Category Physics

Interfacial functionalization steps.

An international team has succeeded in considerably increasing the efficiency for direct solar water splitting with a tandem solar cell whose surfaces have been selectively modified. The new record tops the previous 12.4%. Until now, manufacturing of solar hydrogen at the industrial level has failed due to the costs, however. This is because the efficiency of artificial photosynthesis, i.e. the energy content of the hydrogen compared to that of sunlight, has simply been too low to produce hydrogen from the sun economically.

Matthias May at TU Ilmenau and the HZB Institute for Solar Fuels, processed and surveyed about one hundred samples in his excellent doctoral dissertation to achieve this...

University of Vermont scientists have invented a new way to create what they are calling an electron superhighway in an organic semiconductor that promises to allow electrons to flow faster and farther — aiding the hunt for flexible electronics, organic solar cells, and other low-cost alternatives to silicon. To explore these organic materials, UVM graduate students (from left) Naveen Rawat and Lane Manning, and professors Randy Headrick and Madalina Furis, deployed this table-top scanning laser microscope. Their latest finding is reported in the journal Nature Communications — and may, someday not too far off, let you roll up your computer like a piece of paper. Credit: Joshua Brown, UVM

This approach promises to allow electrons to flow faster and farther – aiding the hunt for flexible el...

Bathed in simulated sunlight, this photoelectrolysis cell in the lab of Song Jin, a professor of chemistry at the University of Wisconsin-Madison, splits water into hydrogen and oxygen using a catalyst made of the abundant elements cobalt, phosphorus and sulfur. Credit: David Tenenbaum/University of Wisconsin-Madison

Jin’s research team reports a hydrogen-making catalyst containing phosphorus and sulfur – both common elements – and cobalt, a metal that is 1,000 times cheaper than platinum. This is in answer to the major roadblock to “hydrogen economy”, ie the need for platinum or other expensive noble metals in the water-splitting devices. Noble metals are normally used as they resist oxidation and include many of the precious metals, such as platinum, palladium, iridium and gold.

Catalyst...

This was first deemed impossible. Apps include: novel, energy-efficient electronic devices, particularly integrated circuits. A spin wave is caused by a perturbation of local magnetisation direction in a magnetic material. Such a perturbation is caused by an electron with an opposite spin, relative to the magnetisation. Spin waves transmit these perturbations in the material. This research demonstrates for the first time that it is possible to transmit electric signals in an insulating material.

So far, electrical circuits based on spin waves have not been realised, since it turned out to be impossible to introduce a perturbation in the system large enough to create spin waves...