Interchain photoluminescence in poly(phenylene vinylene) derivatives

Conwell, E. M.; Perlstein, Jerry; Shaik, Sason

doi:10.1103/physrevb.54.r2308

Cited by 91 publications

(77 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In addition, they also concluded that although the most excitations created by above-band-gap incident photons form polaron pairs (charges are created on adjacent conjugated chain segments and bound as a pair of polarons due to the Coulombic force) 22 or excimers in the two polymers, only those in CN-PPV emit lights because its smaller interchain distance results in a much larger matrix element for emission. However, in contrast to the calculation result of Conwell's group, 4 Rothberg's group found that there is long-lived emission (its lifetime is 425 ns and its spectrum ranges from 560 nm to 920 nm) in MEH-PPV film (spincasting from its tetrahydrofuran (THF) solution) from excimers at room temperature or low temperature (77 K) and estimated that the quantum yield for excimer formation is as high as 50%. 5 The excimers tend to be non-emissive at ambient temperatures and thus lower the corresponding de- vice performance.…”

Section: -2 Excimer Exciplex and Aggregate Formation In Conjugatementioning

confidence: 81%

A Review on the Emitting Species in Conjugated Polymers for Photo‐ and Electro‐luminescence

Chen¹,

Jen²,

Lu³

2010

J Chinese Chemical Soc

View full text Add to dashboard Cite

In conjugated polymers, fluorescence from a single polymer chain, which is contrasted with measurements on an ensemble or bulk collection of molecules, can provide important information about conformation of single polymer chain and energy transfer between different conjugation length segments within single polymer chain. On the other hand, the presence of intrachain or interchain interactions plays an important role on their photoluminescence (PL) and electroluminescence (EL) properties. In addition to non-interacting isolated chain, there are five interacting emitting species, namely: photo-excited dimers including excimer and exciplex, electrical-excited dimers including electromer and electroplex, and aggregate. Excimer, exciplex, and aggregate can lead to a generation of new peak with featureless structure on the longer wavelength side in the fluorescence spectrum and usually cause a lowering in PL quantum efficiency. These three emitting species can be observed in both PL and EL spectra. In addition, electromer and electroplex only appear in EL spectrum but not in PL spectrum. The presence of electromer and electroplex also leads to a new peak at longer wavelength side. Another non-interacting ground-state emitting species, b phase, consists of a chain segment with a more coplanar conformation and therefore results in a longer conjugation and clear vibronic transitions.

show abstract

Section: -2 Excimer Exciplex and Aggregate Formation In Conjugatementioning

confidence: 81%

A Review on the Emitting Species in Conjugated Polymers for Photo‐ and Electro‐luminescence

Chen¹,

Jen²,

Lu³

2010

J Chinese Chemical Soc

View full text Add to dashboard Cite

show abstract

“…47 These states significantly affect absorption/emission properties of molecules. 47 These results 46,47 clearly indicate the necessity of further investigation of the dependence on the distance between chromophores, and how this affects the electronic structure of the aggregate.…”

Section: Introductionmentioning

confidence: 93%

“…Monte Carlo simulations of the chain packing in the different PPV derivatives resulted in 3.3-4.2 Å interchain separations. 46 An experimental/theoretical study of the family of stilbenoid dimers bound to a paracyclophane core showed that new interchromophore states with strong electron exchange appear at smaller distances. 47 These states significantly affect absorption/emission properties of molecules.…”

Section: Introductionmentioning

confidence: 99%

Interchain Electronic Excitations in Poly(phenylenevinylene) (PPV) Aggregates

et al. 2000

View full text Add to dashboard Cite

The semiempirical collective electronic oscillators (CEO) approach based on a time-dependent HartreeFock approximation is applied to analyze formation of interchain electronic excitations in PPV aggregates composed of two weakly coupled chain segments. Real-space analysis of transition density matrices identifies the origins of electron-hole pairs created upon optical excitation. The singlet intrachain excitons are delocalized along the whole oligomer chain and manifest themselves as strong band edge transitions in the linear spectra. New low-frequency interchain electronic excitations appear upon bringing oligomer chains into close proximity (3-4 Å). These new electronic states localized at the near-contact have no signatures in linear absorption. We argue that they may significantly decrease luminescence quantum efficiency of polymer films.

show abstract

“…Cyano-substituted poly(p-phenylene vinylene) (CN-PPV) is a conjugated polymer that was first developed as a highelectron-affinity polymer for organic light-emitting diodes (OLEDs) 12 . It has a planar backbone with long alkoxy side groups 13 and strong electron withdrawing cyano (CN) groups that lead to strong intermolecular interactions [14][15][16] . The red or near-infrared luminescence emission 16 of CN-PPV-based materials led to their use in cell labelling [17][18][19] , protein The material composition of CPNs influences their properties in biological fluids and cell culture media.…”

Section: Introductionmentioning

confidence: 99%

Bright conjugated polymer nanoparticles containing a biodegradable shell produced at high yields and with tuneable optical properties by a scalable microfluidic device

et al. 2017

View full text Add to dashboard Cite

This study compares the performance of a microfluidic technique and a conventional bulk method to manufacture conjugated polymer nanoparticles (CPNs) embedded within a biodegradable poly(ethylene glycol) methyl ether-blockpoly(lactide-co-glycolide) (PEG5K-PLGA55K) matrix. The influence of PEG5K-PLGA55K and conjugated polymers cyanosubstituted poly(p-phenylene vinylene) (CN-PPV) and poly(9,9-dioctylfluorene-2,1,3-benzothiadiazole) (F8BT) on the physicochemical properties of the CPNs was also evaluated. Both techniques enabled CPN production with high end product yields (~70-95%). However, while the bulk technique (solvent displacement) under optimal conditions generated small nanoparticles (~70-100 nm) with similar optical properties (quantum yields ~35%), the microfluidic approach produced larger CPNs (140-260 nm) with significantly superior quantum yields (49-55%) and tailored emission spectra. CPNs containing CN-PPV showed smaller size distributions and tuneable emission spectra compared to F8BT systems prepared under the same conditions. The presence of PEG5K-PLGA55K did not affect the size or optical properties of the CPNs and provided a neutral net electric charge as is often required for biomedical applications. The microfluidics flowbased device was successfully used for the continuous preparation of CPNs over a 24 hour period. On the basis of the results presented here, it can be concluded that the microfluidic device used in this study can be used to optimize the production of bright CPNs with tailored properties with good reproducibility.

show abstract

Interchain photoluminescence in poly(phenylene vinylene) derivatives

Cited by 91 publications

References 18 publications

A Review on the Emitting Species in Conjugated Polymers for Photo‐ and Electro‐luminescence

A Review on the Emitting Species in Conjugated Polymers for Photo‐ and Electro‐luminescence

Interchain Electronic Excitations in Poly(phenylenevinylene) (PPV) Aggregates

Bright conjugated polymer nanoparticles containing a biodegradable shell produced at high yields and with tuneable optical properties by a scalable microfluidic device

Contact Info

Product

Resources

About