Fullerene

About: Fullerene is a research topic. Over the lifetime, 12723 publications have been published within this topic receiving 359173 citations.

Enhanced Ambient Stability of Efficient Perovskite Solar Cells by Employing a Modified Fullerene Cathode Interlayer

Abstract: A novel fullerene cathode interlayer is employed to facilitate the fabrication of stable and efficient perovskite solar cells. This modified fullerene surfactant significantly increases air stability of the derived devices due to its hydrophobic characteristics to enable 80% of the initial PCE to be retained after being exposed in ambient condition with 20% relative humidity for 14 days.

Architectural engineering of rod-coil compatibilizers for producing mechanically and thermally stable polymer solar cells.

Abstract: While most high-efficiency polymer solar cells (PSCs) are made of bulk heterojunction (BHJ) blends of conjugated polymers and fullerene derivatives, they have a significant morphological instability issue against mechanical and thermal stress. Herein, we developed an architecturally engineered compatibilizer, poly(3-hexylthiophene)-graft-poly(2-vinylpyridine) (P3HT-g-P2VP), that effectively modifies the sharp interface of a BHJ layer composed of a P3HT donor and various fullerene acceptors, resulting in a dramatic enhancement of mechanical and thermal stabilities. We directly measured the mechanical properties of active layer thin films without a supporting substrate by floating a thin film on water, and the enhancement of mechanical stability without loss of the electronic functions of PSCs was successfully demonstrated. Supramolecular interactions between the P2VP of the P3HT-g-P2VP polymers and the fullerenes generated their universal use as compatibilizers regardless of the type of fullerene acceptors...

Liquid-crystalline fullerene-ferrocene dyads

Abstract: The 1,3-dipolar cycloaddition reaction was used to assemble fullerene, ferrocene and a second-generation liquid-crystalline cyanobiphenyl-based dendrimer. The targeted compound displayed an enantiotropic smectic A phase from 40 to 135 °C. The d-layer spacing was determined by X-ray diffraction, and was found to be independent of temperature with a value of 95 A. Molecular modeling and structural considerations suggested partial bilayer organization of the mesogenic molecular units within the smectic layers. Oxidation or reduction processes of the basic components (ferrocene, fullerene, dendrimer) were investigated by electrochemical techniques, and were in agreement with the structure. Photoinduced electron transfer from ferrocene to fullerene was identified, most likely with a “through space” mechanism.

Domain Compositions and Fullerene Aggregation Govern Charge Photogeneration in Polymer/Fullerene Solar Cells

Abstract: The complex microstructure of organic semiconductor mixtures continues to obscure the connection between the active layer morphology and photovoltaic device performance. For example, the ubiquitous presence of mixed phases in the active layer of polymer/fullerene solar cells creates multiple morphologically distinct interfaces which are capable of exciton dissociation or charge recombination. Here, it is shown that domain compositions and fullerene aggregation can strongly modulate charge photogeneration at ultrafast timescales through studies of a model system, mixtures of a low band-gap polymer, poly[(4,4′-bis(2-ethylhexyl)dithieno[3,2-b:2′,3′-d] germole)-2,6-diyl-alt-(2,1,3-benzothia-diazole)-4,7-diyl], and [6,6]-phenylC 71 -butyric acid methyl ester. Structural characterization using energyfi ltered transmission electron microscopy (EFTEM) and resonant soft X-ray scattering shows similar microstructures even with changes in the overall fi lm composition. Composition maps generated from EFTEM, however, demonstrate that compositions of mixed domains vary signifi cantly with overall fi lm composition. Furthermore, the amount of polymer in the mixed domains is inversely correlated with device performance. Photoinduced absorption studies using ultrafast infrared spectroscopy demonstrate that polaron concentrations are highest when mixed domains contain the least polymer. Grazing-incidence X-ray scattering results show that larger fullerene coherence lengths are correlated to higher polaron yields. Thus, the purity of the mixed domains is critical for effi cient charge photogeneration because purity modulates fullerene aggregation and electron delocalization.

Hydrogen sieving and storage in fullerene intercalated graphite

Abstract: The geometrical properties of recently synthesised C60 intercalated in graphite have been confirmed by density-functional-based computer simulations. The capability of this material to store molecular hydrogen by physisorption is evaluated. While the material can sieve H2 from heavier molecular gases, our free energy calculations indicate that further tuning of the system by reducing the amount of intercalated fullerene cages is necessary to achieve H2 loadings which are interesting for technical applications.