Solar cells based on perovskites reach high efficiencies: They convert more than 20 percent of the incident light directly into usable power. On their search for underlying physical mechanisms, researchers of the Karlsruhe Institute of Technology (KIT) have now detected strips of nanostructures with alternating directions of polarization in the perovskite layers. These structures might serve as transport paths for charge carriers. This is reported in the Energy & Environmental Science Journal.

The perovskites used by the KIT scientists are metal organic compounds with a special crystal structure and excellent photovoltaic properties. Since their discovery in 2009, perovskite solar cells have experienced a rapid development. Meanwhile, they reach power conversion efficiencies of more than 20 percent. This makes them one of the most promising photovoltaic technologies. Research into perovskite solar cells, however, faces two special challenges: The light-absorbing layers have to be made more robust to environmental impacts and the lead contained therein has to be replaced by environmentally more compatible elements. This requires in-depth understanding of physical mechanisms that enable the high conversion rate of absorbed solar energy into electric power. 

By replacing the phosphor screen in a laser phosphor display (LPD) with a luminescent solar concentrator (LSC), one can harvest energy from ambient light as well as display high-resolution images. "Energy-harvesting laser phosphor display and its design considerations," published recently by SPIE, the international society for optics and photonics, in the Journal of Photonics for Energy, describes the development, processes, and applications of an LPD.

In a proof-of-concept experiment, lead author Ichiro Fujieda and his collegeagues at Ritsumeikan University fabricated a 95 × 95 × 10 mm screen by sandwiching a thin layer of coumarin 6 with two transparent plates. These plates guided the photoluminescent (PL) photons emitted in both directions toward their edge surfaces. After removing the light source in a DMD-based commercial grade projector and feeding a blue laser beam into its optics, the screen generated green images.

In May, a team of Goddard scientists will begin measuring greenhouse gases over the Mid-Atlantic region — an area chosen in part because it encompasses a range of vegetation, climate, and soil types that would influence the exchange of carbon dioxide and methane between the Earth and the atmosphere.

The airborne campaign, called the Carbon Airborne Flux Experiment, or CARAFE, could help scientists better understand the exchange process, also known as flux, and improve computer models that predict Earth’s carbon sinks, natural or artificial areas that absorb carbon dioxide or methane.

Glacier flow at the southern Antarctic Peninsula has increased since the 1990s, but a new study has found the change to be only a third of what was recently reported.

James Thuch Madhier fled South Sudan as a teenager, escaping the ravages of civil war and famine.

Next fall, the U of T undergrad and his social entrepreneurship team will be testing out their solar-powered crop irrigation system on 20 acres of land they've acquired in South Sudan.

It is a common trope in disaster movies: an earthquake strikes, causing the ground to rip open and swallow people and cars whole. The gaping earth might make for cinematic drama, but earthquake scientists have long held that it does not happen.

A UBC-led research team has developed a new global coral bleaching database that could help scientists predict future bleaching events.

By examining the cooling rate of rocks that formed more than 10 miles beneath the Earth’s surface, scientists led by The University of Texas at Austin Jackson School of Geosciences have found that water probably penetrates deep into the crust and upper mantle at mid-ocean spreading zones, the places where new crust is made. The finding adds evidence to one side of a long-standing debate on how magma from the Earth’s mantle cools to form the lower layers of crust.

Nick Dygert, a postdoctoral fellow in the Jackson School’s Department of Geological Sciences, led the research which was published in May in the print edition of Earth and Planetary Science Letters. Collaborators include Peter Kelemen of Colombia University and Yan Liang of Brown University.

Global warming is a concept very well-known to people today, even those who are not particularly invested in such matters. However, this knowledge becomes obsolete very quickly. Take the greenhouse effect. We all have heard about the ??2 emissions and their detrimental effect on our planet. According to the US EPA data, 76% of all greenhouse gas emissions are carbon dioxide, and 16% - methane (??4). However, despite this great differential, methane is actually much more dangerous. Intergovernmental Panel on Climate Change gives a good insight into that. As per their research, the greenhouse activity of methane is 28 times higher than that of carbon dioxide in the timeframe of 100 years and 80 times higher if the next 20 years are taken into account. Moreover, methane concentration in the atmosphere grows exponentially. And the explanation for that may be derived from our distant past.

From atop this grassy mesa in 1967, scientists with the federal Environmental Science Services Agency carefully launched a weather balloon carrying a new instrument that could measure ozone levels from the ground to the very edge of outer space -- and radio the data back to a ground receiver.