Two solar farms in Minnesota were built on retired agricultural land, and instead of the gravel or mown turf that usually goes under panels, the ground was seeded with native wildflowers and prairie grasses. Researchers from Argonne National Laboratory came back to the same test plots for five years and counted what flew and crawled past them.
A research team led by Taeyeon Kim, a professor in the Department of Chemistry at Sungkyunkwan University, in collaboration with a team from Yonsei University, has identified a new principle that controls charge separation, a phenomenon that plays a central role in both plants’ generation of electrical energy (photosynthesis) and next-generation molecular semiconductor devices.
The findings were published in Nature Communications.
When plants absorb sunlight to generate energy, they rapidly separate and transfer charge within their internal structures. Inspired by this process, the scientific community has long sought to develop next-generation energy devices such as artificial photosynthesis systems and organic solar cells. Molecular aggregate structures formed by densely stacked “perylene bisimide (PBI),” an organic semiconductor molecule known for its excellent electron-accepting properties, have drawn particular research attention. However, the complex environment created by tightly clustered molecules has made it difficult to precisely determine how the surrounding environment alone affects charge transfer.
A biomimetic nanoreactor combines cellular design principles to produce hydrogen peroxide efficiently under visible light.
Inside a hollow nanoscale structure, researchers have recreated two strategies that living cells use to control chemical reactions. The resulting CdS@polydopamine nanoreactor offers a synthetic way to reproduce some of the organization and efficiency found in biological systems.
The work was published in the Journal of the American Chemical Society. Can Li of the Dalian Institute of Chemical Physics (DICP), part of the Chinese Academy of Sciences (CAS), led the research with Jian Liu’s group at Inner Mongolia University.
Many of today’s electronic devices—from the semiconductors in your cell phone to the photovoltaic cells in your solar panels—are built on thin-film substrates. The thin film is an electrically conductive material, while the substrate is an inert material. Or is it?
Physicists and materials scientists have long assumed substrates do not react to electrical stimuli, but new research from the University of California San Diego and a team of collaborators has shown that substrates are not inert after all. The discovery has the potential to help engineers build the dense, three-dimensional, brain-inspired computer chips needed for more energy-efficient computing. This work appears in Science.
The research began four years ago in UC San Diego Associate Professor of Physics Alex Frañó’s lab. Frañó is a principal investigator and assistant director at the Quantum Materials for Energy-Efficient Neuromorphic Computing (Q-MEEN-C), one of the U.S. Department of Energy’s Energy Frontier Research Centers. One of the goals of Q-MEEN-C is to develop quantum materials that can be used in neuromorphic, or “brain-like,” computing.
Semi-transparent solar cells that could be added to windows to efficiently harvest energy from indoor light as well as the sun have been developed by an international team led by UCL researchers.
The technology, described in a paper in Advanced Energy Materials, could help turn buildings into power generators at night and on cloudy days, as well as in sunshine.
The researchers engineered solar windows that let in 30% of sunlight—ordinary glass might let in 80% or 90%—while generating a record amount of energy from indoor light and efficiently harvesting energy from sunshine.
A newly developed material for the electron contact improves the efficiency of single perovskite solar cells and perovskite/silicon tandem solar cells. The new material is based on a carborane molecule. It offers several advantages over the standard material C60, as shown by the study led by Steve Albrecht’s team. The new material has since been patented and is already commercially available.
Perovskite solar cells are not only exceptionally inexpensive to manufacture but also achieve high efficiency levels. Single-junction perovskite devices can already convert more than 27% of sunlight into electrical energy, while perovskite-silicon tandem cells have achieved efficiencies of more than 35%. Until now, a layer of so-called “football molecules” (C60) has been used to transport electrons away. However, a significant proportion of the charge carriers are lost at the interface between the C60 layer and the perovskite absorber. Furthermore, C60 materials are relatively expensive and tend to delaminate over time, compromising the cell’s stability.
In the future, iron might be used as a chemical energy storage material, making large quantities of renewable energy available in the long term. Iron powder is combusted in a cyclic process that is carbon neutral and then reconverted to its original state using energy input. Scientists at Karlsruhe Institute of Technology (KIT) were the first to conduct an extensive study to evaluate the potential of this technology for power generation. Their results show that iron, while not superseding hydrogen, may usefully complement it in a climate-neutral energy system. The findings have been published in Chem Circularity.
Be it for wind energy from coastal regions or for solar power from desert areas, iron could serve as a transportable energy carrier in the future to make these renewable energy sources usable worldwide. “This works in a cycle that emits no carbon dioxide or environmentally harmful substances,” said Julia Schuler from KIT’s Institute for Industrial Production (IIP). For power generation, iron powder is combusted, producing iron oxide, i.e. rust. Using hydrogen from renewable sources, it is reduced to iron again in a process that removes the oxygen it contains. The iron powder can then be reused.
“When burned, iron powder behaves very much like coal. We wanted to find out whether it was possible to repurpose existing coal power plants to iron-firing,” said Schuler. She believes that modifications are primarily necessary in the heat generator; other components, such as the steam cycle, turbines, generator and power grid connection, could continue to be used.
Quantum materials, materials exhibiting physical behavior governed by the laws of quantum mechanics, have proved promising for the development of numerous advanced technologies, including quantum technologies, memory devices and solar panels. In some of these materials, electrons can collectively arrange themselves in unusual patterns, giving rise to states that cannot be explained by classical physics theories.
For more than two decades, theoretical physicists have predicted the existence of a loop current order in some quantum materials. This is a state characterized by tiny electrical currents circulating around microscopic loops inside a crystal, which would produce no measurable electric current flowing through a material.
These current loops were predicted to emerge when electrons spontaneously organize themselves into a less symmetrical pattern than the crystal itself, even if atoms remain in similar positions. While this phenomenon was widely studied and described by theorists in the past, it has so far proved difficult to observe experimentally.
A Berlin-based team from HZB and Center for the Science of Materials Berlin (CSMB) at Humboldt-Universität zu Berlin has set a new record for a tandem solar cell. Using a combination of a CIGS semiconductor layer and perovskite, along with several optimized intermediate layers, the team converted 25.5% of sunlight into electrical energy. The previous record for this combination of materials and this size cell had stood at 24.6%.
The new record has been certified and is visible in the Solar Cell Efficiency Tables (the “Green Tables”) published in the journal Joule, which serve as the definitive ledger for the global photovoltaic community. To be included in this special “record table,” not only is high efficiency required, but also an area of more than 1 cm2. The well-known NLR table (formerly NREL), by contrast, lists only the maximum efficiency per technology, even if the cell has an area of 0.001 cm2.