10 research outputs found
Application of functional PPV-derivatives prepared via the sulfinyl precursor route as transducers in impedimetric biosensors
Tetra-alkoxy substituted PPV derivatives: a new class of highly soluble liquid crystalline conjugated polymers
2,5-substituted PPV-derivatives with different polarities: The effect of side chain polarity on solubility, optical and electronic properties
The relation between open-circuit voltage and the onset of photocurrent generation by charge-transfer absorption in polymer: Fullerene bulk heterojunction solar cells
Synthesis and characterization of high molecular weight phthalocyanine-PPV copolymers through post-polymerization functionalization
Evidence of the improvement of photovoltaic efficiency by polar molecule orientation in a new semiconducting polymer
International audienceStorage of an internal field in a polymeric semiconductor device should be of great interest for applications like photovoltaic solar cells to facilitate exciton dissociation and improve charge transport in the structure. Orientation of polar molecules, contained inside a polymer binder, induces a rectifying effect, behaving as a distributed homojunction within a single polymeric film. To investigate this concept, a new poly(p-phenylenevinylene) (PPV) derivative bearing push–pull like molecules was purposefully designed and synthesized. Effect of polar molecules’ orientation on carrier injection and transport properties was studied. In the test systems, we demonstrate an increase of the external quantum efficiency upon orientation
Evidence of the improvement of photovoltaic efficiency by polar molecule orientation in a new semiconducting polymer
International audienc
Strategy for Enhancing the Dielectric Constant of Organic Semiconductors Without Sacrificing Charge Carrier Mobility and Solubility
Current organic semiconductors for organic photovoltaics (OPV) have relative dielectric constants (relative permittivities, epsilon(r)) in the range of 2-4. As a consequence, Coulombically bound electron-hole pairs (excitons) are produced upon absorption of light, giving rise to limited power conversion efficiencies. We introduce a strategy to enhance epsilon(r) of well-known donors and acceptors without breaking conjugation, degrading charge carrier mobility or altering the transport gap. The ability of ethylene glycol (EG) repeating units to rapidly reorient their dipoles with the charge redistributions in the environment was proven via density functional theory (DFT) calculations. Fullerene derivatives functionalized with triethylene glycol side chains were studied for the enhancement of epsilon(r) together with poly(p-phenylene vinylene) and diketo-pyrrolopyrrole based polymers functionalized with similar side chains. The polymers showed a doubling of epsilon(r) with respect to their reference polymers in identical backbone. Fullerene derivatives presented enhancements up to 6 compared with phenyl-C-61-butyric acid methyl ester (PCBM) as the reference. Importantly, the applied modifications did not affect the mobility of electrons and holes and provided excellent solubility in common organic solvents