Piecing together the puzzle of future solar cell materials

Chalmers University of Technology

LinkedIn

Email

 

image: 

Formamidinium lead iodide is considered one of the best-performing materials in the halide perovskite group, since it has promising properties for future solar cell technologies. New findings from Chalmers can now shed light on its structure; this is crucial if we are to engineer and control the material.

view more 

Credit: Chalmers

Global electricity use is increasing rapidly and must be addressed sustainably. Developing new materials could give us much more efficient solar cell materials than at present; materials so thin and flexible that they could encase anything from mobile phones or entire buildings. Using computer simulation and machine learning, researchers at Chalmers University of Technology in Sweden have now taken an important step towards understanding and handling halide perovskites, among the most promising but notoriously enigmatic materials.

Electricity use is constantly increasing globally and, according to the International Energy Agency, its proportion of the world’s total energy consumption is expected to exceed 50 per cent in 25 years, compared to the current 20 per cent.

“To meet the demand, there is a significant and growing need for new, environmentally friendly and efficient energy conversion methods, such as more efficient solar cells. Our findings are essential to engineer and control one of the most promising solar cell materials for optimal utilisation. It’s very exciting that we now have simulation methods that can answer questions that were unresolved just a few years ago,” says Julia Wiktor, the study’s principal investigator and an associate professor at Chalmers.

Promising materials for efficient solar cells

Materials lying within a group called halide perovskites are considered the most promising for producing cost-effective, flexible and lightweight solar cells and optoelectronic devices such as LED bulbs, as they absorb and emit light extremely efficiently. However, perovskite materials can degrade quickly and knowing how best to utilise them requires a deeper understanding of why this happens and how the materials work.

Scientists have long struggled to understand one particular material within the group, a crystalline compound called formamidinium lead iodide. It has outstanding optoelectronic properties. Greater use of the material has been hampered by its instability but this can be solved by mixing two types of halide perovskites. However, more knowledge is needed about the two types so that researchers can best control the mixture.

The key to material design and control

A research group at Chalmers can now provide a detailed account of an important phase of the material that has previously been difficult to explain by experiments alone. Understanding this phase is key to being able to design and control both this material and mixtures based on it. The study was recently published in Journal of the American Chemical Society.

“The low-temperature phase of this material has long been a missing piece of the research puzzle and we’ve now settled a fundamental question about the structure of this phase," says Chalmers researcher Sangita Dutta.

Machine learning contributed to the breakthrough

The researchers’ expertise lies in building accurate models of different materials in computer simulations. This allows them to test the materials by exposing them to different scenarios and these are confirmed experimentally.

Nevertheless, modelling materials in the halide perovskite family is tricky, as capturing and decoding their properties requires powerful supercomputers and long simulation times.

“By combining our standard methods with machine learning, we’re now able to run simulations that are thousands of times longer than before. And our models can now contain millions of atoms instead of hundreds, which brings them closer to the real world,” says Dutta.

Lab observations match the simulations

The researchers identified the structure of formamidinium lead iodide at low temperatures. They could also see that the formamidinium molecules get stuck in a semi-stable state while the material cools. To ensure that their study models reflect reality, they collaborated with experimental researchers at the University of Birmingham. They cooled the material to - 200°C to ensure their experiments matched the simulations.

"We hope the insights we’ve gained from the simulations can contribute to how to model and analyse complex halide perovskite materials in the future," says Erik Fransson, at the Department of Physics at Chalmers.

 

More about the research:

The article Revealing the Low Temperature Phase of FAPbI3 using A Machine-Learned Potential was published in Journal of the American Chemical Society on 14th August 2025 and was written by Sangita Dutta, Erik Fransson, Tobias Hainer, Benjamin M. Gallant, Dominik J. Kubicki, Paul Erhart and Julia Wiktor. The researchers are all members of the Department of Physics at Chalmers University of Technology, except for Gallant and Kubicki, who are from the School of Chemistry, University of Birmingham.

The research was supported by the Swedish Foundation for Strategic Research, the Swedish Energy Agency, the Swedish Research Council, the European Research Council, the Knut and Alice Wallenberg Foundation and the Nano Area of Advance at Chalmers University of Technology. The calculations were facilitated by resources from the National Academic Infrastructure for Supercomputing in Sweden (NAISS) at C3SE.

 

Caption: Formamidinium lead iodide is considered one of the best-performing materials in the halide perovskite group, since it has promising properties for future solar cell technologies. New findings from Chalmers can now shed light on its structure; this is crucial if we are to engineer and control the material.

 

For more information, please contact:

Julia Wiktor, Associate Professor, Department of Physics, Chalmers University of Technology, +46 31 772 59 36 julia.wiktor@chalmers.se

Sangita Dutta, Postdoc, Department of Physics, Chalmers University of Technology, sangita.dutta@chalmers.se

 

---

Journal

Journal of the American Chemical Society

DOI

10.1021/jacs.5c05265 

Method of Research

Computational simulation/modeling

Subject of Research

Not applicable

Article Title

Revealing the Low-Temperature Phase of FAPbI3 Using a Machine-Learned Potential

LITERALLY

Supercritical subsurface fluids open a window into the world

Advanced visualizations and AI reveal how high-pressure fluids influence seismic activity

University of Tokyo

Facebook

WeChatBlueskyMessageWhatsAppEmail

 

image: 

The seal layer, interpreted by looking at data on the supercritical fluid’s movement, appears as a distinct region. It’s disrupted where it meets a fault which makes it appear porous to the fluid, allowing it to migrate upwards, causing seismic vibrations. ©2025 Tsuji et al. CC-BY

view more 

Credit: ©2025 Tsuji et al. CC-BY

Researchers including those from the University of Tokyo build on past studies and introduce new methods to explore the nature and role of subsurface fluids including water in the instances and behaviors of earthquakes and volcanoes. Their study suggests that water, even heavy rainfall, can play a role in or even trigger seismic events. This could potentially lead to better early warning systems. The study improves models of seismic activity and can even help identify optimal sites for drilling to tap sources of supercritical geothermal energy.

As far as is currently known, earthquakes and volcanic eruptions cannot be predicted, certainly not on the timescales with which we expect from typical weather reports. But as physical theories improve, so does the accuracy of statistical models which could be useful for planning, and potentially also early warning systems, which can save lives when disaster does strike. Another benefit of improving such models is that they could help locate areas suitable for tapping into geothermal energy. So, it’s the improvement of theories, based on good observations, that geologists and other researchers strive for. And a recent development in this field has added another factor into the mix which may be more significant than was previously thought.

“Our latest paper using advanced seismic imaging shows, for the first time, how deep volcanic fluids, such as water, in their high-pressure supercritical state, can become trapped, migrate and undergo phase changes that influence earthquakes,” said Professor Takeshi Tsuji from the Graduate School of Engineering at the University of Tokyo. “Applying machine learning to our seismometer data allowed us to map earthquake distribution and mechanism in detail, and to investigate the brittle-ductile transition zone, where rocks change from seismically active to largely inactive. This is a prime area for fluids to accumulate. Unlike earlier low-resolution electromagnetic surveys, our seismic approach revealed these systems in unprecedented three-dimensional detail.”

Supercritical fluids are the key here. They are special because they act like both a liquid and a gas. Due to high pressures and temperatures, they flow easily like gas but with the ability to store and transfer huge amounts of heat like a liquid. This means as they pass through different mediums or a medium with varying conditions, for example a tightly sealed area to one that’s fractured, supercritical fluids can rapidly heat an area changing how it and the magma beneath it behave. And this supercritical fluid is not isolated from the world; it can even be affected by the rain.

“When heavy rain falls, the groundwater level rises, increasing pressure in cracks and faults deep below. If those faults are already close to breaking, this added pressure can trigger earthquakes,” said Tsuji. “In volcanic areas, where the crust is weakened by high-pressure fluids, this effect can be especially strong. Our study clearly showed a correlation between rainfall and seismicity. By imaging magma and understanding how pressure builds up underground, we may improve how we look for early warning signs of eruptions.”

Beyond predicting disasters, though, comes a potentially great benefit: the chance to tap into nearly limitless clean geothermal energy, something a country like Japan is ideally suited to do but has not yet taken the plunge. The project began as a means to find reliable drilling targets to more easily reach the supercritical water reserves necessary for realizing geothermal power use. With their new method, Tsuji and his team were able to identify fluid pathways, reservoirs beneath sealed layers, and the fractures that let fluids escape.

“Underground supercritical water contains vast thermal energy, making it an incredibly promising renewable resource in the future. Importantly, because it is drawn from deep reservoirs, it does not interfere with surface hot spring systems, a major concern for geothermal power in Japan,” said Tsuji. “The main obstacle to widespread use of supercritical geothermal energy is drilling. These fluids exist at great depths under extreme pressure and temperature, so both drilling technology and equipment must be adapted. Even though we can now locate supercritical fluids and their reservoirs, we still need to develop safe and efficient designs for wells to make this energy resource practical.”

###

Journal: Takeshi Tsuji, Rezkia Dewi Andajani, Masafumi Katou, Akio Hara, Naoshi Aoki, Susumu Abe, Hao Kuo-Chen, Zhuo-Kang Guan, Wei-Fang Sun, Sheng-Yan Pan, Yao-Hung Liu, Keigo Kitamura, Jun Nishijima, Haruhiro Inagaki, “Supercritical fluid flow through permeable window and phase transitions at volcanic brittle–ductile transition zone”, Communication Earth & Environment, DOI: 10.1038/s43247-025-02774-4

Funding: This study was supported by the New Energy and Industrial Technology Development Organization (NEDO) and was partially supported by the Japan Society for the Promotion of Science (JSPS) KAKENHI program (Grant Numbers JP21H05202, JP22H05108, and JP24H00440).

 

Useful links:

Graduate School of Engineering – https://www.t.u-tokyo.ac.jp/en/

Department of Systems Innovation - https://www.sys.t.u-tokyo.ac.jp/en/?lang=en

The data for this project were gathered in the region of Kuju in Kyushu, western Japan. The map shows sites of volcanoes and the seismometers recording seismic activity and two geothermal power plants, demonstrating there is already appetite for this energy source. ©2025 Tsuji et al. CC-BY

Credit

©2025 Tsuji et al. CC-BY

Credit

©2025 Tsuji et al. CC-BY

Credit

©2025 Tsuji et al. CC-BY

---

Journal

Communications Earth & Environment

DOI

10.1038/s43247-025-02774-4 

Method of Research

Observational study

Subject of Research

Not applicable

Article Title

Supercritical fluid flow through permeable window and phase transitions at volcanic brittle–ductile transition zone

Article Publication Date

24-Sep-2025

Early symptoms of MS same across ethnic and social groups – study

Study reveal early warning signs of multiple sclerosis appear years before diagnosis

Queen Mary University of London

FacebookLinkedInWeChatBlueskyMessage

WhatsAppEmail

A major UK study has revealed that the early warning signs of multiple sclerosis (MS) - including pain, mood changes, and neurological symptoms such as numbness and tingling – may appear years before diagnosis and affect all communities in similar ways.  

Researchers at Queen Mary University of London analysed electronic health records of more than 96,000 people, including 15,000 people with MS, making this one of the largest and most diverse investigations into the MS prodrome – the constellation of non-specific symptoms experience by people with MS before a diagnosis– to date. While the MS prodrome is a well-documented phenomenon, little is known about whether or how symptoms during this period vary depending on ethnicity or socio-economic status. A better understanding of this phase across the entire population could help our understanding of the onset of the disease and could aid in early diagnosis. 

The study, published in Annals of Clinical and Translational Neurology, confirms that these early symptoms are consistent across gender, ethnicity and socio-economic backgrounds, strengthening the case for these symptoms being used to help detect MS earlier. 

The researchers found that, in the five years before diagnosis, people with MS were:  

• 8 times more likely to report neurological symptoms such as vision changes or numbness 
• 2.5 times more likely to have memory or concentration problems  
• Twice more likely to report chronic pain or bladder/bowel issues 
• 1.7 times more likely to experience depression or anxiety  

These patterns hold true for people of White, Black, South Asian and mixed/other ethnicities, as well as those living in both rural and urban areas. 

Ruth Dobson, Professor of Clinical Neurology at Queen Mary and lead author of the study said: “This is the strongest evidence yet that MS gives us clues years before diagnosis. If doctors know what to look for, they can potentially spot the disease earlier and act to start treatment before significant damage is done.”  

Interestingly, the link between neurological symptoms and later MS diagnosis was even stronger for men and people from Black and Asian backgrounds. These are groups that are often typically less likely to be diagnosed with MS overall.  

Ben Jacobs, Clinical Lecturer in Neurology at Queen Mary and co-author on the study said: “Our study shows that the very earliest features of MS are similar regardless of someone’s ethnic or socio-economic background. Efforts to detect MS earlier or identify people at high risk should therefore be inclusive and representative of the whole population.” 

Why it matters 

MS is a chronic neurological condition affecting 150,000 people in the UK and more than two million people worldwide. Early diagnosis and treatment can slow progression, reduce disability and improve quality of life. 

However, diagnosis is often delayed until a major neurological episode occurs, sometimes after years of unexplained symptoms. These new findings could help doctors identify people at high risk much sooner.  

Dr Catherine Godbold, Senior Research Communications Manager at the MS Society, says: "Understanding more about the early signs of MS could help speed up MS diagnosis and get people onto treatments sooner. This can help to slow down disease progression and prevent disability. So, we're really pleased to see these early symptoms being studied in a large, diverse group.  

“Over 150,000 people live with MS in the UK, and the condition can affect all communities, ages, ethnic backgrounds and genders. But almost everything we know about how MS develops is based on people of White ethnicity. Research like this is crucial in helping us ensure healthcare services can benefit everyone living with MS and those at an increased risk of developing the condition, regardless of their background.” 

The research team is now working on risk prediction tools that could flag high-risk individuals for closer monitoring or referral. This could pave the way for trials of preventive treatments, shifting MS care from reactive to proactive. 

The study used anonymised data from the Clinical Practice Research Datalink (CPRD) Aurum, which covers around 20 per cent of the UK population. It was funded by the National Multiple Sclerosis Society (NMSS). 

ENDS 

---

Journal

Annals of Clinical and Translational Neurology

DOI

10.1002/acn3.70175 

Method of Research

Observational study

Subject of Research

People

Article Title

Pre-diagnostic features of Multiple Sclerosis in a diverse UK cohort: a nested case-control study

Article Publication Date

24-Sep-2025

COI Statement

RD has received honoraria for speaking and/or travelling from Biogen, Merck, Teva, Roche, Janssen and Sanofi. She served on advisory boards for Roche, Biogen, Janssen and Merck and study steering committees for Roche. All honoraria are paid into an institutional account and used to support research and training. She has received grant support from Biogen, Merck, Celgene. PT, JB and BJ report no disclosures

PALEONTOLOGY

From mosasaurs to snakes and lizards, “megafilters” shape reptile fossil collections

The environment and the durability of their bones are the drivers behind which reptiles—and which parts of reptiles—end up shaping museum collections and our understanding of the fossil record

Natural History Museum of Los Angeles County

LinkedInWeChatBlueskyMessageWhatsAppEmail

 

image: 

The global fossil record of squamates, which includes lizards, mosasaurs, snakes, and amphisbaenians (A) is overwhelmingly incomplete, with most fossil species containing less than 20% of the totality of physical characteristics observable in their skeletal remains (B). C-G include examples of fossil species with various completeness scores. 
 

view more 

Credit: Hank Woolley

For the more than 242 million years that lizards and snakes appear in the fossil record, they show up as mostly pieces of lizard jaws and snake vertebrae. Exactly why these parts survive as fossils has been a mystery—until now.

In a new study published in Paleobiology, Dr. Hank Woolley from the Natural History Museums of Los Angeles County’s Dinosaur Institute looks at the entire history of squamates (the reptile group that includes lizards, snakes, and mosasaurs among others) to understand why only certain parts show up—the bias of the record—and to quantify that bias for the first time. Woolley and his co-authors found that physical characteristics like bone density and body size, along with where the animals lived and died, were the main predictors of how complete a fossil would be. Woolley identifies these patterns as megafilters, which refer to processes that have an outsized effect on the way we understand the fossil record. This unprecedented high-resolution view of the group’s biodiversity through multiple mass-extinction events illuminates mysteries of squamates’ evolutionary history and can help guide future work that examines how animals are preserved as fossils. 

 

Woolley and colleagues examine in detail the relationship between inferred environments in which a fossil squamate species was buried and the completeness of its remains. Environmental and geological processes play a strong role in how complete the fossil record can be. You’ll notice that mosasaurs are almost exclusively found in marine settings and are more complete on average than other groups. Snakes, on the other hand, are found nearly everywhere, but are highly incomplete.

Hank Woolley

“Squamates are super adaptable, widespread, and incredibly diverse throughout their whole evolutionary history,” says Woolley. “However, our new study shows that the majority of fossil squamate species are known from incomplete and scrappy skeletal material: isolated jaw bones and vertebrae. Understanding why this happens on global scales is a key first step in sorting through the biases that have stood in the way of having a clear picture of the history of this important group of animals.”

Many people took up hobbies like baking sourdough bread over the COVID-19 lockdowns, but nobody on Earth took up  Dr. Woolley’s pandemic project: reading every paper describing a squamate fossil from their 240ish million years on the planet. “I think it's almost 500 papers,” says Woolley. The study leverages the first digital revolution of museum science and newly digitized collections made available to researchers around the world, and is a product of the second digital revolution, where those collections are combined into databases, such as the Paleobiology Database, letting researchers like Woolley get a bigger, clearer picture than ever before of the totality of the fossil record. But to understand how complete each fossil was, he had to dive into each published paper describing the fossils in those digitized collections, hence the pandemic reading project.

“It was the only way to look at each bone that's described and count it towards the completeness of what we know about a squamate species. We just don’t have that level of detailed information available yet from the Paleobiology Database, and hopefully, studies like ours can help build toward more and more comprehensive information available to researchers online. For the time being,  you still have to go to the papers and museum collections themselves.” 

The purpose of this deep dive was to explore the concept of megabiases—things like regional/global geologic processes and human-based sampling issues—and how they shape our fossil data. From a human-based sampling perspective, examples of megafilters could include whether resources have been mustered to explore one particular region over others, or asymmetries in the number of scientists researching a group of organisms—dinosaurs get more attention than the smaller creatures living among them, for example. 

The key finding of this study is that the chief determinants of how complete a squamate fossil can be are how durable the bones themselves are (for example, bigger bones and fused bones are more resistant to decay and breakage over time), and the environment in which the squamate species died and was buried in (like a river, lake, desert, or open ocean). Woolley and his co-authors found that human-based sampling issues, which can be the main culprit in fossil record completeness in other groups of animals like dinosaurs, appear to play a secondary role in determining the completeness of a fossil squamate species.
 

Having such a clear picture of squamates’ history through deep time could be key to answering some of the questions around this incredibly diverse group of reptiles. For instance, the extinct group of marine lizards known as mosasaurs has the most complete fossil record of any squamate group. The relative incompleteness of other squamate groups’ fossil records may play a role in obscuring mosasaurs’ evolutionary history. 

 

LACM 128319, on display in NHMLAC’s Dinosaur Hall, is an exceptionally preserved specimen belonging to the mosasaur Platecarpus tympaniticus. This is just one of the many examples of exquisite mosasaur fossils that contribute to our more complete understanding of their record compared to other squamate groups.

“Paleontologists disagree about where mosasaurs fit on the squamate tree of life,” says Woolley. “Some workers think they're related to snakes, some think they're related to monitor lizards, and some hypotheses place them in a completely different part of the tree.” All this data could make it easier to find a reptile-sized hole in Mosasaur evolutionary history.  

Understanding the biases in collections could also help researchers understand how these giants of the Mesozoic oceans radiated across the globe so quickly, and how other squamates, like lizards and snakes, survived mass extinction events and thrive today. “Between the early evolutionary history of groups and after mass extinction events, this study helps identify key gaps in the fossil record that have the potential to teach us a lot about these lizards and snakes that are around today,” says Woolley.

 

The global fossil record of squamates, which includes lizards, mosasaurs, snakes, and amphisbaenians (A) is overwhelmingly incomplete, with most fossil species containing less than 20% of the totality of physical characteristics observable in their skeletal remains (B). C-G include examples of fossil species with various completeness scores.

Hank Woolley

“This study is a great example of how the next generation of paleontologists like Hank are taking advantage of digitized records such as the Paleobiology Database, and combining them with the sweat equity spent combing through the literature and museum collections to help answer “big-picture” questions about the bias and quality of the fossil record.” says co-author and Gretchen Augustyn Director & Curator of the Dinosaur Institute Dr. Nathan Smith. “Darwin himself devoted a whole chapter of the Origin of Species to the imperfection of the fossil record, but Hank’s work is helping to finally quantify those biases and tease out how they impact our understanding of the evolutionary history of major vertebrate groups.”

Rather than being discouraged by the inherent “low ceiling” of lizard and snake remains to end up as complete fossils, Woolley points to ground-breaking research and rich data yet to be gleaned from fragmentary fossils. “If we don't quantify these biases,  we could be overlooking some of the very real information that these incomplete fossils can give us,” says Woolley. It’s a promising case study that shows a better understanding of other collections of fragmentary fossils is possible. “Continuing to build these detailed fossil datasets can only help our endeavor to understand how our Earth system’s natural processes—and how we study fossils—shape the field of paleontology.” 

About the Natural History Museum of Los Angeles County: 
The Natural History Museum (NHM) is one of Los Angeles’ oldest cultural institutions and anchor of the evolving cultural, educational, and entertainment nexus in Exposition Park. NHM’s collection ranges from 4.5-million-year-old meteorites to newly discovered species explored throughout immersive visitor experiences such as Age of Mammals and the award-winning Dinosaur Hall. The outdoor 3.5-acre Nature Gardens and indoor Nature Lab look at people’s relationship with the environment in L.A., while another beloved permanent exhibit, Becoming Los Angeles, examines how L.A. has changed over time. NHM also features industry-leading habitat dioramas, an exquisite gem and mineral hall, a hands-on Discovery Center, and behind-the-scenes experiences such as the Dino Lab, where fossils are prepared in public view. NHM recently opened NHM Commons, a new community-focused wing designed to open new doors to natural history and celebrate the intersections of science, nature, and culture.

MEDIA CONTACTS:

Tyler Hayden
Science Communications Specialist
thayden@nhm.org 

Amy Hood
Director of Communications
ahood@nhm.org 

---

Journal

Paleobiology

DOI

10.1017/pab.2025.10060 

Method of Research

Meta-analysis

Subject of Research

Animals

Article Title

Taphonomic megabiases constrain phylogenetic information in the squamate fossil record

Article Publication Date

24-Sep-2025

LACM 128319, on display in NHMLAC’s Dinosaur Hall, is an exceptionally preserved specimen belonging to the mosasaur Platecarpus tympaniticus. This is just one of the many examples of exquisite mosasaur fossils that contribute to our more complete understanding of their record compared to other squamate groups.

Credit

Courtesy of the Natural History Museum of Los Angeles County

Woolley and colleagues examine in detail the relationship between inferred environments in which a fossil squamate species was buried and the completeness of its remains. Environmental and geological processes play a strong role in how complete the fossil record can be. You’ll notice that mosasaurs are almost exclusively found in marine settings and are more complete on average than other groups. Snakes, on the other hand, are found nearly everywhere, but are highly incomplete.  

 

Credit

Hank Woolley