Temperature dependence of photoluminescence in MEH-PPV blend films

Quan, Shanyu; Feng, Tao; Xu, Zheng; Liu, Qian; Zhang, Ting; Liu, Deang; Hou, Yuhan; Wang, Yongsheng; Xu, Xurong

doi:10.1016/j.jlumin.2006.01.363

Cited by 17 publications

(12 citation statements)

References 25 publications

(25 reference statements)

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“…[7,42,63,72,73] In our data S apparent decreases upon increasing the doping level of PCBM up to 50 wt %, which suggests that the effective conjugation length and exciton migration in the PCBM doped MEH-PPV nanoparticles are enhanced. This interpretation contradicts the observed blue shifts of the emission maxima with increasing PCBM doping levels.…”

Section: Franck-condon Analysis Of Single Particle Spectramentioning

confidence: 47%

“…Literature reports support the notion that a blue shift of emission spectra is expected for MEH-PPV blends and a reduction in exciton migration was observed with increasing amounts of dopants. [7,63,65,66] This conclusion is further corroborated by fitting the Franck-Condon model to the emission spectra of single composite nanoparticles, using Equation (4) in a nonlinear least squares fitting procedure:…”

Section: Franck-condon Analysis Of Single Particle Spectramentioning

confidence: 66%

“…The Huang-Rhys factor has been shown to represent the extent of conjugation and exciton migration in conjugated polymers. [7,42,63,72,73] It can therefore be concluded that the increasing trend of S blue with increasing PCBM doping level indicates reduced exciton migration and increased self trapping of excitons, which corroborates that interchain aggregation is being hindered by the presence of PCBM. In addition, the subsequent decrease of S blue at 75 wt % PCBM doping further supports the notion that phase separation occurs at these high doping levels, leading to conjugated polymer regions in the nanoparticle that are apparently less heavily doped and thus have a larger occurrence of aggregation interactions between polymer chains and consequently enhanced exciton migration properties.…”

Section: Single-particle Ensemblesmentioning

confidence: 69%

“…Quan et al showed that the relative intensity of 0-1 vibronic peak compared to the 0-0 vibronic peak is suppressed in MEH-PPV films upon addition of PBD at low temperature. [63] These observations were attributed to changes in exciton migration with film composition. Marletta et al studied blended films of MEH-PPV in polystyrene (PS) at low temperature.…”

Section: Introductionmentioning

confidence: 99%

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Effect of PCBM Concentration on Photoluminescence Properties of Composite MEH‐PPV/PCBM Nanoparticles Investigated by a Franck–Condon Analysis of Single‐Particle Emission Spectra

Tenery

Gesquiere

2009

ChemPhysChem

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The emission of composite conjugated polymer (MEH-PPV)/fullerene (PCBM) nanoparticles is investigated by single particle spectroscopy (SPS), and changes in vibronic structure with nanoparticle composition are evaluated by means of a detailed Franck-Condon analysis. Consistent with previous reports we find that the emission spectra can be modeled as the superposition of two types of emitters, one with aggregate character and one with molecular character. Major findings from the fitting of the SPS data to a Franck-Condon model are that 1) the occurrence of each of the two types of emitters changes with nanoparticle composition to the point that no aggregate emitters are detected (at 50 wt% PCBM), 2) at the highest PCBM doping levels (75 wt% PCBM) aggregate emitters reappear due to nanoscale phase separation in the composite nanoparticles, 3) the molecular emitters show small Huang-Rhys factors that increase with PCBM doping, indicative of extensive delocalization and exciton migration that is reduced by the disorder introduced in the polymer material by PCBM doping and 4) the aggregate emitters show large Huang-Rhys factors, indicative of the localized nature of these energy trap sites, with a broad distribution of values of these Huang-Rhys factors. The latter observation suggests a broad heterogeneous distribution of aggregate morphologies in blended conducting polymer materials, which can be attributed to variations in polymer chain folding and stacking at the aggregate sites. The reported results obtained by the SPS approach show how blending conjugated polymers with fullerenes at various doping levels induces changes in interchain interactions and aggregate site density even at length scales below a few tens of nanometers that affect conjugated polymer material properties, an observation that has gone unnoticed in bulk studies of blended conjugated polymer films.

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Section: Franck-condon Analysis Of Single Particle Spectramentioning

confidence: 47%

Section: Franck-condon Analysis Of Single Particle Spectramentioning

confidence: 66%

Section: Single-particle Ensemblesmentioning

confidence: 69%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Effect of PCBM Concentration on Photoluminescence Properties of Composite MEH‐PPV/PCBM Nanoparticles Investigated by a Franck–Condon Analysis of Single‐Particle Emission Spectra

Tenery

Gesquiere

2009

ChemPhysChem

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“…They are also used for material research for preparation of organic light emitting diode, photoluminescence polymers etc [19][20][21][22] . Keeping the above fact in view we report facile synthesis of 2-amino-5-substituted phenyl-1,3,4-oxadiazoles using the microwave and conventional methods.…”

Section: Introductionmentioning

confidence: 99%

A Facile Microwave Assisted Synthesis and Spectral Analysis of 2-Amino-5-substituted phenyl-1,3,4-Oxadiazoles

Kumar¹,

Yadav²,

Jadon³

et al. 2012

Orientjchem.

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Synthetic organic chemists explore new methods for chemical transformation. In recent year lot of work has been carried out to use microwave irradiation as an alternative to conventional heating which provide higher yield and cleaner product. ABSTRACTAn efficient synthesis for the preparation of some 2-amino-5-substituted phenyl-1,3,4-oxadiazoles by using both conventional and microwave method have been devised. The obtained results revealed that, microwave assisted technique is efficient, eco-friendly and inexpensive method which not only give higher yield but also reduces the reaction time significantly. The resulting compounds were characterized by IR, 1 H-NMR, UV-Vis and mass spectral analysis.

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Theoretical study of electronic properties of organic photovoltaic materials

et al. 2008

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It has been proved that fullerene derivatives, in which an oligophenylenevinylene (OPV) group is attached to C(60), present an interesting photophysical phenomenon and can be incorporated into photovoltaic cells. In these systems, the OPV acts as electron donor upon excitation, and then fullerene absorbs photoexcited electrons. These new organic semiconductor materials offer the prospect of lower manufacturing costs and they present several advantages: easy fabrication, large area, flexible and light weight devices when compared with inorganic counter parts. In the present theoretical study, oligomeric chains of p-phenylenevinylene (n-PPV, n = 3-8 units) and C(60)-OPV hybrids have been studied by density functional theory (DFT). Electronic properties such as electronic absorption and emission spectra were calculated in order to determinate how the increment of spectroscopic units affects their electronic behavior. These properties were carried out with time dependent-density functional theory (TD-DFT) and ZINDO semiempirical method. The theoretical calculations of the structural properties of n-PPV and fullerene-OPV hybrids were obtained using PBE1PBE/6-31G and ONIOM two-layered version, respectively. All calculations were done with Gaussian 03W program package.

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Temperature dependence of photoluminescence in MEH-PPV blend films

Cited by 17 publications

References 25 publications

Effect of PCBM Concentration on Photoluminescence Properties of Composite MEH‐PPV/PCBM Nanoparticles Investigated by a Franck–Condon Analysis of Single‐Particle Emission Spectra

Effect of PCBM Concentration on Photoluminescence Properties of Composite MEH‐PPV/PCBM Nanoparticles Investigated by a Franck–Condon Analysis of Single‐Particle Emission Spectra

A Facile Microwave Assisted Synthesis and Spectral Analysis of 2-Amino-5-substituted phenyl-1,3,4-Oxadiazoles

Theoretical study of electronic properties of organic photovoltaic materials

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