Category Physics

Rows of photovoltaic cells are shown atop a building on the Georgia Institute of Technology campus in Atlanta.
Credit: John Toon, Georgia Tech

A team of semiconductor researchers based in France has used a boron nitride separation layer to grow indium gallium nitride (InGaN) solar cells that were then lifted off their original sapphire substrate and placed onto a glass substrate.

By combining the InGaN cells with photovoltaic (PV) cells made from materials such as silicon or gallium arsenide, the new lift-off technique could facilitate fabrication of higher efficiency hybrid PV devices able to capture a broader spectrum of light. Such hybrid structures could theoretically boost solar cell efficiency as high as 30% for an InGaN/Si tandem device.

The technique is the third major application f...

A perovskite-CIGS solar cell developed by UCLA Samueli researchers converts 22.4 percent of incoming energy from the sun, a record for this type of cell.
Credit: UCLA Samueli Engineering

Materials scientists from the UCLA Samueli School of Engineering have developed a highly efficient thin-film solar cell that generates more energy from sunlight than typical solar panels, thanks to its double-layer design. The device is made by spraying a thin layer of perovskite – an inexpensive compound of lead and iodine that has been shown to be very efficient at capturing energy from sunlight – onto a commercially available solar cell. The solar cell that forms the bottom layer of the device is made of a compound of copper, indium, gallium and selenide, or CIGS.

The team’s new cell converts 22...

Different configurations change the adhesive effect of the silicone material, whose surface has been given a mushroom-like structure. The adhesion is best when bent concave (right).
Credit: © Emre Kizilkan

A research team has succeeded in boosting the adhesive effect of a silicone material significantly inspired by the structure of beetle feet. In addition, they found out that the adhesiveness of the structured material changes drastically, if it is bent to varying degrees. Their results could be interesting for the development of tiny robots and gripping devices.

Geckos, spiders and beetles have shown us how to do it: thanks to special adhesive elements on their feet, they can easily run along ceilings or walls...

Schematic illustration of single-atom catalyst anchored on porous carbon.
Credit: WSU

Researchers at Washington State University have developed a new way to make low-cost, single-atom catalysts for fuel cells – an advance that could make important clean energy technology more economically viable. Hydrogen fuel cells are critical for the clean energy economy as they are more than two times as efficient at creating electricity than polluting combustion engines. Their only waste product is water.

However, the high price of the platinum-based catalysts that are used for the chemical reaction in fuel cells significantly hinders their commercialization. Instead of the rare platinum, researchers would like to use nonprecious metals, such as iron or cobalt...