The scientists, including Penn State faculty Nelson Dzade, reported in the journal Nature Energy their new method for creating more durable perovskite solar cells that still achieve a high efficiency of 21.59% conversion of sunlight to electricity.

Perovskites are promising solar technology because the cells can be manufactured at room temperature using less energy than traditional silicon materials, making them more affordable and more sustainable to produce, according to the Dzade, assistant professor of energy and mineral engineering in the John and Willie Leone Family Department of Energy and Mineral Engineering and co-author of the study. But the leading candidates used to make these devices, hybrid organic-inorganic metal halides, contain organic components that are susceptible to moisture, oxygen and heat, and exposure to real-world conditions can lead to rapid performance degradation, the scientists said.

One solution involves turning instead to all-inorganic perovskite materials like cesium lead iodide, which has good electrical properties and a superior tolerance to environmental factors. However, this material is polymorphic, meaning it has multiple phases with different crystalline structures. Two of the photoactive phases are good for solar cells, but they can easily convert to an undesirable non-photoactive phase at room temperature, which introduces defects and degrades the efficiency of the solar cell, the scientists said.

The scientists combined the two photoactive polymorphs of cesium lead iodide to form a phase-heterojunction — which can suppress the transformation to the undesirable phase, the scientists said. Heterojunctions are formed by stacking different semiconductor materials, like layers in a solar cell, with dissimilar optoelectronic properties. These junctions in solar devices can be tailored to help absorb more energy from the sun and convert it into electricity more efficiently.

“The beautiful thing about this work is that it shows the fabrication of phase heterojunction solar cells by utilizing two polymorphs of the same material is the way to go,” Dzade said. “It improves material stability and prevents interconversion between the two phases. The formation of a coherent interface between the two phases allows electrons to flow easily across the device, leading to enhanced power conversion efficiency. That is what we demonstrated in this piece of work.”

The researchers fabricated a device that achieved a 21.59% power conversion efficiency, among the highest reported for this type of approach, and excellent stability. The devices maintained more than 90% of the initial efficiency after 200?hours of storage under ambient conditions, Dzade said.

“When scaled from a laboratory to a real-world solar module, our design exhibited a power conversion efficiency of 18.43% for a solar cell area of more than 7 square inches (18.08 centimeters squared),” Dzade said. “These initial results highlight the potential of our approach for developing ultra-large perovskite solar cell modules and reliably assessing their stability.”

Dzade modeled the structure and electronic properties of the heterojunction at the atomic scale and found that bringing the two photoactive phases together created a stable and coherent interface structure, which promotes efficient charge separation and transfer — desirable properties for achieving high efficiency solar devices.

Dzade’s colleagues at Chonnam University in South Korea developed the unique dual deposition method for fabricating the device — depositing one phase with a hot-air technique and the other with triple-source thermal evaporation. Adding small amounts of molecular and organic additives during the deposition process further improved the electrical properties, efficiency and stability of the device, said Sawanta S. Mali, a research professor at Chonnam University in South Korea and lead author on the paper.

“We believe the dual deposition technique we developed in this work will have important implications for fabricating highly efficient and stable perovskite solar cells moving forward,” said Nelson Dzade, assistant professor of energy and mineral engineering in the John and Willie Leone Family Department of Energy and Mineral Engineering and co-author of the study.

The researchers said the dual deposition technique could pave the way for the development of additional solar cells based on all inorganic perovskites or other halide perovskite compositions. In addition to extending the technique to different compositions, future work will involve making the current phase-heterojunction cells more durable in real-world conditions and scaling them to the size of traditional solar panels, the researchers said.

“With this approach, we believe it should be possible in the near future to shoot the efficiency of this material past 25%,” Dzade said. “And once we do that, commercialization becomes very close.”

Also contributing were Chang Kook Hong, professor, and Jyoti Patil, research professor, at Chonnam National University, South Korea; Yu-Wu Zhong, professor, and Jiang-Yang Shao, researcher, at the Institute of Chemistry, Chinese Academy of Sciences; and Sachin Rondiya, assistant professor, Indian Institute of Science.

The National Research Foundation of Korea supported this work. Computer simulations were performed on the Roar Supercomputer in the Institute for Computational and Data Sciences at Penn State.

The first study of its kind followed a satellite over six years, observing how the panels generated power and weathered solar radiation over 30,000 orbits.

The findings could pave the way for commercially viable solar farms in space.

Professor Craig Underwood, Emeritus Professor of Spacecraft Engineering at the Surrey Space Centre at the University of Surrey, said:

“We are very pleased that a mission designed to last one year is still working after six. These detailed data show the panels have resisted radiation and their thin-film structure has not deteriorated in the harsh thermal and vacuum conditions of space.

“This ultra-low mass solar cell technology could lead to large, low-cost solar power stations deployed in space, bringing clean energy back to Earth — and now we have the first evidence that the technology works reliably in orbit.”

Researchers from the University of Swansea’s Centre for Solar Energy Research developed new solar cells from cadmium telluride. The panels cover a larger area, are more lightweight, and provide far greater power than current technology — as well as being relatively cheap to manufacture.

Scientists from the University of Surrey designed instruments that measured their performance in orbit. The satellite itself was designed and built at the Surrey Space Centre in partnership with a team of trainee engineers from the Algerian Space Agency (ASAL).

Although the cells’ power output became less efficient over time, researchers believe their findings prove that solar power satellites work and could be commercially viable.

Dr Dan Lamb from the University of Swansea said:

“The successful flight test of this novel thin film solar cell payload has leveraged funding opportunities to further develop this technology.”

“Large area solar arrays for space applications are a rapidly expanding market and demonstrations such as this help to build on the UK’s world class reputations for space technology.”

Lithium ion batteries (LIB) are the most commonly used type of battery in consumer electronics and electric vehicles. Lithium cobalt oxide (LiCoO₂) is the compound used for the cathode in LIB for handheld electronics. Traditionally, the synthesis of this compound requires temperatures over 800°C and takes 10 to 20 hours to complete.

A team of researchers at Hokkaido University and Kobe University, led by Professor Masaki Matsui at Hokkaido University’s Faculty of Science, have developed a new method to synthesize lithium cobalt oxide at temperatures as low as 300°C and durations as short as 30 minutes. Their findings were published in the journal Inorganic Chemistry.

“Lithium cobalt oxide can typically be synthesized in two forms,” Matsui explains. “One form is layered rocksalt structure, called the high-temperature phase, and the other form is spinel-framework structure, called the low-temperature phase. The layered LiCoO₂ is used in Li-ion batteries.”

Using cobalt hydroxide and lithium hydroxide as starting materials, with sodium or potassium hydroxide as an additive, the team conducted a series of high-precision experiments under varying conditions to synthesize layered LiCoO₂ crystals. The process was called the “hydroflux process.” They were also able to determine the reaction pathway that led to the formation of the layered crystals.

“By understanding the reaction pathway, we were able to identify the factors that promoted the crystal growth of layered LiCoO₂,” Matsui said. “Specifically, the presence of water molecules in the starting materials significantly improved crystallinity of the end product.”

The team also measured the electrochemical properties of the layered LiCoO₂, showing that they were only marginally inferior to that of commercially available LiCoO₂ synthesized by the traditional high temperature method.

“This work is the first experimental demonstration of the thermochemical stability of layered LiCoO₂ at low temperatures under ambient pressure,” concludes Matsui. “Our development of this hydroflux process will enable energy saving measures in various ceramic production processes. Our immediate next steps will be the improvement of the hydroflux process based on our understanding of the reaction pathway.”

Antimicrobial resistance occurs when bacteria, viruses, fungi and parasites change over time and no longer respond to the medicines and chemicals we use to kill them. These ‘superbugs’ make infections harder to treat and increase the risk of disease spread, severe illness and death.

Without significant intervention, global annual deaths involving antimicrobial resistance are estimated to reach 10 million by 2050, with low and middle-income countries bearing the highest burden.

The new study, Genomic surveillance for antimicrobial resistance — a One Health perspective, published in Nature Reviews Genetics, highlights the need for a multifaceted ‘One Health’ approach to the surveillance of antimicrobial resistance in the environment.

The research was led by Distinguished Professor Steven Djordjevic from the Australian Institute for Microbiology and Infection at the University of Technology Sydney, together with researchers from the University of Melbourne and the University of South Australia.

“Antimicrobial resistance is a complex and global threat requiring large-scale, co-ordinated and cross-disciplinary collaboration to tackle,” said Professor Djordjevic.

“Understanding the evolution, emergence and spread of antimicrobial resistance within and between humans, animals, plants and natural environments is critical in mitigating the colossal impacts associated with this phenomenon.”

The use of genomic tracing during the Covid-19 pandemic has provided insight into the potential of genomic technologies to monitor the development and spread of antimicrobial genes and mutations.

“Antimicrobial resistance can occur when microorganisms acquire genetic information, either by mutation, recombination or transfer of antibiotic resistance genes from the bacterial gene pool,” said Professor Erica Donner from the University of South Australia.

“Genomic technologies, combined with AI and machine learning, are powerful platforms for determining resistance trends. They can identify instances where microbes and their genetic material move between different environments, evaluating the impact of intervention strategies.

“The evolution of antimicrobial resistance is a complex process that includes the overuse and misuse of antibiotics, metals and disinfectants in medicine and agriculture, and widely varying standards of water, sanitation and hygiene.”

The paper is a call to action for policymakers, highlighting the need to establish national genomic surveillance programs spanning human health, animal health, agriculture, food and environmental management sectors and to share data at both a national and international level.

“Utilising the technology of microbial genomics in the context of effective cross-sectoral data integration will enhance the understanding of antimicrobial resistance emergence and spread within and across these sectors and identify targeted interventions” said Professor Ben Howden from the University of Melbourne.

The researchers provide practical recommendations to implement genomics-enabled surveillance and mitigation strategies and underscore the need for equitable solutions that allow integration of partners from lower- and middle-income countries.

The recommendations include:

• Establishing a national One Health antimicrobial resistance surveillance programme incorporating genomics
• Increase antimicrobial resistance awareness and education and foster collaboration
• Enhancing laboratory capacity in lower and middle-income countries
• Encouraging research and innovation
• Strengthening regulation and oversight in agriculture
• Improving antibiotic stewardship

“The evolutionary nature of antimicrobial resistance makes it a constantly changing and evolving threat. There is no easy solution, but ongoing genomic surveillance can help us better understand and mitigate this global health challenge,” said Professor Djordjevic.

The eclipse was partially visible to much of the continental U.S. for several hours that Saturday, though the full “ring of fire” effect was only visible for less than five minutes, and only for those within its 125-mile-wide path of annularity.

However, the new observations of the radio Sun’s eclipse — much longer in duration than the partial eclipse recently experienced by millions on Earth due to the extended solar corona as seen at radio wavelengths — have yielded stunning images of the eclipse’s ring lasting for over an hour.

Researchers used the newly commissioned Owens Valley Radio Observatory Long Wavelength Array (OVRO-LWA) in the Owens Valley Radio Observatory, CA to make their breakthrough observation of radio waves emanating from the Sun’s extended corona, as the moon passed between Earth and its nearest star.

“To finally see a ‘ring of fire’ eclipse this way was spectacular … we haven’t seen this quality of radio imaging of the Sun before.” said Dale Gary, NJIT-CSTR distinguished professor of physics and co-investigator on the OVRO-LWA project, which is funded by the National Science Foundation.

“We normally cannot see the corona from the ground except during a total eclipse, but we can now see it all the time with OVRO-LWA. This eclipse makes it that much more dramatic.”

“From our observatory site in California we were not in the belt to see the annular eclipse, yet we’ve been able to ‘see’ it all clearly unfold in radio, which reveals a much larger solar disk than its visible counterpart thanks to its sensitivity to the extended solar corona,” said Bin Chen, NJIT-CSTR associate professor of physics who led the data reduction and processing together with NJIT researchers Surajit Mondal and Sijie Yu.

“Science-wise, this is a unique opportunity to study the Sun’s extended corona with the highest resolution possible at these wavelengths, taking advantage of the moon’s limb as a moving ‘knife edge’ to increase the effective angular resolution,” said Chen.

OVRO-LWA, a multi-institutional project directed by Gregg Hallinan at California Institute of Technology, uses a set of 352 antennas to sample thousands of radio wavelengths between ~20-88 MHz.

For solar science, it offers the highest-quality images yet of the radio Sun in this wavelength regime, which is roughly two times larger than the visible solar disk.

“Documenting this spectacular event was a great opportunity to announce the successful operation of OVRO-LWA as a new radio facility to study the Sun and many other objects including exoplanets, cosmic-rays, the early universe, and more,” said Hallinan.

While the next annular solar eclipse is expected to be visible from South America in October 2024, those in the U.S. will need to wait until June 2039 to view the next ‘ring of fire’ eclipse on home soil. However, a total eclipse visible across the central U.S. will occur sooner, next April 8.

However, the team say the recent eclipse event is an outstanding example of the first observations of the Sun with the instrument. With the new capabilities OVRO-LWA offers, exciting science is expected in the near future — particularly as solar activity of the current 11-year solar cycle peaks in 2025 during the expected “solar maximum.”

“We are now working on an automated data processing pipeline that will soon produce near-real-time solar images and make them available to the public,” said Chen. “These eclipse images serve as a proof-of-concept for this effort. The unprecedented data products coming soon will open new opportunities for discovery in solar astronomy and space weather studies.”