Science

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New technique helps probe performance of organic solar cell materials

Bulk heterojunction (BHJ) organic solar cells are fabricated with the polymer semiconductor aligned in the plane of the film to probe charge recombination losses associated with aggregates characterized by varying degrees of local order. 100% uniaxial strain is applied on ductile poly(3-hexylthiophene):phenyl-C61-butyric acid methyl ester (P3HT:PCBM) BHJ films and characterize the resulting morphology with ultraviolet-visible absorption spectroscopy and grazing incidence X-ray diffraction. It is found that the strained films result in strong alignment of the highly ordered polymer aggregates. Polymer aggregates with lower order and amorphous regions also align but with a much broader orientation distribution. The solar cells are then tested under linearly polarized light where the light is selectively absorbed by the appropriately oriented polymer, while maintaining a common local environment for the sweep out of photogenerated charge carriers. Results show that charge collection losses associated with a disordered BHJ film are circumvented, and the internal quantum efficiency is independent of P3HT local aggregate order near the heterojunction interface. Uniquely, this experimental approach allows for selective excitation of distinct morphological features of a conjugated polymer within a single BHJ film, providing insight into the morphological origin of recombination losses.

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In-Plane Alignment in Organic Solar Cells to Probe the Morphological Dependence of Charge Recombination.

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Helicopter Could be 'Scout' for Mars Rovers

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A proposed helicopter could triple the distances that Mars rovers can drive in a Martian day and help pinpoint interesting targets for study.

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Nanotechnology grow light system uses 75% less electricity, grows 33% faster

Our scientist developed a reflective surface coating on our fixtures at the Nano level (atom level) placing atom crystals in strategic patterns to produce unsurpassed brilliance with a spectrum of colors impossible to produce until today.

In simple terms, our scientists developed reflective surfaces by arranging and rearranging crystal atoms to obtain the optimum reflective brilliance, hence our light is the closest to sunlight. This explains the massive brightness our light produces and why plants grow 33% faster with 75% less electricity.

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New Molecular Beam Epitaxy deposition equipment at the ICN2

The new equipment allows the manufacturing of topological insulators, among other materials, and the possibility to study their properties when submitted to different conditions. The installation of the MBE also means a new way of collaboration among ICN2 Groups thanks to the new Severo Ochoa positions.

A new molecular beam epitaxy (MBE) equipment has been installed at the Institut Catalŕ de Nanocičncia i Nanotecnologia (ICN2). This acquisition has been led by ICREA Research Prof. Sergio Valenzuela, Group Leader of the Physics and Engineering of Nanodevices Group, and it has been possible thanks to his European Research Council Starting Grant.

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The path to artificial photosynthesis: HZB researchers describe efficient manganese catalyst capable of converting light to chemical energy

Through their work, Professor Emad Aziz, head of the HZB Institute "Methods for Material Development", Professor Leone Spiccia from Monash University and their teams have taken an important leap forward in understanding photosynthesis - the method green plants use to obtain energy - in artificial systems.

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Artificial catalysts imitate natural photo-synthesis.

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A spoonful of sugar in silver nanoparticles to regulate their toxicity

The use of colloidal silver to treat illnesses has become more popular in recent years, but its ingestion, prohibited in countries like the US, can be harmful to health. Scientists from the Max Planck Institute in Germany have now confirmed that silver nanoparticles are significantly toxic when they penetrate cells, although the number of toxic radicals they generate can vary by coating them with carbohydrates.

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This is a microscope image of a cell with silver nanoparticles with green fluorescence and red-stained nucleus.

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Laser-generated surface structures create extremely water-repellent metals: Super-hydrophobic properties could lead to applications in solar panels, sanitation and as rust-free metals

Scientists at the University of Rochester have used lasers to transform metals into extremely water repellent, or super-hydrophobic, materials without the need for temporary coatings.

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Professor Chunlei Guo has developed a technique that uses lasers to render materials hydrophobic, illustrated in this image of a water droplet bouncing off a treated sample.

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Hydrogels deliver on blood-vessel growth: Rice researchers introduce improved injectable scaffold to promote healing

Rice University scientists have found the balance necessary to aid healing with high-tech hydrogel.

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A microscopic image shows the extensive infiltration of robust blood vessels (red) in a new hydrogel scaffold developed at Rice University to help the healing of internal injuries. The purple cells are pericyte-like cells that surround new endothelial cells, helping to stabilize the vessels. The green cells are circulating through the new vascular system.

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Magnetic Nanosorbents Able to Eliminate Chemical Contaminants

Iranian researchers from Shahid Beheshti University succeeded in the production of a nanosorbent that can separate high percentages of contaminants in natural samples.

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Nanotechnology Used to Produce Ceramic Membrane with High Thermal Stability

Iranian researchers used nanotechnology to produce a new type of ceramic membrane with high thermal stability.

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