Abstract Here, a general experimental method to determine the energy E CT of intermolecular charge‐transfer (CT) states in electron donor–acceptor (D–A) blends from ground state absorption and electrochemical measurements is proposed. This calibrated against photon maximum luminescence selected D–A correct for constant Coulombic term. It shown that correlates linearly with open‐circuit voltage ( V oc ) photovoltaic devices via eV = − 0.5 eV. Using energy, it found photoinduced transfer (PET)...

The electro-optical properties of thin films electron donor-acceptor blends a fluorene copolymer (PF10TBT) and fullerene derivative (PCBM) were studied. Transmission microscopy shows that in these nanocrystalline PCBM clusters are formed at high content. For all concentrations, charge transfer (CT) transition is observed with absorption spectroscopy, photoluminescence, electroluminescence. CT emission used as probe to investigate the dissociation excited states interface photovoltaic...

Comparative studies on hydrogen-bonded versus covalently linked donor-acceptor-donor dye arrays obtained from oligo(p-phenylene vinylene)s (OPVs) as donor and bay-substituted perylene bisimides (PERYs) acceptor dyes are presented. Both systems form well-ordered J-type aggregates in methylcyclohexane, but only afford hierarchically assembled chiral OPV-PERY superstructures consisting of left-handed helical pi-pi co-aggregates (CD spectroscopy) the two that further assemble into right-handed...

Abstract Organic photodetectors (OPDs) have gained increasing interest as they offer cost‐effective fabrication methods using low temperature processes, making them particularly attractive for large area image detectors on lightweight flexible plastic substrates. Moreover, their photophysical and optoelectronic properties can be tuned both at a material device level. Visible‐light OPDs are proposed use in indirect‐conversion X‐ray detectors, fingerprint scanners, intelligent surfaces gesture...

We demonstrate a facile route to obtain high and broad-band circular polarization of electroluminescence in single-layer polymer OLEDs. As light-emitting material we use donor–acceptor polyfluorene with enantiomerically pure chiral side-chains. show that upon thermal annealing the self-assembles into multidomain cholesteric film. By varying thickness emitting layer, achieve levels (up 40% excess right-handed polarization), which are highest reported for OLEDs not using dopants or alignment...

The nature of the solubilizing alkyl side chains has a strong effect on performance semiconducting diketopyrrolopyrrole polymers in organic solar cells with fullerene acceptors. relates to width semicrystalline polymer fibrils that form these blends. If fibril is wider than exciton diffusion length, fewer charges and efficiency drops.

Circularly polarized electroluminescence (CPEL) has potential application in optical data storage and processing. It was recently discovered that CPEL could be generated from chiral-substituted, conjugated polymers. These authors have synthesized a range of polyfluorenes (e.g., see Figure) form liquid crystals emit bluish light with significant (200 times greater than the first report) circularly component.

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTCircular Dichroism and Circular Polarization of Photoluminescence Highly Ordered Poly{3,4-di[(S)-2-methylbutoxy]thiophene}B. M. W. Langeveld-Voss, R. A. J. Janssen, P. T. Christiaans, S. C. Meskers, H. Dekkers, E. MeijerView Author Information Laboratory Organic Chemistry Eindhoven University Technology, P.O. Box 513 5600 MB Eindhoven, The Netherlands Leiden Institute Chemistry, Gorlaeus Laboratories University, 9502 2300 RA Leiden, Cite...

Butyl, hexyl, and decyl derivatives of the liquid-crystalline organic semiconductor 5,5' '-bis(5-alkyl-2-thienylethynyl)-2,2':5',2' '-terthiophene were synthesized studied with respect to their structural, optical, electrical properties. By means an optimized thermal annealing scheme hexyl compounds could be processed into self-assembled monodomain films up 150 mm in diameter. These investigated X-ray diffractometry, which revealed a clearly single-crystalline monoclinic morphology lamellae...

All lined up: Supramolecular assemblies are aligned by a convective flow in clear, nonviscous dilute solutions (see picture). The linear dichroism created the alignment results artifacts circular measurements, origins of which explained.

The self-assembly of alpha,alpha'-linked sexithiophenes with chiral and achiral penta(ethylene glycol) chains attached at the alpha-positions terminal rings, that is, 2,2':5',2'':5'',2''':5''',2'''':5'''',2'''''-sexithiophene-5,5'''''-dicarboxylic acid-2S)-2-methyl-3,6,9,12,15-pentaoxahexadecyl ester (1) 2,2':5',2'':5'',2''':5'''',2''''':5''''',2'''''-sexithiophene-5,5'''''-dicarboxylic acid-3,6,9,12,15-pentaoxahexadecyl (2), respectively is described. Analysis UV/vis, fluorescence, circular...

A Suzuki polycondensation reaction has been used to synthesize two copolymers consisting of alternating oligo(p-phenylene vinylene) (OPV) donor and perylene bisimide (PERY) acceptor chromophores. The differ by the length saturated spacer that connects OPV PERY units. Photoinduced singlet energy transfer photoinduced charge separation in these polychromophores have studied solution solid state via photoluminescence femtosecond pump-probe spectroscopy. In both polymers a electron occurs within...

The dynamic transfer of a conjugated polymer's organization-dependent properties from the solution state to solid film was probed by circularly polarized luminescence (CPL) and circular dichroism (CD) spectroscopy. Different supramolecular organizations within films aggregate solutions chiral poly(p-phenylenevinylene) derivative led opposite CPL CD spectra. These dramatic property differences were controlled regulating self-assembly through solvent selection annealing. Therefore, different...

In this work we present the preparation of highly luminescent anisotropic CdTe/CdSe colloidal heteronanocrystals. The reaction conditions used (low temperature, slow precursor addition, and surfactant composition) resulted in a tunable shape from prolate to branched nanocrystals. Upon CdSe shell growth heteronanocrystals show gradual evolution type-I type-II optical behavior. These remarkably high photoluminescence quantum yield (up 82%) negligible thermally induced quenching up temperatures...

The kinetics of photoinduced charge transfer reactions in covalently linked donor-acceptor molecules often undergoes dramatic changes when these self-assemble from a molecular dissolved state into nanoaggregate. Frequently, the origin is only partially understood. In this paper, we describe intermolecular spatial organization three homologous arrays, consisting central perylene bisimide (PERY) acceptor moiety and two oligo(p-phenylene vinylene) (OPV) donor units, nanoaggregates identify both...

The use of diiodooctane as processing additive for construction PCPDTBT:PCBM solar cells results in a profound change photophysical behavior this blend. In the improved morphology obtained with additive, recombination charge carriers to lowest triplet excited state is suppressed. This contributes boost power conversion efficiency induced by agent.

Carbon dots have recently emerged and gained much interest as a new class of carbon nanomaterials especially suited for biological applications owing to their characteristic advantages such non-toxicity, bio-compatibility, element abundance. In this study, fast effective method was developed the synthesis fluorescent by microplasma technology, at atmospheric pressure, using isopropanol only reactant. Characterizations synthesized including investigation structure, morphology optical...

Functional supramolecular systems like carbonyl-bridged triarylamine (CBT) trisamides are known for their long-range energy transport at room temperature. Understanding the complex self-assembly processes of this system allows control over generated structures using controlled polymerization. Here, we present two novel CBT with (S)- or (R)-chiral side chains which show a two-pathway behavior in solution. Depending on thermal profile during process, different stable states obtained under...

Abstract Polymorphism of organic semiconducting materials exerts critical effects on their physical properties such as optical absorption, emission and electrical conductivity, provides an excellent platform for investigating structure–property relations. It is, however, challenging to efficiently tune the polymorphism conjugated polymers in aggregated, semi-crystalline phases due conformational freedom anisotropic nature. Here, two distinctly different polymorphs ( β 1 2 ) a low-bandgap...

Abstract Minimizing the reverse bias dark current while retaining external quantum efficiency is crucial if light detection sensitivity of organic photodiodes (OPDs) to compete with inorganic photodetectors. However, a quantitative relationship between magnitude density under ( J d ) and properties bulk heterojunction (BHJ) active layer has so far not been established. Here, systematic analysis in state‐of‐the‐art BHJ OPDs using five polymers range energy levels charge transport...

Photophysical properties of diketopyrrolopyrrole derivatives substituted with oligothiophenes are investigated. All compounds found to be fluorescent both in solution and the solid phase. At low temperature solid, fluorescence originates from excimer-like excited states. Comparison absorption excitation spectra taken under matrix isolated conditions on films show presence J- H-type bands Quantum-chemical calculations, including exciton–phonon coupling account for deviations Born–Oppenheimer...

Hybrid organic-inorganic perovskites allow the synthesis of high-quality, nanostructured semiconducting films via easily accessible solution-based techniques. This has allowed tremendous development in optoelectronic applications, primarily solar cells and light-emitting diodes. Allowed by ease access to nanostructure, chirality recently been introduced as a promising way obtain advanced control charge spin for developing circularly polarized light sources. Circular polarization...

The field of supramolecular polymers is rapidly expanding; however, the exploitation these systems as functional materials still elusive. To become competitive, must display microstructural order and emergence new properties upon copolymerization. tackle this, a greater understanding relationship between monomers' design polymer microstructure required well set monomers that efficiently interact with one another to synergistically generate Here, we present first implementation frustrated...

Abstract Materials with highly ordered molecular arrangements have the capacity to display unique properties derived from their nanoscale structure. Here, synthesis and characterization of azobenzene (AZO)‐functionalized siloxane oligomers discrete length that form photoswitchable supramolecular materials are described. Specifically, synergy between phase segregation crystallization leads self‐assembly an exfoliated 2D crystal becomes isotropic upon photoisomerization UV light. Consequently,...

Abstract A facile route to soft matter self‐powered bulk heterojunction photodiode detectors sensitive the circular polarization state of light is shown based on intrinsic excitonic dichroism photoactive layer blend. As detecting materials, enantiopure semiconducting small molecular squaraine derivates opposite handedness are employed. Via Mueller matrix ellipsometry, proven be H‐type nature and not originating from mesoscopic structural ordering. Within green spectral range, photodiodes...