X-ray scattering from oriented poly(3-alkylthiophenes)

Mårdalen, Jostein; Samuelsen, Emil J.; Gautun, Odd R.; Carlsen, Per H. J.

doi:10.1016/0379-6779(92)90239-f

Cited by 109 publications

(80 citation statements)

References 19 publications

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“…As recognized in the early 1990s, the chemical incompatibility between the conjugated polythiophene backbone and alkyl side chains results in the build up of a layered ''selfassembled'' structure in which p-stacked polythiophene backbones alternate with layers of more or less ordered alkyl side chains [11][12][13] [see Fig. 1(a)].…”

Section: Polymorphismmentioning

confidence: 99%

Structure and morphology control in thin films of regioregular poly(3‐hexylthiophene)

Brinkmann

2011

J Polym Sci B Polym Phys

356

388

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This review focuses on the structural control in thin films of regioregular poly(3-hexylthiophene) (P3HT), a workhorse among conjugated semiconducting polymers. It highlights the correlation existing between processing conditions and the resulting structures formed in thin films and in solution. Particular emphasis is put on the control of nucleation, crystallinity and orientation. P3HT can generate a large palette of morphologies in thin films including crystalline nanofibrils, spherulites, interconnected semicrystalline morphologies and nanostructured fibers, depending on the elaboration method and on the macromolecular parameters of the polymer. Effective means developed in the recent literature to control orientation of crystalline domains in thin films, especially by using epitaxial crystallization and controlled nucleation conditions are emphasized.

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Section: Polymorphismmentioning

confidence: 99%

Structure and morphology control in thin films of regioregular poly(3‐hexylthiophene)

Brinkmann

2011

J Polym Sci B Polym Phys

356

388

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“…The way that the molecules order in the solid phase is of great importance as for example in the case of P3HT which orders in a lamellar structure. [67][68][69][70][71][72] …”

Section: Other Factorsmentioning

confidence: 99%

Low band gap polymers for organic photovoltaics

Bundgaard

Krebs

2007

Solar Energy Materials and Solar Cells

1,293

918

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i Several research groups within the area of organic photovoltaics are focusing on low band gap polymers, a type of polymer which absorbs light with wavelengths longer than 620 nm. These systems are believed to increase the efficiency of organic photovoltaics due to a better overlap of the absorption spectrum of the polymer with the solar spectrum. In this dissertation the synthesis of 16 new low band gap copolymers based on thiophene, benzothiadiazole and benzo-bis(thiadiazole) are described. The polymers have been prepared by two strategies; one using oxidative ferric chloride polymerization and one using Stille cross coupling polymerization. The polymers were purified chemically and by Size Exclusion Chromatography (SEC). The polymers were characterized by UV-vis and Ultraviolet Photoelectron Spectroscopy (UPS), and the optical band gap and the electronic structure of the polymer were determined. The copolymers show optical band gaps from 1.65 -2.0 eV for the copolymers of thiophene and benzothiadiazole, where a decrease in the band gap was observed with an increase in the number of thiophene units in the repeating unit (n = 1 -4). A band gap down to 0.65 eV was observed for the copolymers of thiophene and benzo-bis(thiadiazole). The film forming ability of the polymers was studied by attaching different alkyl side chains on the polymer back-bone, i.e. hexyl-, 2-ethylhexyl-, dodecyl-and 3,7,11-trimethyldodecyl-groups. The 3,7,11-trimethyldodecyl-group was found to give the best film forming ability and highest absorbance, when the polymer was spin coated from solvents like THF, chloroform and 1,2-dichlorobenzene. The copolymer of thiophene and benzothiadiazole with four thiophenes in the repeating unit and 3,7,11-trimethyldodecyl-group as side chains with a band gap of 1.65 eV was applied in organic photovoltaic devices with active areas of 0.1, 3 and 10 cm 2 . The morphology of the active layer was studied, and it was found that the morphology and the photovoltaic performance of the device was affected by the choice of solvent, the spin coating conditions, the concentration of polymer, the ratio between polymer and PCBM and the annealing temperature. The highest efficiency of 1 % was achieved when the ratio between the polymer and PCBM was 1:2 and the device was annealed at 110 ºC. Lifetime and incident photon to current efficiency (IPCE) of the devices are also described. Finally, the polymer was applied in hybrid PV devices based on ZnO nano-fibers and the results of these studies are given.ii Indenfor organisk solceller fokuseres i denne tid på polymere med lavt båndgap, dvs. polymerer som absorberer lys med bølgelaengder laengere end 620 nm. Disse lavbåndgabs polymere har vist sig at kunne øge effiktiviteten af organiske solceller ved et bedre overlap mellem polymerens absorptionsspektrum og solens spektrum. I denne afhandling beskrives syntesen af 16 nye lavbåndgabs copolymere som er baseret på thiophen, benzothiadiazol og benzo-bis(thiadiazol). Der blev benyttet to syntese strategier: én med oxydativ p...

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“…Certainly, some comments should be done concerning the relation between our model of PATs structure and conformation, and other models existing in the literature [1,4,11]. We think that each model has its own advantages and its own weak points.…”

Section: Discussionmentioning

confidence: 99%

“…It has to be noticed that, by several authors (see, for example [4]), the macroscopic properties of the polymer film strongly depend on the "quality" of the sample. It seems reasonably to believe that the crystallinity, the maximum stretch ratio, the molecular weight, the polydispersity, and other properties may depend on many factors, which one cannot fully control, and which may strongly influence the structural properties of polymer sample, causing an important difference between various samples of "the same" polymer.…”

Section: Discussionmentioning

confidence: 99%

“…The structure of pure and doped poΙy(3-alkylthiophenes) (PATS) has been investigated by many research workers because of its importance for the electronic and other physical properties of this class of conjugated polymers (see for example [1][2][3][4][5][6]); especially,'the works of Winokur and coworkers [7,8] have thrown the . light onto the structure properties of PATs.…”

Section: Introductionmentioning

confidence: 99%

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Effect of Uniaxial Stretching on Structural Properties of Poly(3-Alkylthiophenes)

Łużny

Zagórska

1997

Acta Phys. Pol. A

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The influence of uniaxial stretching on the molecular, structure of poly(3-alkylthiopahenes was studied with the use of X-ray diffraction. Three poly(3-alkylthiopahenes), namely these containing n-hexyl, n-octyl and n-decyl groups, were investigated. The samples were oriented by stretching and the diffraction patterns for two geometries of scattering were obtained for undoped samples. The comparison of experimental diffraction data for unoriented and oriented samples, gives information about the role of the side chains in the changes of molecular conformation induced by stretching of the polymer sample. Tle main conclusion of our work is that the process of orientation induces similar pahenomena in all samples studied, but the structural and conformation changes depend on the side chain length: the shorter the alkyl snbstituent, the easier the straightening of the main polymer chain. The authors suggest that uniaxial stretching of pοly(3-alkylthiophenes) changes the degree of main chain planarity. This effect can influence the π-conjugation in polymer system, which'may have great importance for any future application of poly(3-alkylthiopahenes). .

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X-ray scattering from oriented poly(3-alkylthiophenes)

Cited by 109 publications

References 19 publications

Structure and morphology control in thin films of regioregular poly(3‐hexylthiophene)

Structure and morphology control in thin films of regioregular poly(3‐hexylthiophene)

Low band gap polymers for organic photovoltaics

Effect of Uniaxial Stretching on Structural Properties of Poly(3-Alkylthiophenes)

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