photophysical properties of these materials in bulk. This Feature Article discusses π‐conjugated polymers and model compounds in which specific inter‐π‐system interactions are covalently enforced and the effect that the scaffolding has on optoelectronic properties.

     

n‐Channel Organic Transistors Processed from Halogen‐Free Solvents: Solvent Effect on Thin‐Film Morphology and Charge Transport

Non‐chlorinated solvents are highly preferable for organic electronic processing due to their environmentally friendly characteristics. Four different halogen‐free solvents, tetrafuran, toluene, meta‐xylene and 1,2,4‐trimethylbenzene, were selected to fabricate n‐channel organic thin film transistors (OTFTs) based on 3‐hexylundecyl substituted naphthalene diimides fused with (1,3‐dithiol‐2‐ylidene)malononitrile groups (NDI3HU‐DTYM2). The OTFTs based on NDI3HU‐DTYM2 showed electron mobility of up to 1.37 cm²·V^?1·s^?1 under ambient condition. This is among the highest device performance for n‐channel OTFTs processed from halogen‐free solvents. The different thin‐film morphologies, from featureless low crystalline morphology to well‐aligned nanofibres, have a great effect on the device performance. These results might shed some light on solvent selection and the resulting solution process for organic electronic devices.     

Two dibenzo[Def,Mno]chrysene‐based polymeric semiconductors: Surprisingly opposite device performances in field‐effect transistors and solar cells

A new series of conjugated polymers containing dibenzo[def, mno]chrysene units were successfully designed and synthesized to investigate their physical properties and device performances in field‐effect transistors and photovoltaic cells. Two polymers, namely poly(4,10‐bithiophene‐6,12‐bis(2‐decyltetradecyloxy)‐dibezo[def, mno]chrysene) ( PTTC) and poly(2,2′‐thiophenevinylenthiophene‐4,10‐[6,12‐bis(2‐decyltetradecyloxy)‐dibenzo[def, mno]chrysene]) ( PTVTC) , exhibited similar light absorption, electrochemical characteristics, and theoretical electronic structures. However, they behaved very differently when used in thin‐film transistors and solar cells. The PTTC polymer with two thiophene groups had better charge transport behavior, whereas the PTVTC polymer with two thiophene units connected by a vinyl group exhibited higher efficiency in bulk heterojunction photovoltaic cells. These results were discussed in terms of their nanostructural bulk morphologies established from transmission electron microscopy and two‐dimensional grazing incidence wide angle X‐ray scattering analyses. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 2559–2570     

Oxidation potential of thiophene oligomers: Theoretical and experimental approach

Intrinsic properties of conducting polymers, such as oxidation potential and band gap, are very important for designing new materials with improved properties. Computational chemistry offers suitable tools capable of predicting these quantities. This work presents electrochemical information about accurate oxidation potentials of oligothiophenes and polymer band gap. These are compared to theoretical predictions based on electronic structure calculations at Density Functional Theory levels, coupled with self‐consistent reaction field. All computational protocols gave a qualitative prediction of the experimental trend. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011     

金属氧化物TFT驱动AMOLED显示研究进展

金属氧化物薄膜晶体管（metal oxide thin film transistor,MOTFT）由于具有迁移率高、均匀性好、工艺简单、工艺温度低、成本低等优势,非常适合高分辨率、大尺寸液晶显示（LCD）和有源矩阵有机发光二极管显示（AMOLED）等新型显示技术发展的需要,因此受到业界和学界的广泛关注．结合本课题组的工作,本文阐述了MOTFT的材料、器件结构、制作工艺以及应用,并对影响MOTFT性能的因素进行了讨论．本课题组开发的新型MOTFT迁移率可达35cm^2／（Vs）,阈值电压为1．63V,开关比为10^9,亚阈值摆幅为0．21Wdecade．基于自主开发的MOTFT背板,在国内率先实现了3—5英寸彩色AMOLED显示屏、透明AMOLED显示屏以及柔性AMOLED显示屏,展示了MOTFT背板良好的应用前景．