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1.
New all‐conjugated block copolythiophene, poly(3‐hexylthiophene)‐block‐poly(3‐(4′‐(3″,7″‐dimethyloctyloxy)‐3′‐pyridinyl)thiophene) (P3HT‐b‐P3PyT) was successfully prepared by Grignard metathesis polymerization. The supramolecular interaction between [6,6]‐phenyl‐C61‐butyric acid methyl ester (PCBM) and P3PyT was proposed to control the aggregated size of PCBM and long‐term thermal stability of the photovoltaic cell, as evidenced by differential scanning calorimetry (DSC), transmission electron microscopy (TEM), and optical microscopy. The effect of different solvents on the electronic and optoelectronic properties was studied, including chloroform (CL), dichlorobenzene (DCB), and mixed solvent of CL/DCB. The optimized bulk heterojunction solar cell devices using the P3HT‐b‐P3PyT/PCBM blend showed a power conversion efficiency of 2.12%, comparable to that of P3HT/PCBM device despite the fact that former had a lower crystallinity or absorption coefficient. Furthermore, P3HT‐b‐P3PyT could be also used as a surfactant to enhance the long‐term thermal stability of P3HT/PCBM‐based solar cells by limiting the aggregated size of PCBM. This study represents a new supramolecular approach to design all‐conjugated block copolymers for high‐performance photovoltaic devices. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011.  相似文献   

2.
A new polymeric dyad of oligo‐anthracene‐block‐poly(3‐hexylthiophene) (Oligo‐ANT‐b‐P3HT) has been synthesized as a donor–donor dyad building block for organic photovoltaics. The polymer dyad and oligomer of anthracene‐9,10‐diyl (Oligo‐ANT) are prepared by Grignard Metathesis. The higher order of crystallinity and molecular chains ordering at solid phase reveal the intrinsic optical and electrical properties of polymeric dyad resulting in relatively higher light harvesting ability compared to the oligo(anthracene‐9,10‐diyl). The UV‐visible spectrum of (Oligo‐ANT‐b‐P3HT) in solution shows broad absorption with two sets of absorption from both anthracene and thiophene core units, covering a wide range of the visible spectrum. The test devices of the blends of polymeric dyad with fullerene C61 (PCBM) show improved photovoltaic performance with a power conversion efficiency of 3.26% upon subjecting to pre‐fabrication thermal treatments. With optimized morphology of the interpenetrating network and the shorter fluorescence lifetime of the annealed dyad/PCBM blends, the effective charge transfer from the donor dyad to PCBM has evidenced. Thus, these studies will allow further synthetic advances to make potential high crystalline polymeric dyads with significantly improved light harvesting capability. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 3032–3045  相似文献   

3.
Self‐assembly of nanoparticles (NPs) into nonclose‐packed (ncp), semi‐two‐dimensional (2D) arrays is of interest in a variety of applications. Of special interest are photochemically active surfactant‐like fullerene derivatives [6,6]‐phenyl‐C61‐butyric acid methyl ester (PCBM). The study presented here characterizes the morphology and structure of patterns formed by a mixture of PCBM NP and an amphiphilic block‐copolymer tethered at the water–air interface (a surface brush) as a function of the concentration of poly(ethylene oxide) (PEO) dissolved in the liquid subphase. Theoretical modeling of the system shows that the concentration of PEO in the subphase mediates the dimensions of the surface brush and at high PEO concentrations induces a collapse of the brush at the solution–air interface. The state of the surface brush is suggested to tune the semi‐2D patterns observed in the experiments via lateral depletion interactions and, in particular, induce lateral phase separation of the PCBM‐block copolymer. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011  相似文献   

4.
The effect of replacing [6,6]‐phenyl‐C61 butyric acid methyl ester (PCBM) by its multiadduct analogs (bis‐PCBM and tris‐PCBM) in bulk heterojunction organic solar cells with poly(3‐hexylthiophene‐2,5‐diyl) (P3HT) is studied in terms of blend film microstructure, photophysics, electron transport properties, and device performance. Although the power conversion efficiency of the blend with bis‐PCBM is similar to the blend with PCBM, the performance of the devices with tris‐PCBM is considerably lower as a result of small photocurrent. Despite the lower electron affinity of the fullerene multiadducts, μs‐ms transient absorption measurements show that the charge generation efficiency is similar for all three fullerenes. The annealed blend films with multiadducts show a lower degree of fullerene aggregation and lower P3HT crystallinity than the annealed blend films with PCBM. We conclude that the reduction in performance is due largely to poorer electron transport in the blend films from higher adducts, due to the poorer fullerene network formation as well as the slower electron transport within the fullerene phase, confirmed here by field effect transistor measurements. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2010  相似文献   

5.
A key challenge to the development of polymer‐based organic solar cells is the issue of long‐term stability, which is mainly caused by the unstable time‐dependent morphology of active layers. In this study, poly(3‐hexylthiophene) (P3HT)/[6,6]‐phenyl C60‐butyric acid methyl ester (PCBM) blend is used as a model system to demonstrate that the long‐term stability of power conversion efficiency can be significantly improved by the addition of a small amount of amorphous regiorandom P3HT into semicrystalline regioregular one. The optical properties measured by UV–vis absorption and photoluminescence reveal that regiorandom P3HT can intimately mix with PCBM and prevent the segregation of PCBM. In addition, X‐ray scattering techniques were adopted to evidence the retardation of phase separation between P3HT and PCBM when regiorandom P3HT is added, which is further confirmed by optical microscopy that shows a reduction of large PCBM crystals after annealing at high temperature in the presence of regiorandom P3HT. The improvement of the long‐term stability is attributed to the capability of amorphous P3HT to be thermodynamically miscible with PCBM, which allows the active layer to form a more stable structure that evolves slower and hence decelerates the device decay. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 975–985  相似文献   

6.
Regioregular poly(3‐hexylthiophene)‐b‐poly(1H,1H‐dihydro perfluorooctyl methacrylate) (P3HT‐b‐PFOMA) diblock copolymers were synthesized by atom transfer radical polymerization of fluorooctyl methacrylate using bromoester terminated poly(3‐hexylthiophene) macroinitiators in order to investigate their morphological properties. The P3HT macroinitiator was previously prepared by chemical modification of hydroxy terminated P3HT. The block copolymers were well characterized by 1H NMR spectroscopy and gel permeation chromatography. Transmission electron microscopy was used to investigate the nanostructured morphology of the diblock copolymers. The block copolymers are able to undergo microphase separation and self‐assemble into well‐defined and organized nanofibrillar‐like micellar morphology. The development of the morphology of P3HT‐b‐PFOMA block copolymers was investigated after annealing in solvent vapor and also in supercritical CO2. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011  相似文献   

7.
Novel block copolymers, poly(3‐hexylthiophene)‐b‐poly(ethylene oxide) (P3HT‐b‐PEO) were synthesized via Suzuki coupling reaction of P3HT and PEO homopolymers. The copolymers were characterized by NMR, gel permeation chromatography, differential scanning calorimeter, and UV–vis measurements. A series of devices based on the block copolymers with a fullerene derivative were evaluated after thermal or solvent annealing. The device using P3HT‐b‐PEO showed higher efficiency than using P3HT blend after thermal annealing. Phase‐separated structures in the thin films of block copolymer blends were investigated by atomic force microscopy to clarify the relationship between morphologies constructed by annealing and the device performance. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011  相似文献   

8.
Poly(3‐hexylthiophene)/single‐walled carbon nanotube (P3HT/SWNT) materials are synthesized using an insitu Grignard metathesis approach. The structural properties and photophysics of the materials are studied using a multitude of techniques, including 1H NMR, FTIR, UV–vis absorption, Raman, photoluminescence (PL), and transient absorption spectroscopies. P3HT/SWNT composites with high P3HT regioregularity (rr > 96%) are observed. Raman spectroscopic data on the solid samples reveals an increase in the dispersion rate parameter with increasing SWNT concentration, thereby indicating close overlap and strong interactions between P3HT and the carbon nanotubes. Changes in the solution‐phase PL quantum yields and excited‐state lifetimes relative to pure P3HT support these conclusions, and indicate that strong interactions persist even after the composites are dispersed in organic solvents. The high regioregularity and enhanced P3HT–SWNT interactions are promising attributes for improving the morphology and efficiency of functional P3HT/SWNT materials. © 2013 Wiley Periodicals, Inc. J. Polym. Sci. Part B: Polym. Phys. 2014 , 52, 310–320  相似文献   

9.
We report the synthesis, morphology, and charge‐transporting characteristics of new crystalline–crystalline diblock copolymers, poly(3‐hexylthiophene‐block‐stearyl acrylate) (P3HT‐b‐PSA). Three different diblock copolymers, P1 , P2 , and P3 , with P3HT/PSA polymerization degree block ratios of 60/26, 60/50, and 60/360, respectively, were prepared for investigating the morphology‐property relationship and the dependence of optoelectronic properties on the block copolymer structure. Small‐ and wide‐angle X‐ray scattering indicated the presence of both P3HT and PSA crystalline domains and the presence of microphase separation among blocks. The transmission electron microscopy and atomic force microscopy results revealed that the diblock copolymers cast from chlorobenzene, tended to form needle‐like morphologies. The field‐effect mobilities of the diblock copolymers deposited on untreated SiO2 substrates, decreased with increasing PSA block length. In a sharp contrast, the mobilities enhanced with increasing PSA content when the P3HT‐b‐PSA was deposited on phenyltrichlorosilane (PTS)‐treated substrates. The copolymers with a 60/360 P3HT/PSA ratio showed a good mobility of 4 × 10?3 cm2 V?1 s?1 and a high on/off ratio of 7 × 106 on PTS‐treated substrates. This study highlighted the importance of the block ratio, the substrate and self‐assembly structures on the charge transport characteristics of the crystalline–crystalline conjugated diblock copolymers. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012  相似文献   

10.
It is known that poly(3‐alkylthiophene) (P3AT) side‐chain length notably influences the photovoltaic performances of relating devices. However, comprehensively study on its impact on the structures of P3ATs and their blends with [6, 6]‐phenyl‐C61 butyric acid methyl ester (PCBM) is insufficient. By using solid‐state NMR and FTIR techniques, four P3ATs and their PCBM blends are investigated in this work, focusing on the phase structures as modulated by side‐chain length. Recently, we revealed multiple crystalline main‐chain packings of packing a and b together with a mesophase in poly(3‐butylthiophene) (P3BT) films (DOI: 10.1021/acs.macromol.6b01828). Here, the semicrystalline structures are investigated on poly(3‐hexylthiophene) (P3HT), poly(3‐octylthiophene) (P3OT), and poly(3‐dodecylthiophene) (P3DDT) with traditional form I modification, where packing a and the amorphous phase are probed. Furthermore, crystallized side chain within packing a is detected in both P3OT and P3DDT films, which shows a FTIR absorption at 806 cm−1. Structural studies are also conducted on P3AT:PCBM blends. Compared with the pure P3ATs, the polymer crystallinities of the blends show reduction of about 40% for P3OT and P3DDT, whereas only about 10% for P3HT. Moreover, in P3BT:PCBM and P3HT:PCBM, the crystalline polymers and PCBM are phase separated, while in P3OT:PCBM and P3DDT:PCBM, blend components are mostly miscible. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018 , 56, 751–761  相似文献   

11.
New conjugated oligomers, oligo(9,9‐didodecylfluorene‐bis‐sulphurdiimide), consisting of 9,9‐didodecylfluorene separated by ? N?S?N? moieties, are reported. These oligomers are stable purple solids under ambient conditions with absorption covering a broad spectral window in the UV‐vis range and a main broad peak centered at 555 nm with onset extending to 700 nm. These oligomers show an obviously longer conjugation length than its dimeric analogue, bis‐9,9‐didodecyl‐fluorene‐2‐sulfurdiimide that shows a band‐edge absorption centered at 484 nm with onset at 590 nm. The dimer and oligomers are soluble in a variety of organic solvents. Moreover, we found that the oligomer with an average repeating‐unit number of six could significantly quench the photoluminescence (PL) of poly[2‐methoxy‐5‐(2′‐ethyl‐hexyloxy)‐1,4‐phenylene vinylene] (MEH‐PPV) or poly(3‐hexylthiophene) (P3HT) in the solid state. More importantly, the composites of this oligomer with P3HT showed a nearly 10‐fold enhancement of the photocurrent, compared with that of P3HT itself. In addition, the PL of this oligomer could be quenched by the presence of phenyl‐C61‐butyric acid methyl ester (PCBM) in toluene. These results suggest the presence of photoinduced charge transfer in composites of these oligomers blended with an electronic partner that either donates or accepts electrons. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011  相似文献   

12.
The effect of pyrene distribution within pyrene‐functionalized random and block copolymers on noncovalent polymer/single‐walled carbon nanotube (SWNT) interactions was investigated. The block copolymers served as superior solubilizing agents in comparison with the random copolymers. Also, increasing the pyrene content within a polymer, while a constant molecular weight was maintained, improved SWNT solubility and therefore had to result in stronger polymer–nanotube interactions. However, increasing the length of the pyrene‐containing block diminished nanotube solubility, likely because of a lower number of polymer chains that were capable of binding to the nanotube surface. Atomic force microscopy and transmission electron microscopy indicated that the polymer–SWNT interactions were capable of partially debundling the nanotubes into individual solvated structures. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1941–1951, 2006  相似文献   

13.
Charge transfer behavior of Poly(3‐hexylthiophene) (P3HT) and [6,6]‐phenyl‐C61‐butyric acid methyl eser (PCBM) in solutions and in films were examined by photoluminescence (PL) spectroscopy. PL study in solutions indicated that separation distance between P3HT and PCBM affected charge transfer efficiency more seriously than the interface area issue between P3HT and PCBM. P3HT/PCBM film showed very effective photo‐induced charge transfer before post‐thermal annealing on the bi‐layer P3HT/PCBM film. Charge transfer efficiency was gradually diminished by the annealing‐induced phase separation between P3HT and PCBM as revealed by increasing PL emission intensity of P3HT.  相似文献   

14.
Self‐assembly of poly(3‐hexylthiophene) ( P3HT) driven by π–π stacking, combined with “Host‐Guest Chemistry” of ethylene glycol oligomer and lithium ion is demonstrated using a thiophene‐based all conjugated amphiphilic block copolymer, containing 93 mol % of P3HT and 7 mol % of poly(3‐(2‐(2‐{2‐[2‐(2‐methoxy‐ethoxy)‐ethoxy]‐ethoxy}‐ethyl))thiophene), P3EGT blocks. An ion chelating ability of ethylene glycol oligomers with lithium ions in the P3EGT block is confirmed using 1H‐NMR spectrometry. This method could allow positioning lithium ions at the interface between P3HT domains and PC61BM clusters, confirmed using XRD and photoluminescence quenching experiments. The compact lamellar P3HT domains by side repulsion driven self‐assembly of amphiphilic block copolymer and the molecular engineering of the interface with an optimized lithium contents are resulted in the improvement of photovoltaic performance in an organic solar cell (2.1–3.0%). © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 1068–1074  相似文献   

15.
We present a dual length morphological model for the active layer of bulk‐heterojunction, polymer‐based solar cells using results from neutron and X‐ray scattering techniques. Two critical characteristic lengths are found in the mixtures composed of poly(3‐hexylthiophene) (P3HT) and [6,6]‐phenyl‐C61‐butyric acid methyl ester (PCBM). A characteristic length at 15 nm is the local characteristic of the P3HT crystals and PCBM agglomerations, which is independent of the bulk composition upon relaxation by thermal annealing. Conversely, a larger bicontinuous structure described by Teubner–Strey model with phase distances between 23 and 35 nm forms only after thermal annealing, which is highly correlated to the bulk compositions. These results suggest phase separation between the polymer and fullerene can only be partially manipulated by simple processing techniques such as coating conditions and annealing, and a more rigorous design of the morphology should be implemented in the future. © 2013 Wiley Periodicals, Inc. J Polym Sci Part B: Polym. Phys. 2014 , 52, 387–396  相似文献   

16.
In this study, the maleimide‐thiophene copolymer‐functionalized graphite oxide sheets (PTM21‐GOS) and carbon nanotubes (PTM21‐CNT) were developed for polymer solar cell (PSC) applications. The grafting of PTM21‐OH onto the CNT and GO sheets was confirmed using FTIR spectroscopy. PTM21‐CNT and PTM21‐GOS exhibited excellent dispersal behavior in organic solvents. Better thermal stability was observed for PTM21‐CNT and PTM21‐GOS as compared with that for PTM21‐OH. In addition, the optical band gaps of PTM21‐GOS and PTM21‐CNT were lower than that of PTM21‐OH. We incorporated PTM21‐GOS and PTM21‐CNT individually into poly(3‐hexylthiophene) (P3HT)/[6,6]‐phenyl‐C61‐butyric acid methyl ester (PCBM) blends for use as photoconversion layers of PSCs. Good distributional homogeneity was observed for PTM21‐GOS or PTM21‐CNT in the P3HT/PCBM blend film. The UV–vis absorption peaks of the blend films red‐shifted slightly upon increasing the content of PTM21‐GOS or PTM21‐CNT. The band gap energies and LUMO/HOMO energy levels of the P3HT/PTM21‐GOS and P3HT/PTM21‐CNT blend films were slightly lower than those of the P3HT film. The conjugated polymer‐functionalized PTM21‐GOS and PTM21‐CNT behaved as efficient electron acceptors and as charge‐transport assisters when incorporated into the photoactive layers of the PSCs. PV performance of the PSCs was enhanced after incorporating PTM21‐GOS or PTM21‐CNT in the P3HT/PCBM blend. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2013  相似文献   

17.
In this article, the synthesis of a series of conjugated rod–rod block copolymers based on poly(3‐hexylthiophene) (P3HT) and poly(phenyl isocyanide) (PPI) building blocks in a single pot is presented. Ni‐catalyzed Grignard metathesis polymerization of 2,5‐dibromo‐3‐hexylthiophene and subsequent addition of 4‐isocyanobenzoyl‐2‐aminoisobutyric acid decyl ester in the presence of Ni(dppp)Cl2 as a single catalyst afford P3HT‐b‐PPI with tunable molecular weights and compositions. In solid state, microphase separation occurred as differential scanning calorimetric analysis of P3HT‐b‐PPI revealed two glass transition temperatures. In solutions, the copolymers can self‐assemble into spherical aggregates with P3HT core and PPI shell in tetrahydrofuran and exhibit amorphous state in CHCl3. However, atomic force microscopy revealed that the block copolymers self‐assemble into nanofibrils on the substrate. These unique features warrant the resultant conjugated rod–rod copolymers' potential study in organic photovoltaic and other electronic devices. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 2939–2947  相似文献   

18.
Donor–acceptor block copolymers (BCP), incorporating poly(3‐hexylthiophene) (P3HT), and a polystyrene copolymer with pendant fullerenes (PPCBM) provide desired stable nanostructures, but mostly do not exhibit balanced charge carrier mobilities. This work presents an elegant approach to match hole and electron transport in BCP by blending with molecular PCBM without causing any macrophase separation. An insufficient electron mobility of PPCBM can be widely compensated by adding PCBM which is monitored by the space‐charge limited current method. Using X‐ray diffraction, atomic force microscopy, and differential scanning calorimetry, we verify the large miscibility of the PPCBM:PCBM blend up to 60 wt % PCBM load forming an amorphous, molecularly mixed fullerene phase without crystallization. Thus, blending BCP with PCBM substantially enhances charge transport achieving an electron mobility of μe=(3.2 ± 1.7) × 10?4 cm2V?1s?1 and hole mobility of μh=(1.8 ± 0.6) × 10?3 cm2V?1s?1 in organic field‐effect transistors (OFET). The BCP:PCBM blend provides a similarly high ambipolar charge transport compared to the established P3HT:PCBM system, but with the advantage of an exceptionally stable morphology even for prolonged thermal annealing. This work demonstrates the feasibility of high charge transport and stable morphology simultaneously in a donor–acceptor BCP by a blend approach. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 1125–1136  相似文献   

19.
Conjugated block copolymers consisting of poly(3‐hexyl thiophene) (P3HT) and a thermoresponsive polymer poly(N‐isopropyl acrylamide) (PNIPAM) with varying composition have been synthesized by facile click reaction between alkyne terminated P3HT and azide terminated PNIPAM. The composition‐dependent solubility, thermoresponsive property in water, phase behavior, electrochemical, optical, and electronic properties of the block copolymers were systematically investigated. The block copolymers with higher volume fraction of PNIPAM form thermoresponsive spherical micelles with P3HT‐rich crystalline cores and PNIPAM coronas. Both X‐ray and atomic force microscopic studies indicated that the blocks copolymers showed well‐defined microphase separated nanostructures and the structure depended on the composition of the blocks. The electrochemical study of the block copolymers clearly demonstrated that the extent of charge transport through the block copolymer thin film was similar to P3HT homopolymer without any significant change in the band gap. The block copolymers showed improved or similar charge carrier mobility compared with the pure P3HT depending on the composition of the block copolymer. These P3HT‐b‐PNIPAM copolymers were interesting for fabrication of optoelectronic devices capable of thermal and moisture sensing as well as for studying the thermoresponsive colloidal structures of semiconductor amphiphilic systems. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 1785–1794  相似文献   

20.
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