Javier Vela, scientist at the U.S. Department of Energy's Ames Laboratory, believes improvements in computer processors, TV displays and solar cells will come from scientific advancements in the synthesis of low-dimensional nanomaterials.
Ames Laboratory scientists are known for their expertise in the synthesis and manufacturing of materials of different types, according to Vela, who is also an Iowa State University associate professor of chemistry. In many instances, those new materials are made in bulk form, which means micrometers to centimeters in size. Vela's group is working with tiny, nanometer, or one billionth of a meter sized, nanocrystals.
"We're trying to find out what happens with materials when we go to lower particle sizes, will the materials be enhanced or negatively impacted, or will we find properties that weren't expected," Vela said. "Our goal is to broaden the science of low-dimensional nanomaterials."
In an invited paper published in Chemistry of Materials entitled, "Synthetic Development of Low Dimensional Materials", Vela and coauthors Long Men, Miles White, Himashi Andaraarachchi, and Bryan Rosales discussed highlights of some of their most recent work on the synthesis of low dimensional materials.
One of those topics was advancements in the synthesis of germanium-based core-shell nanocrystals. Vela says industry is very interested in semiconducting nanocrystal-based technologies for applications such as solar cells.
Small particle size can affect many things from transport properties (how well a nanocrystal conducts heat and electricity) to optical properties (how strong it interacts with light, absorbs light and emits light). This is especially true in photovoltaic solar cells "Let's say you're using a semiconductor material to make a solar device, there's often different performance when solar cells are made from bulk materials as opposed to when they are made with nanomaterials. Nanomaterials interact with light differently; they absorb it better. That's one way you can manipulate devices and fine tune their performance or power conversion efficiency," said Vela.
Beyond solar cells, Vela says there's tremendous interest in using nanocrystals in quantum dot television and computer displays, optical devices like LEDs (light-emitting diodes), biological imaging, and telecommunications.
He says there are many challenges in this area because depending upon the quality of the nanocrystals used, you can see different emission properties, which can affect the purity of light. "Ultimately the size of the nanocrystals being used can make a huge difference in the cleanliness or crispness of colors in TV and computer displays," said Vela. "Television and computer technology is a multibillion dollar business worldwide, so you can see the potential value our understanding of properties of nanocrystals could bring to these technologies."
In the paper, Vela's group also discussed advancements made in the study of synthesis and spectroscopic characterization of organolead halide perovskites, which Vela says are some of the most promising semiconductors for solar cells because of their low cost and easier processability. He adds photovoltaics made of these materials now reach power conversion efficiencies of greater than 22 percent. Vela's research in this area has focused on mixed-halide perovskites.
He says his group has discovered these materials exhibit interesting chemical and photo physical properties that people hadn't realized before, and now they are trying to better understand the correlation between the structure and chemical composition of perovskites and how they behave in solar cells. "One of our goals is to use what we've learned to help lower the cost of solar cells and produce them more reliably and readily," Vela said.
In addition, Vela's group is studying how to replace lead in traditional organolead halide perovskites with something less toxic, like germanium. "In principle, this is an area that should be much better known, but it's not," said Vela. "When we've been able to substitute germanium for lead, we have been able to produce a lighter perovskite, which he says could positively impact the automotive industry, for example.
"This could have great implications for transportation applications where you don't want a lot of lead because it's so heavy," said Vela. Going forward Vela says his group's focus will be on advancing the science in low-dimensional materials.
"We're not working with well-known materials, but the newest; the most recently discovered," Vela said. "And every time we can advance the science we're one step closer to opportunities for more commercialization, more production, more manufacturing and more jobs in the U.S."
This work was supported by the U.S. Department of Energy's Office of Science.
Ames Laboratory is a U.S. Department of Energy Office of Science national laboratory operated by Iowa State University. Ames Laboratory creates innovative materials, technologies and energy solutions. We use our expertise, unique capabilities and interdisciplinary collaborations to solve global problems.
DOE's Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.
Steve Karsjen | EurekAlert!
New biomaterial could replace plastic laminates, greatly reduce pollution
21.09.2017 | Penn State
Stopping problem ice -- by cracking it
21.09.2017 | Norwegian University of Science and Technology
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
22.09.2017 | Life Sciences
22.09.2017 | Medical Engineering
22.09.2017 | Physics and Astronomy