Researchers from North Carolina State University and the Chinese Academy of Sciences have created an efficient, semi-printed plastic solar cell without the use of environmentally hazardous halogen solvents. These solar cells can be manufactured at room temperature, which has implications for large-scale commercial production.
Plastic solar cells, or organic photovoltaics, are popular because they are lightweight, flexible, transparent and inexpensive to manufacture, making them useful in multiple applications. Unfortunately, the halogen-containing solvents used in their manufacture are an obstacle to large-scale commercialization. These solvents are key to making sure that the solar cell’s morphology, or structure, maximizes its energy efficiency; however, they are environmentally hazardous. Additionally, the use of these harsh chemicals requires a controlled environment, which adds to production costs.
Long Ye, a postdoctoral research scholar in physics at NC State and lead author of a paper describing the work, wanted to find out if nontoxic solvents could provide equally efficient morphology in the manufacturing process. Ye and his colleagues developed a proof of concept semi-printed plastic solar cell that utilized o-methylanisole (o-MA) as the solvent. O-MA is a commonly used flavoring agent in foods, and is nontoxic to humans.
The researchers used soft X-ray techniques to study the morphology of their solar cell. They found that the o-MA based solar cell had similar morphology, crystalline features and device performance to those produced by halogenated solvents. The solar cell’s overall efficiency rating was around 8.4 percent. Furthermore, their cell could be produced via blade coating at ambient, or room temperature. Blade coating is a process that uses a glass blade to spread a thin layer of the photovoltaic film onto either a rigid or flexible substrate, and the process is compatible with large-scale commercial manufacturing.
“Two of the key requirements for mass producing these solar cells are that the cells can be produced in the open air environment and that the process doesn’t pose health or environmental hazards,” Ye says. “Hopefully this work can help pave the way for printing solar cells in ambient air.”
Learn more: Food Additive Key to Environmentally Friendly, Efficient, Plastic Solar Cells
Collectively known as the “Two Academies (二院)” along with the Chinese Academy of Engineering, it is an institution of the State Council of China, functioning as the national scientific thinktank and academic governing body, providing advisory and appraisal services on issues stemming from the national economy, social development, and science and technology progress. It is headquartered in Beijing, with branch institutes all over mainland China. It has also created hundreds of commercial enterprises, with Lenovo being one of the most famous.
The Chinese Academy has its roots from Academia Sinica,founded in 1928 by the Guomindang Nationalist Government. After Communist Party in control of mainland China, Academia Sinica was renamed as Chinese Academy of Sciences.
Chinese Academy of Sciences research articles from Innovation Toronto
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Approach tackles most commonly used synthetic plastic
A new way of recycling millions of tons of plastic garbage into liquid fuel has been devised by researchers from the University of California, Irvine and the Shanghai Institute of Organic Chemistry (SIOC) in China.
“Synthetic plastics are a fundamental part of modern life, but our use of them in large volume has created serious environmental problems,” said UCI chemist Zhibin Guan. “Our goal through this research was to address the issue of plastic pollution as well as achieving a beneficial outcome of creating a new source of liquid fuel.”
Guan and Zheng Huang, his collaborator at SIOC, together with their colleagues have figured out how to break down the strong bonds of polyethylene, the most common commercially available form of plastic. Their innovative technique centers on the use of alkanes, specific types of hydrocarbon molecules, to scramble and separate polymer molecules into other useful compounds. The team’s findings were published recently in Science Advances.
A simple chemical conversion could be another step toward making cheap, efficient and stable perovskite solar cells.
Thin films of crystalline materials called perovskites provide a promising new way of making inexpensive and efficient solar cells. Now, an international team of researchers has shown a way of flipping a chemical switch that converts one type of perovskite into another — a type that has better thermal stability and is a better light absorber.
The study, by researchers from Brown University, the National Renewable Energy Laboratory (NREL) and the Chinese Academy of Sciences’ Qingdao Institute of Bioenergy and Bioprocess Technology published in the Journal of the American Chemical Society, could be one more step toward bringing perovskite solar cells to the mass market.
“We’ve demonstrated a new procedure for making solar cells that can be more stable at moderate temperatures than the perovskite solar cells that most people are making currently,” said Nitin Padture, professor in Brown’s School of Engineering, director of Brown’s Institute for Molecular and Nanoscale Innovation, and the senior co-author of the new paper. “The technique is simple and has the potential to be scaled up, which overcomes a real bottleneck in perovskite research at the moment.”
In a doughnut-shaped chamber in eastern China, scientists have been able to produce hydrogen gas more than three times hotter than the core of the Sun using nuclear fusion – and maintain this temperature for 102 seconds.
The breakthrough puts China one step ahead in the global race to harness a new, artificial kind of solar energy for clean and unlimited energy, the researchers claim. This has become a pressing concern as more of the earth’s natural reserves are rapidly depleting.
The experiment was conducted last week on a magnetic fusion reactor at the Institute of Physical Science in Hefei, capital of Jiangsu province, according to a statement on the institute’s website on Wednesday.
The reactor, officially known as the Experimental Advanced Superconducting Tokamak (EAST), was able to heat a hydrogen gas – a hot ionised gas called a plasma – to about 50 million Kelvins (49.999 million degrees Celsius). The interior of our sun is calculated to be around 15 million Kelvins.
According to this thermodynamic scale, absolute zero occurs at zero degrees (equivalent to minus 273.15 degrees Celsius), a point at which all molecular movement stops.
The temperature reached in Hefei was at the other end of the scale, and roughly the same as a mid-sized thermonuclear explosion. The goal of the experiment was to approximate the nuclear fusion conditions that occur deep inside the sun.
Although at least one other experiment in the last decade claims to have produced a hotter temperatures than this, it has never been duplicated and was unable to match the endurance – over one and a half minutes – of the Chinese test.
Meanwhile, physicists in Japan and Europe have been able to reach the same temperature as the Chinese team, but not for longer than a minute due to concerns of provoking a reactor meltdown.
The EAST was invented by Soviet scientists to control nuclear fusion for power generation.
As a tokamak device, it uses a powerful magnetic field to confine plasma in the shape of a torus – imagine a large spinning doughnut -for safety reasons due to the phenomenally high temperatures being generated. The atoms are effectively held floating in place by superconducting magnets.
But controlling hydrogen gas in such a hot and volatile state is a formidable challenge, and one that most of the tokomak devices built over the last 60 years have not been able to sustain for more than 20 seconds.
The scientists in Hefei worked “day and night” to achieve the record level of endurance, according to the institute, which serves as a subsidiary of the Chinese Academy of Sciences.
China is well-known for investing in technological advancements – from space explorations to military warfare. In its latest groundbreaking invention, soldiers are now in possession of Star Wars-like laser guns.
This laser gun could soon have the ability to attack heat-seeking sensors on missiles, satellites and other warfare using breakthrough portable-laser technology. When the laser comes in contact with infrared missiles, their sensors become disabled, rendering them useless.
A team of Chinese researchers, led by Professor Zhi-Yuan Li of the Chinese Academy of Sciences’ Institute of Physics, decreased the size and mechanism that produces high-frequency laser down using a portable device the size of a suitcase. These can be easily mounted on tanks, aircrafts and can be used by the soldiers themselves.
“This is a groundbreaking achievement,” said a professor at Tsinghua University, Beijing who requested anonymity in the issue.
“Nobody has generated a laser at such a high frequency on a single piece of crystal before. Their technology will significantly simplify the process of ultrafast laser production and reduce the size of relevant devices,” added the anonymous professor.
Laser Technology Is Banned To Use In Warfare
The Protocol on Blinding Laser Weapons which was updated on October 1995, an international convention and treaty, bans the use of lasers and blinding weapons used against enemies. It states that it is prohibited to employ laser weapons specifically designed to cause permanent blindness to unenhanced vision like the naked eye.
Though China aims to use its newest laser guns on optical and thermal sensors on vehicles, drones, robots and aircraft, the possession of this kind of technology is still fair game. Aside from damaging enemy targets, it can also pick up encrypted communications and detect stealth aircraft.
Breakthrough could help address growing demand for the staple that already provides a fifth of global caloric intake.
An international team of scientists has identified a gene that can prevent some of the most significant wheat diseases—creating the potential to save more than a billion dollars in lost production in Australia each year.
Estimates put potential losses from wheat rust diseases in Australia alone at more than one-and-a-half billion dollars each year.Associate Professor Harbans Bariana
The findings should have wide-reaching ramifications, with wheat already providing a fifth of global caloric intake and set to spike in the next 50 years.
A gene that can prevent some of the most important wheat diseases has been identified—creating the potential to save more than a billion dollars in lost production in Australia each year.
In a global collaboration including the University of Sydney’s Plant Breeding Institute (PBI), the CSIRO, CIMMYT (Mexico), University of Newcastle, Chinese Academy of Sciences and the Norwegian University of Life Sciences, the gene Lr67 has been identified as providing resistance to three of the most important wheat rust diseases, along with powdery mildew, a significant disease in Norway.
The findings, published today in Nature Genetics, should have wide-reaching ramifications, with wheat already providing a fifth of global caloric intake and set to spike in the next 50 years.
Rice University catalyst holds promise for clean, inexpensive hydrogen production
Graphene doped with nitrogen and augmented with cobalt atoms has proven to be an effective, durable catalyst for the production of hydrogen from water, according to scientists at Rice University.
The Rice lab of chemist James Tour and colleagues at the Chinese Academy of Sciences, the University of Texas at San Antonio and the University of Houston have reported the development of a robust, solid-state catalyst that shows promise to replace expensive platinum for hydrogen generation.
Nanotechnology offers new approach to increasing storage ability of dielectric capacitors
For Back to the Future fans, this week marked a milestone that took three decades to reach.
Oct. 21, 2015, was the day that Doc Brown and Marty McFly landed in the future in their DeLorean, with time travel made possible by a “flux capacitor.”
While the flux capacitor still conjures sci-fi images, capacitors are now key components of portable electronics, computing systems, and electric vehicles.
In contrast to batteries, which offer high storage capacity but slow delivery of energy, capacitors provide fast delivery but poor storage capacity.
A great deal of effort has been devoted to improving this feature — known as energy density — of dielectric capacitors, which comprise an insulating material sandwiched between two conducting metal plates.
The work is reported in a paper, “Dielectric Capacitors with Three-Dimensional Nanoscale Interdigital Electrodes for Energy Storage,” published in Science Advances, the first open-access, online-only journal of AAAS.
“With our approach, we achieved an energy density of about two watts per kilogram, which is significantly higher than that of other dielectric capacitor structures reported in the literature,” says Bingqing Wei, professor of mechanical engineering at UD.
“To our knowledge, this is the first time that 3D nanoscale interdigital electrodes have been realized in practice,” he adds. “With their high surface area relative to their size, carbon nanotubes embedded in uniquely designed and structured 3D architectures have enabled us to address the low ability of dielectric capacitors to store energy.”
Read more: Capacitor breakthrough
Australian and Chinese scientists have made significant progress in determining what causes soil acidification – a discovery that could assist in turning back the clock on degraded croplands.
James Cook University’s Associate Professor Paul Nelson said the Chinese Academy of Sciences sought out the Australian researchers because of work they had done in Australia and Papua New Guinea on the relationship between soil pH levels and the management practices that cause acidification.
Building on the JCU work, scientists examined a massive 3600 km transect of land in China, stretching from the country’s sub-arctic north to its central deserts. The work yielded a new advance that describes the mechanisms involved in soils becoming acidified.
Dr Nelson said soil degradation is a critical problem confronting humanity, particularly in parts of the world such as the tropics where land use pressure is increasing and the climate is changing. “We can now quantify the effect of, for instance, shutting down a factory that contributes to the production of acid rain,” he said.
Dr Nelson said the research found different drivers of soil acidification processes in different types of soil across northern China. “This information is vital for designing strategies that prevent or reverse soil acidification and to help land managers tailor their practices to maintain or improve soil quality,” he said.
The Patron of Soil Science Australia, former Australian Ambassador to the United Nations and for the Environment, The Honourable Penny Wensley AC, welcomed news of the advance.
“With 2015 designated by the United Nations as the International Year of Soils, this is a very important year for soil scientists around the world. We need to promote greater awareness of the importance of soils and soil health and the role soil science has to play in addressing national and global challenges.”
In the context of the International Year of Soils, onHPenny Wensley said: “We want to encourage greater cooperation and exchanges between soil scientists, to accelerate progress in research and achieve outcomes that will deliver practical benefits to farmers and land managers, working in diverse environments.
“This research project, drawing on the shared expertise of soil scientists from Australia’s James Cook University and the Chinese Academy of Sciences, is an exciting illustration of what can be achieved through greater collaboration,” she said.
Read more: Work on barren soil may bear fruit
The world’s deserts may be storing some of the climate-changing carbon dioxide emitted by human activities, a new study suggests. Massive aquifers underneath deserts could hold more carbon than all the plants on land, according to the new research.
Humans add carbon dioxide to the atmosphere through fossil fuel combustion and deforestation. About 40 percent of this carbon stays in the atmosphere and roughly 30 percent enters the ocean, according to the University Corporation for Atmospheric Research. Scientists thought the remaining carbon was taken up by plants on land, but measurements show plants don’t absorb all of the leftover carbon. Scientists have been searching for a place on land where the additional carbon is being stored—the so-called “missing carbon sink.”
The new study suggests some of this carbon may be disappearing underneath the world’s deserts – a process exacerbated by irrigation. Scientists examining the flow of water through a Chinese desert found that carbon from the atmosphere is being absorbed by crops, released into the soil and transported underground in groundwater—a process that picked up when farming entered the region 2,000 years ago.
Underground aquifers store the dissolved carbon deep below the desert where it can’t escape back to the atmosphere, according to the new study.
The new study estimates that because of agriculture roughly 14 times more carbon than previously thought could be entering these underground desert aquifers every year. These underground pools that taken together cover an area the size of North America may account for at least a portion of the “missing carbon sink” for which scientists have been searching.
“The carbon is stored in these geological structures covered by thick layers of sand, and it may never return to the atmosphere,” said Yan Li, a desert biogeochemist with the Chinese Academy of Sciences in Urumqi, Xinjiang, and lead author of the study accepted for publication in Geophysical Research Letters, a journal of the American Geophysical Union. “It is basically a one-way trip.”
Knowing the locations of carbon sinks could improve models used to predict future climate change and enhance calculations of the Earth’s carbon budget, or the amount of fossil fuels humans can burn without causing major changes in the Earth’s temperature, according to the study’s authors.
Although there are most likely many missing carbon sinks around the world, desert aquifers could be important ones, said Michael Allen, a soil ecologist from the Center for Conservation Biology at the University of California-Riverside who was not an author on the new study.
If farmers and water managers understand the role heavily-irrigated inland deserts play in storing the world’s carbon, they may be able to alter how much carbon enters these underground reserves, he said.
“This means [managers] can take practical steps that could play a role in addressing carbon budgets,” said Allen.
Examining desert water
To find out where deserts tucked away the extra carbon, Li and his colleagues analyzed water samples from the Tarim Basin, a Venezuela-sized valley in China’s Xinjiang region. Water draining from rivers in the surrounding mountains support farms that edge the desert in the center of the basin.
The researchers measured the amount of carbon in each water sample and calculated the age of the carbon to figure out how long the water had been in the ground.
The study shows the amount of carbon dioxide dissolved in the water doubles as it filters through irrigated fields. The scientists suggest carbon dioxide in the air is taken up by the desert crops. Some of this carbon is released into the soil through the plant’s roots. At the same time, microbes also add carbon dioxide to the soil when they break down sugars in the dirt. In a dry desert, this gas would work its way out of the soil into the air. But on arid farms, the carbon dioxide emitted by the roots and microbes is picked up by irrigation water, according to the new study.
In these dry regions, where water is scarce, farmers over-irrigate their land to protect their crops from salts that are left behind when water used for farming evaporates. Over-irrigating washes these salts, along with carbon dioxide that is dissolved in the water, deeper into the earth, according to the new study.
Although this process of carbon burial occurs naturally, the scientists estimate that the amount of carbon disappearing under the Tarim Desert each year is almost 12 times higher because of agriculture. They found that the amount of carbon entering the desert aquifer in the Tarim Desert jumped around the time the Silk Road, which opened the region to farming, begin to flourish.
After the carbon-rich water flows down into the aquifer near the farms and rivers, it moves sideways toward the middle of the desert, a process that takes roughly 10,000 years.
Any carbon dissolved in the water stays underground as it makes its way through the aquifer to the center of the desert, where it remains for thousands of years, according to the new study.