Crystalline Forms and Emission Behavior of Poly(9,9-di-<i>n</i>-octyl-2,7-fluorene)

Chen, S. H.; Su, and A. C.; Su, Chun‐Jen; Chen, S. A.

doi:10.1021/ma048162t

Cited by 228 publications

(305 citation statements)

References 29 publications

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“…37 The absorption spectrum of PF-BDAN was red-shifted and broadened, and the emissions spectrum was also red-shifted in the film. These results suggest the presence of significant interchain interactions in these polymers, supported by the X-ray diffraction patterns indicative of their planar β-phase, 49 and highlighting the planarity and intermolecular stacking of the PF backbones (Supplementary Figure S18). The small shoulder absorption band in the ultraviolet spectrum and clear vibrational structure in the photoluminescence (PL) spectrum of PF-BDAN arose from the pyrene moieties.…”

Section: %mentioning

confidence: 69%

“…In addition, the emission peak of PF-P in the film was similar to the peak obtained in CHCl 3 solution. The 2θ-value in the X-ray diffraction profile of PF-P is indicative of the α-phase, 49 suggesting that the PF backbones in PF-P are twisted (Supplementary Figure S18), leading to the blue-shifted absorption spectrum. Thus, the PFs of PF-P were layered in a single polymer chain; however, planarization of the PF backbones was prevented by the alkyl chains of neighboring PFs, the large excluded volume of which, in turn, inhibited the intermolecular interactions between their π-systems.…”

Section: %mentioning

confidence: 99%

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π-Conjugated polymer-layered structures: synthesis and self-assembly

Tsuji

Morisaki

Chujo

2016

Polym J

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π-Conjugated polymers capped with a boronic acid end-functional group were synthesized by chain-growth Suzuki-Miyaura polycondensation. The obtained polymers were reacted with a π-stacked-polymer scaffold, developed in our previous work. Despite their bulkiness, the conjugated polymers were efficiently introduced into the polymer scaffold. The spectroscopic and optical characterization of the obtained graft polymers in the solid state revealed that the original π-conjugated polymers were stacked in a single polymer chain. Although excluded volume effects prevented significant intermolecular interactions between the polyfluorenes, the introduced polythiophenes formed intermolecular π-stacked structures. Direct observations of the obtained graft polymers showed that the graft polymers self-assembled into the spherical or fiber structures depending on the introduced polymers, whereas no ordered structures were formed by the same polymers before the polymer reaction.

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Section: %mentioning

confidence: 69%

Section: %mentioning

confidence: 99%

π-Conjugated polymer-layered structures: synthesis and self-assembly

Tsuji

Morisaki

Chujo

2016

Polym J

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“…[ 38,45 ] This is very different from that of polycrystalline polymers such as P3HT, poly(9,9-dioctylfl uorene) (PFO), poly(9,9-dioctylfl uorene-alt -benzothiadiazole) (F8BT), and poly(9,9-dioctylfl uorene-alt -bithiophene), which can have rich and complex DSC spectra showing multiple peaks from glass, crystallization, and melting transitions. [ 36,[46][47][48][49][50][51] The thin fi lm optical absorption spectra of PFB and PFMO (Figure 2 resemble the solution spectra using a good solvent in which the chains are in the random-coil conformation. This is exactly as for TFB, being an expected characteristic of an amorphous semiconducting polymer.…”

Section: Resultsmentioning

confidence: 94%

“…[ 36 ] Polycrystalline polymers such as P3HT, F8BT, and PFO instead typically show a red shift of the absorption edge and/or more structure with vibrational sideband detail in their thin fi lm spectra compared to the good-solvent solution spectra. [ 17,36,47,48,[52][53][54] We additionally recorded the X-ray diffraction (XRD) data ( Figure S1, Supporting Information) of a 330 nm thick fi lm of PFB annealed for 1 h at 150 °C just above the glass transition temperature to encourage any potential crystallite formation (PFMO was not investigated due to limited material availability). Despite a relatively long scan time, the diffractogram showed no diffraction peaks, the spectrum being dominated by the background due to the glass substrate (we note that F8BT fi lms show clear diffraction peaks under the same experimental conditions with the same apparatus (see the Supporting Information of ref.…”

Section: Resultsmentioning

confidence: 99%

Charge‐Carrier Density Independent Mobility in Amorphous Fluorene‐Triarylamine Copolymers

Campbell

Rawcliffe

Guite

et al. 2016

Adv Funct Materials

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3720 wileyonlinelibrary.com (OPVs), and organic fi eld-effect transistors (OFETs). A crucial parameter in the development of these technologies is the OSC charge-carrier mobility, and how it is related to the different OSC materials, processing, device architectures, and device operating conditions. Many semiconducting polymers and small molecules are amorphous, and such disorder in the physical morphology is expected to refl ect itself in disorder of the energy levels of the hole and electron transport states ( Figure 1 a). Such energetic disorder will directly impact charge transport and mobility. [1][2][3][4][5][6][7][8][9][10][11][12] For such energetically disordered OSCs, one feature predicted by many charge transport models is a charge-carrier density dependent mobility. The original Gaussian disorder model (GDM) developed by Bässler for hopping transport in a Gaussian density of states (DOS) distribution was a single carrier approach, [ 1 ] as were the models based on it which considered both correlated energetic disorder, [ 2 ] with a smoothly varying energy landscape (see Figure 1 a), and the effect of polaronic relaxation. [ 3 ] The percolation model developed by Vissenberg and Matters for transport involving an exponential DOS instead considered multiple carriers, [ 4 ] and this predicted a mobility which has a power-law dependency on the charge-carrier density. The measured transistor mobility falls two to three orders of magnitude below that predicted from the charge-carrier density dependent model, and does not follow the expected power-law relationship. The experimental results for these two amorphous polymers are therefore consistent with a charge-carrier density independent mobility, and this is discussed in terms of polaron-dominated hopping and interchain correlated disorder.

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“…Taking into account these temperatures, we can conclude that the vinylene phenylene units decrease the temperature of all relaxation processes. According to X-ray diffraction results (data are not shown), BE329 is a semicrystalline polymer [7] while GE108 is completely amorphous, which explains the DMTA data. [9], which provide a measurement of the 13 C-1 H magnetic dipolar coupling of each chemical group.…”

Section: Resultsmentioning

confidence: 91%