Michael McGehee News

Researchers take major step toward developing next-generation solar cells

Anonymous — Fri, 22 Mar 2024 21:15:05 +0000

Researchers take major step toward developing next-generation solar cells Anonymous (not verified) Fri, 03/22/2024 - 15:15

The solar energy world is ready for a revolution. Scientists are racing to develop a new type of solar cell using materials that can convert electricity more efficiently than today’s panels.

In a new paper published February 26 in the journal Nature Energy, a ��ñ�� researcher and his international collaborators unveiled an innovative method to manufacture the new solar cells, known as perovskite cells, an achievement critical for the commercialization of what many consider the next generation of solar technology.

Today, nearly all solar panels are made from silicon, which boast an efficiency of 22%. This means silicon panels can only convert about one-fifth of the sun’s energy into electricity, because the material absorbs only a limited proportion of sunlight’s wavelengths. Producing silicon is also expensive and energy intensive.

Enter perovskite. The synthetic semiconducting material has the potential to convert substantially more solar power than silicon at a lower production cost.

Michael McGehee

“Perovskites might be a game changer,” said Michael McGehee, a professor in the Department of Chemical and Biological Engineering and fellow with ��ñ��’s Renewable & Sustainable Energy Institute.

Scientists have been testing perovskite solar cells by stacking them on top of traditional silicon cells to make tandem cells. Layering the two materials, each absorbing a different part of the sun’s spectrum, can potentially increase the panels’ efficiency by over 50%.

“We're still seeing rapid electrification, with more cars running off electricity. We’re hoping to retire more coal plants and eventually get rid of natural gas plants,” said McGehee. “If you believe that we're going to have a fully renewable future, then you're planning for the wind and solar markets to expand by at least five to ten- fold from where it is today.”

To get there, he said, the industry must improve the efficiency of solar cells.

But a major challenge in making them from perovskite at a commercial scale is the process of coating the semiconductor onto the glass plates which are the building blocks of panels. Currently, the coating process has to take place in a small box filled with non-reactive gas, such as nitrogen, to prevent the perovskites from reacting with oxygen, which decreases their performance.

“This is fine at the research stage. But when you start coating large pieces of glass, it gets harder and harder to do this in a nitrogen filled box,” McGehee said.

McGehee and his collaborators set off to find a way to prevent that damaging reaction with the air. They found that adding dimethylammonium formate, or DMAFo, to the perovskite solution before coating could prevent the materials from oxidizing. This discovery enables coating to take place outside the small box, in ambient air. Experiments showed that perovskite cells made with the DMAFo additive can achieve an efficiency of nearly 25% on their own, comparable to the current efficiency record for perovskite cells of 26%.

The additive also improved the cells’ stability.

Commercial silicon panels can typically maintain at least 80% of their performance after 25 years, losing about 1% of efficiency per year. Perovskite cells, however, are more reactive and degrade faster in the air. The new study showed that the perovskite cell made with DMAFo retained 90% of its efficiency after the researchers exposed them to LED light that mimicked sunlight for 700 hours. In contrast, cells made in the air without DMAFo degraded quickly after only 300 hours.

While this is a very encouraging result, there are 8,000 hours in one year, he noted. So longer tests are needed to determine how these cells hold up overtime.

“It’s too early to say that they are as stable as silicon panels, but we're on a good trajectory toward that,” McGehee said.

The study brings perovskite solar cells one step closer to commercialization. At the same time, McGehee’s team is actively developing tandem cells with a real-world efficiency of over 30% that have the same operational lifetime as silicon panels.

McGehee leads a U.S. academic–industry partnership called Tandems for Efficient and Advanced Modules using Ultrastable Perovskites (TEAMUP). Together with researchers from three other universities, two companies and a national laboratory, the consortium received $9 million funding from the U.S. Department of Energy last year to develop stable tandem perovskites that can feasibly be used in the real world and are commercially viable. The goal is to create tandem more efficient than conventional silicon panels and equally stable over a 25-year period.

With higher efficiency and potentially lower price tags, these tandem cells could have broader applications than existing silicon panels, including potential installation on the roofs of electric vehicles. They could add 15 to 25 miles of range per day to a car left out in the sun, enough to cover many people’s daily commutes. Drones and sailboats could also be powered by such panels.

After a decade of research in perovskites, engineers have built perovskite cells that are as efficient as silicon cells, which were invented 70 years ago, McGehee said. “We are taking perovskites to the finish line. If tandems work out well, they certainly have the potential to dominate the market and become the next generation of solar cells,” he said.

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Advancing next-gen solar technology

Anonymous — Wed, 13 Dec 2023 20:24:47 +0000

Advancing next-gen solar technology Anonymous (not verified) Wed, 12/13/2023 - 13:24

National ��ñ��-led consortium aims to enable the commercialization of perovskite-silicon tandem solar cells

The U.S. Department of Energy Solar Energy Technologies Office (SETO) has funded a major new research consortium at the Renewable and Sustainable Energy Institute (RASEI) at ��ñ��. Tandems for Efficient and Advanced Modules using Ultrastable Perovskites, or TEAMUP, is poised to enhance the resilience of tandem perovskite-silicon solar modules, enabling scaling and manufacturing, and ultimately ushering in the next generation of more affordable and efficient solar energy.

Nine million dollars in funding over three years will support collaborative research across four academic institutions (Arizona State University, ��ñ��, Northwestern University and University of California Merced), three industrial companies (Beyond Silicon, Swift Solar and Tandem PV) and one national laboratory (National Renewable Energy Laboratory, or NREL). The consortium will bring together expertise in: manufacturing perovskites, a cutting-edge material for harvesting solar energy; placing perovskite materials into electronic devices to harvest the electricity generated; and layering the new technology into existing silicon-based solar panels to rapidly integrate perovskite technology into current solar infrastructure.

Solar panels must perform in unforgiving environments, including a wide range of temperatures and weather conditions. TEAMUP, led by chemical and biological engineering Professor Mike McGehee, will focus on improving the durability of these materials to increase the stability and efficiency of the solar cells, ultimately helping drive down costs.

“People choose the option that saves them money, so by making solar cells less expensive, it’s really going to help the environment,” said McGehee.

First introduced in the 1950s, modern solar panels use silicon as the semiconductor. However, manufacturing silicon is expensive and energy intensive, which has driven many researchers to focus on replacing silicon with solar panels made completely from perovskite materials. Unfortunately, these next-generation panels are many years away. Tandem perovskite-silicon solar cells, which use a layer of perovskite placed on top of existing silicon-based technology, are more efficient and could enable panels to produce 50% more power. The opportunity to integrate perovskite with today’s silicon cells and modules, and the potential to reach gigawatt production milestones on a timescale attractive to investors and manufacturers for commercialization and deployment, is driving interest in this area.

Two approaches have emerged for combining the perovskite and silicon technologies. The ‘monolithic’ approach directly combines the perovskite and silicon together into a single-piece solar module. In the alternative ‘mechanically stacked’ approach, separate pieces of perovskite and silicon materials are stacked, with the perovskite layer on top.

Which approach to pursue? Instead of focusing exclusively on a single approach, TEAMUP has brought together experts in both approaches to work together and learn from each other. Creating a research ecosystem that fosters creative collaboration above competition is central to this consortium.

“We have an extraordinary team who bring many different types of expertise and I look forward to seeing what we can accomplish,” said McGehee.

“Tandem PV and Swift Solar have long sought to work directly together and with the broader U.S. research community on common research topics that can be solved more quickly as a group. We are excited by the opportunity to work on the same team and not as competitors,” said Colin Bailie, founder and CEO of Tandem PV.

Solving these stability issues and making this new technology durable enough to stand up to the rigors of life in the sun could have a significant impact on the broader economy.

“Perovskite-silicon tandems represent not only the opportunity to make solar more affordable for more communities in the U.S., but also a unique opportunity to return the U.S. to a position of leadership in solar manufacturing and develop a domestic manufacturing base around this new technology,” said Bailie.

Tomas Leijtens, cofounder and chief technology officer for Swift Solar, agreed. “We’re excited to work with this diverse team to tackle the most pressing stability and performance challenges as we scale up perovskite solar technology. This consortium should help accelerate perovskite tandem commercialization in the U.S.”

Images: Mike McGehee and Tomas Leitjens working on solar cells; a stacked illustration of how the perovskite layer (purple layer) will be laid on top of the existing silicon technology (grey-scaled layer), representing both the monolithic and mechanically stacked configurations. Images by: Daniel Morton.

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A new kind of solar cell is coming: is it the future of green energy?

Anonymous — Thu, 30 Nov 2023 23:45:42 +0000

A new kind of solar cell is coming: is it the future of green energy? Anonymous (not verified) Thu, 11/30/2023 - 16:45

Prof. Mike McGehee is featured in this Nature article...

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TEAMUP Consortium funded to develop more stable and affordable tandem solar cells

Anonymous — Thu, 20 Apr 2023 22:59:35 +0000

TEAMUP Consortium funded to develop more stable and affordable tandem solar cells Anonymous (not verified) Thu, 04/20/2023 - 16:59

New consortium aims to accelerate the introduction of the next generation of solar panels

The TEAMUP consortium, that brings together researchers from Academic, Industrial and Federal Laboratories, seeks to identify and solve the factors that cause advanced perovskite materials to be unstable, paving the way for the integration into existing and future solar cells, boosting the efficiency of harvesting renewable solar energy.

In the last ten years a huge amount of research has focused on the use of Perovskite materials as semiconductors that can be tuned to harvest energy from the sun. Light from the sun excites electrons in the perovskite material, and through clever engineering these electrons can be harnessed to produce electric current. First introduced in the 1950s, modern solar panels use silicon as the semiconductor. Silicon requires a lot of energy to produce and is expensive to manufacture, factors which have driven many researchers to replace silicon with perovskite-based systems – however that technology is still someway off, and we need better solar energy systems right now.

Tandems for Efficient and Advanced Modules using Ultrastable Perovskites, or TEAMUP, a project that has just secured $9M in federal funding from the U.S. Department of Energy Solar Technologies Office (SETO), brings together a consortium of researchers from Academic (��ñ��, Northwestern University, Arizona State University and UC Merced), Industrial (Swift Solar, Tandem PV and Beyond Silicon) and Federal Labs (the National Renewable Energy Laboratory), who have a near term solution for more efficient solar panels using a combination of the new perovskite-based systems and the existing silicon-based systems. So-called Tandem perovskite-silicon solar modules bring together the best of both technologies by putting a layer of perovskite on top of silicon-based devices, boosting the efficiency of capturing solar power. Because this approach builds on top of existing silicon-based technologies instead of completely replacing it, it can be more quickly realized and deployed, even potentially upgrading existing installations. Accessing these more efficient and affordable solar energy harvesting technologies is crucial for transitioning more communities to renewable energy sources in a fair and just fashion.

The tandem perovskite-silicon research community is currently working to answer three main questions on the path to commercialization; how to combine the perovskite and silicon devices (monolithic or mechanically stacked tandems), how to create and process the perovskite layer (vapor or solution processing) and how to make the tandem devices more stable and robust. The TEAMUP consortium has chosen not to limit their research focus by selecting one particular device strategy or processing approach and instead adopting a collaborative approach that brings together expertise across these disciplines to address the stability of tandem solar modules. By working together in this unique innovation ecosystem, one in which researchers who might otherwise be considered competitors can openly share the advantages and disadvantages of each approach, understanding of the challenges can be enhanced and realization of solutions that are applicable broadly, across the different strategies, can be accelerated.

Mike McGehee, the lead investigator from ��ñ�� says “We have an extraordinary team who bring many different types of expertise to the Consortium and I look forward to seeing what we can accomplish”. Colin Bailie, Founder and CEO of Tandem PV comments on the collaborative nature of this project “Tandem PV and Swift Solar have long sought to work directly together and with the broader US research community on common research topics that can be solved more quickly as a group. We are excited by the opportunity to work on the same team and not as competitors”.

“We have an extraordinary team who bring many different types of expertise to the Consortium and I look forward to seeing what we can accomplish” - Mike McGehee, TEAMUP lead PI

The key to long-term, real-world operation of these solar modules is the stability of these systems. Solar panels are expected to survive extreme conditions – the heat of the day and the cold of night can provide significant swings in temperature, humidity and general weather scenarios. Under these conditions the perovskite materials can degrade – in the same way that a metal can rust. This can cause reduction in performance efficiencies and lead to blistering in the solar modules. Researchers in TEAMUP are developing strategies to contain and protect the perovskite layers from degradation and enhance stability and real-world operation.

The teams have outlined a two-stage iteration process; innovation followed by comprehensive testing. The innovation stage will explore different perovskite materials, device structures and fabrication approaches. The testing stage will use a comprehensive suite of tools to simulate long-term use under real-world conditions and characterize how these new solar modules perform, the experience and understanding from which will be fed back into the innovation stage. By collecting data at every step of this feedback process TEAMUP will build detailed forecasting models capable of describing performance in real world conditions over a 25 year period, a critical tool in taking this technology to a commercial product.

The importance of the tandem module technology was highlighted by Colin Bailie “Perovskite-silicon tandems represent not only the opportunity to make solar more affordable for more communities in the US, but also a unique opportunity to return the United States to a position of leadership in solar manufacturing and develop a domestic manufacturing base around this new technology. TEAMUP’s success will ensure perovskite-silicon tandems are in a strong technological position as companies prepare for mass production”. Tomas Leijtens, Co-Founder and CTO of Swift Solar agrees “We’re excited to work with this diverse team to tackle the most pressing stability and performance challenges as we scale up perovskite solar technology. This consortium should help accelerate perovskite tandem commercialization in the US”.

Understanding and solving the degradation mechanisms that negatively impact stability in tandem perovskites is essential to demonstrating their feasibility to future investors and customers. By adopting an approach that is agnostic to both perovskite processing and device design, TEAMUP will develop solutions that can be applied across a wide cross-section of the perovskite industry.

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McGehee, Toney and Yin recognized as highly cited researchers

Anonymous — Mon, 22 Nov 2021 16:53:03 +0000

McGehee, Toney and Yin recognized as highly cited researchers Anonymous (not verified) Mon, 11/22/2021 - 09:53

Jonathan Raab

McGehee, Toney and Yin

Three Materials Science and Engineering faculty members were recognized by Clarivate as highly cited researchers this year. Clarivate recognizes "the production of multiple highly-cited papers that rank in the top 1% by citations for field and year" via their Web of Science platform.

The three faculty recognized were Professor Michael McGehee, Professor Michael Toney and Assistant Professor Xiaobo Yin.

Professor Michael McGehee of the Department of Chemical and Biological Engineering, Renewable and Sustainable Energy Institute and the National Renewable Energy Laboratory specializes in perovskite solar cells and dynamic windows with adustable tinting for sustainable energy production and efficiency.

Professor Michael Toney of the Department of Chemical and Biological Engineering focuses on studying the underlying physics and chemistry of materials for sustainable energy, as well as the social justice implications of clean energy.

Assistant Professor Xiaobo Yin of the Paul M. Rady Mechanical Engineering Department specializes in nanomaterials and metamaterials, synthetic materials with novel properties and mechanic and electronic properties not found in nature.

These researchers were among 17 faculty from ��ñ�� recognized this year.

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McGehee and Smalyukh draw DOE funding for building energy efficiency projects

Anonymous — Thu, 02 Sep 2021 20:31:18 +0000

McGehee and Smalyukh draw DOE funding for building energy efficiency projects Anonymous (not verified) Thu, 09/02/2021 - 14:31

Jonathan Raab

Professor Michael McGehee and Professor Ivan Smalyukh are the principal investigators on two Department of Energy-funded projects to improve building technologies and energy efficiency in the built environment. Their projects are among 44 nationwide research projects selected as part of the Building Technologies Office’s competitive Building Energy Efficiency Frontiers & Innovation Technologies funding program.

The projects were selected under the program’s Topic Area 2, Advanced Building Construction category for building envelope research, development and field validation.

Professor Smalyukh is the principal investigator on a project to develop thin-film monolithic mesoporous metamaterials for ultrahigh-efficiency glazing solutions for use on windows with insulating capabilities that meet or exceed that of walls. This will allow buildings to let in natural sunlight during the day without compromising their thermal efficiency.

Professor Michael McGehee is working with his local startup, TYNT Technologies, to develop dynamic windows that feature reversible metal electrodeposition, a process that is less expensive than current manufacturing methods by a significant margin.

The Department of Energy’s investment in building energy efficiency totals nearly $83 million across 44 projects.

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