The new technique hinges on a counterintuitive insight about how perovskites crystallize. By adding a mixture of zinc bromide and methyl ammonium chloride early in the fabrication process, the researchers discovered they could dramatically reduce the number of defects that form in the crystal structure as the material solidifies. The consequences of that seemingly small intervention are striking. In defect-free perovskites produced this way, electrons retain the excess energy they absorb from sunlight roughly ten times longer than in untreated material. According to Dane deQuilettes, assistant professor at Princeton and a senior author on the paper, the improvement could translate into a one percent gain in power generation even for the most cutting-edge perovskite solar cells already in existence — a meaningful margin in a field where incremental gains are fiercely contested.

To understand why those microseconds matter, it helps to grasp what actually happens inside a working solar cell. When sunlight strikes a semiconductor, photons transfer their energy to electrons, lifting them into an excited state. The whole point of a photovoltaic device is to harvest that excess energy as electricity before the electrons relax back down and release it as heat. Defects in the crystal lattice act like traps along this pathway, snaring excited electrons and squandering their energy before it can be collected. The longer electrons can hold onto their excess energy — a property measured in microseconds in these experiments — the more opportunities there are to extract useful power. In deQuilettes’ measurements, electrons in the treated perovskites retained their energy for up to 300 microseconds, roughly a hundred thousand times longer than in many other semiconductors.

The discovery itself was born of serendipity. A few years ago, Jason Yoo, a first author on the paper who was then a researcher at the Korea Research Institute of Chemical Technology, noticed that his samples were behaving in ways he could not explain. He reached out to deQuilettes, whose laboratory specializes in developing tools to probe how electrons behave and interact inside perovskites. “He told me the samples were behaving like nothing he had seen before,” deQuilettes recalled. “He asked if I could help study them.” What deQuilettes found when he examined the samples amazed him: the extraordinary carrier lifetimes that would eventually form the basis of the Science paper.

The chemistry behind the breakthrough is as subtle as it is effective. The key, deQuilettes explained, is that the two added chemicals — zinc bromide and methyl ammonium chloride — must have a lower melting point when combined than either does alone, much as adding salt to ice lowers its freezing point. Such mixtures are known as eutectics, and the paper’s title, “Volatile eutectics to tailor crystallization for perovskite optoelectronics,” reflects this principle. By introducing a volatile eutectic during the early stages of fabrication, the researchers changed the way the perovskite crystal grows, steering it toward a more ordered lattice with fewer of the atomic-scale imperfections that plague conventionally processed films. “We opened up this new class of chemical mixtures that improve the performance of perovskites,” deQuilettes said.

The broader context makes the advance especially significant. Most solar cells installed around the world today are made of silicon, a material prized for its durability but constrained by its physics and its energy-intensive manufacturing. Perovskites, by contrast, can be prepared from liquid precursors and printed in sheets, like ink on newsprint, potentially making them cheaper and more sustainable to produce at scale. Increasingly, the two technologies are being combined rather than competing: a thin coat of perovskite layered over a silicon solar cell forms a tandem device that generates about 40 percent more power than a cell made from either material alone. The catch has always been that the printing and layering process tends to introduce those damaging atomic-level defects, blunting the perovskite layer’s contribution. Fewer defects mean a more efficient perovskite layer, which in turn means more efficient tandem modules rolling off future production lines.

The timing could hardly be more pointed. Global electricity demand is climbing rapidly, driven in no small part by the explosive growth of artificial intelligence and the datacenter infrastructure that underpins it. “The whole solar industry has been asking, what are the next set of technologies that are going to contribute to energy production?” deQuilettes noted. A one percent improvement in power conversion may sound modest, but in the economics of utility-scale solar — where installations span thousands of acres and margins are measured in fractions of a cent per kilowatt-hour — even single-digit percentage gains compound into substantial additional generating capacity. And because the improvement is achieved through chemistry during fabrication rather than through expensive post-processing, it is the kind of change that manufacturers could in principle adopt without redesigning their entire production workflow.

Perhaps the most intriguing implications reach beyond photovoltaics altogether. Because electrons in the treated perovskite persist in their excited state for hundreds of microseconds — an eternity by semiconductor standards — the material opens possibilities that conventional semiconductors simply cannot offer. “Energy is living in the material for so long, it broadens what’s actually possible with a semiconductor,” deQuilettes said. Long carrier lifetimes are coveted not only in solar cells but in a range of optoelectronic applications, from light-emitting devices to photodetectors and potentially quantum technologies, where the ability of a material to hold onto excitation energy determines what device architectures are feasible. The researchers emphasize that the discovery has raised more questions than it has answered. “It’s been really eye-opening,” deQuilettes added, suggesting that the eutectic approach may be only the first entry in what could become a broad family of defect-mitigating chemical mixtures.

The study was a genuinely international effort. In addition to deQuilettes at Princeton and Yoo and Bong Joo Kang at the Korea Research Institute of Chemical Technology, the author list spans Connor J. Dolan, Zhewen J.D. Deng, Jack R. Palmer, Kelly X. Vences and David P. Fenning at the University of California-San Diego; Seongsik Nam, Jinho Lee, Kyu Min Kang, Daesoo Kim, Jang Hee Cho, Donghyuk Chung and Seong Sik Shin at Sungkyunkwan University in Korea; Rushik Desai and Arun Mannodi-Kanakkithodi at Purdue University; Niranjana Mohan Kumar, Mariana I. Bertoni and Arkita Chakrabarti at Arizona State University; Yanqi Luo, Barry Lai, Zhonghou Cai, Martin V. Holt and Tao Zhou at Argonne National Laboratory; Andrew M. Kiss at Brookhaven National Laboratory; and In Sun Cho at Ajou University and Dong Hyun Kim and Jun Hong Noh at Korea University. That breadth of expertise — spanning synthesis, ultrafast spectroscopy, synchrotron characterization and computational modeling — reflects the multidisciplinary challenge of understanding and controlling defects at the atomic scale.

For a field that has weathered its share of hype and hard lessons, the new result offers something refreshingly concrete: a reproducible chemical strategy, published in a peer-reviewed journal, that measurably extends carrier lifetimes by an order of magnitude and points toward real gains in device performance. Perovskites have always been crystals of extraordinary promise; the challenge has been coaxing that promise out of an imperfect lattice. With volatile eutectics now shown to tailor crystallization in a way that suppresses defects at their source, researchers have a new tool — and a new class of chemistry to explore — in the long effort to build better solar technology, one crystal at a time.

Subject of Research: Defect mitigation in perovskite solar cells using volatile eutectic chemical additives during fabrication

Article Title: Building better solar tech, a crystal at a time

Article References: Building better solar tech, a crystal at a time. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: perovskite, solar cells, crystal defects, eutectics, photovoltaics, tandem solar cells, semiconductors, carrier lifetime, zinc bromide, methyl ammonium chloride, Princeton University, Science journal

The research, led by Andreas Bezold, an adjunct assistant professor of materials science and engineering at Ohio State, focused on a pair of model alloys: a cobalt-nickel-based superalloy and a cobalt-chromium-tungsten alloy. Both belong to a class of materials prized for their ability to retain mechanical integrity at elevated temperatures, making them candidates for demanding structural roles. Rather than avoiding deformation, the researchers embraced it. In a two-step process, they first deformed the metal crystals in a controlled manner and then applied heat to slowly age the material. This combination coaxed the microscopic defects generated during deformation into atomically thin, densely packed features embedded within the crystal structure.

What emerged from this treatment was remarkable. The defects organized themselves into what the researchers describe as ordered two-dimensional defect phases: layered arrangements of structural faults enriched within the alloy. Because these features are only an atomic scale thick but spread through the material in dense networks, they act as formidable obstacles to the mechanisms that normally allow metals to deform. When stress is applied, dislocations, the tiny line defects that carry plastic deformation through a crystal, must navigate around or through these engineered barriers. The more densely and intelligently those barriers are arranged, the more force is required to distort the metal, and the stronger the alloy becomes.

The team verified this mechanism using a powerful combination of experimental and computational techniques. Transmission electron microscopy allowed the researchers to image the defect structures directly at atomic resolution, while computer simulations helped them understand how the atoms were arranged around the structural faults and how those arrangements translated into macroscopic strength. The analysis revealed that the boost in strength was intimately linked to the local atomic configuration surrounding the defects. In other words, it was not simply the presence of the faults that mattered, but their precise structure and chemistry. Altering this complex formation could directly influence how strong the resulting material would be.

The performance gains were significant on two fronts. The treated alloys could withstand markedly greater stress before deforming, and they also showed improved resistance to gradual warping at high temperatures, a degradation mode known to engineers as creep. Creep is the slow, cumulative deformation that occurs when metals are held under load for long periods at elevated temperature, and it is one of the principal factors limiting the lifespan of turbine blades, power plant components, and other hot-section hardware. By addressing both strength and creep resistance simultaneously, the defect-engineering approach targets the very properties that constrain the design of high-temperature machinery.

Importantly, the method achieves these gains without changing the chemical composition of the alloys. Conventional alloy design typically relies on adjusting elemental recipes, adding solutes or precipitates to tune properties, but every compositional change can introduce trade-offs in cost, processability, corrosion resistance, or density. The new approach instead works through the material’s internal architecture, arranging atoms via engineered defects while leaving the ingredient list untouched. Bezold noted that defects are very important to learn more about, because understanding how they interact with a material’s internal structure helps scientists design stronger materials. The team’s goal, he said, was to make these strengthening structures a deliberate part of the material’s design, and it was fascinating to see how defects could have such a positive effect on the overall durability of the alloys.

The work builds on earlier Ohio State research showing that microscopic defects formed during deformation can be converted into layers that strengthen a material’s structure. What distinguishes the new study is scale and density. The researchers report that theirs is the first approach to introduce defect densities that fully enrich the alloys, saturating the material with ordered strengthening features rather than producing isolated or sparse ones. That saturation is what allows the defects to act as a genuine design layer, a three-dimensional internal framework that complements, rather than replaces, conventional materials design strategies such as compositional tuning and heat treatment.

Michael Mills, co-author of the study and a professor of materials science and engineering at Ohio State, described the atomic-scale observations as quite stunning. Despite being associated with damage, he explained, the right defects with the right structure and chemistry can actually make a material stronger. That paradox captures the essence of the discovery: the same lattice disruptions that cause failure when uncontrolled can be harnessed to resist failure when deliberately organized. It is a conceptual shift with echoes across materials science, where researchers increasingly treat a material’s internal microstructure, down to individual atomic arrangements, as a programmable variable rather than a fixed consequence of processing.

The practical implications reach toward technologies that must survive brutal thermal and mechanical environments. High-strength alloys engineered with dense defect networks could extend the operating envelopes of aircraft turbine engines, allowing them to run hotter and more efficiently, or improve the longevity of power plant machinery subjected to sustained loads at high temperature. Longer-lasting structural materials also carry sustainability benefits, since components that resist warping and failure need to be replaced less frequently, reducing resource consumption and waste over the lifetime of large engineered systems. The researchers suggest that adding a layer of engineered defects could become a standard complement to existing design principles in structural metallurgy.

For now, Bezold’s team is helping to establish richer design principles for the field, and the researchers see the work as the opening of a fast-moving frontier. This is a field that is quickly becoming very exciting, Bezold said, expressing hope that the idea becomes a new lever that strengthens and pushes the limits of material engineering even further. The study was supported by Ohio State’s Center for Electron Microscopy and Analysis, the Alexander von Humboldt Foundation, the National Science Foundation, and the U.S. Department of Energy. Co-authors include Yunzhi Wang of Ohio State; Manuel Köbrich, Jan Vollhüter, Lukas Amon, Mathias Göken, Steffen Neumeier, Nicolas Karpstein, and Erdmann Spiecker of the University of Erlangen-Nuremberg in Germany; and Longsheng Feng of Lawrence Livermore National Laboratory in California. As the technique matures, the humble crystal defect, once the villain of materials engineering, may become its most valuable ally.

Subject of Research: Defect engineering in metal alloys to enhance strength and creep resistance

Article Title: Enhancing hidden defects to strengthen metal materials

Article References: Enhancing hidden defects to strengthen metal materials. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: materials science, metal alloys, crystal defects, superalloys, transmission electron microscopy, creep resistance, structural materials, cobalt-nickel alloy, cobalt-chromium-tungsten alloy, high-temperature materials, Ohio State University, Science journal

To understand why pairing photons with phonons is such a compelling frontier, it helps to consider what each carrier of energy does best. Photons, the individual quanta of light, are the undisputed champions of communication. They travel at the fastest speed physics allows, they interact only weakly with their surroundings, and they can carry information across intercontinental fiber networks with astonishing fidelity. Phonons, the quantized units of mechanical vibration, are the opposite in temperament. They move slowly, they are easily disturbed by heat, and they almost never travel far in ordinary materials. Yet those same liabilities translate into strengths: phonons can store energy in compact volumes, they couple naturally to nearly every other physical system, and their slow pace gives researchers a handle for manipulating and reading out quantum states that would otherwise be too fleeting to grasp.

The field that exploits this complementarity is known broadly as cavity optomechanics, and its central idea is to place mechanical motion inside an optical resonator so that light can exert exquisitely controlled forces on a vibrating object, while the vibration in turn modulates the light. When the interaction is strong enough, the two systems stop behaving as separate entities and become hybridized, sharing quantum states the way two coupled pendulums share energy. This hybrid regime is where the most exciting applications live. A mechanical oscillator entangled with an optical field could serve as a transducer, converting quantum information from one physical carrier to another. A phonon mode driven by light could act as an extremely narrow filter or delay line for microwave and optical signals. And a massive mechanical object cooled close to its quantum ground state becomes a laboratory for testing whether the strange rules of quantum mechanics survive at scales far larger than atoms.

Renninger’s laboratory has built its reputation on pushing these interactions into new regimes, and the Moore Foundation award will support a program that deliberately spans multiple physical platforms. Rather than confining the work to a single device geometry, the project aims to create light-driven sound devices and measurement methods that operate across integrated photonic chips, surface acoustic wave devices, and bulk crystalline resonators. Each platform occupies a different niche. Chip-scale devices offer tight confinement and strong light-matter interaction, making them ideal for signal processing and integration with existing photonics. Surface acoustic waves, which ripple along the surface of a piezoelectric crystal much like waves across a pond, provide a natural bridge between electrical circuits and mechanical motion, and Rochester researchers have previously explored their potential for future quantum networks. Bulk crystals, meanwhile, can host acoustic modes of exceptional purity, with phonons bouncing back and forth millions of times before dissipating, which is exactly the kind of long-lived storage that quantum technologies demand.

One of the most consequential goals of the program is the generation of strong, narrow-band acoustic responses for optical signal processing. Modern communication systems are straining under demand for bandwidth, and the ability to filter, route, and delay light using sound offers a route to processors that combine the speed of photonics with the selectivity of acoustics. Because phonons oscillate at frequencies many orders of magnitude below those of optical carriers, they provide a natural clockwork for manipulating light with fine spectral resolution. A device that converts an optical signal into a phonon, holds it briefly, and converts it back can function as a tunable delay line or a frequency-selective switch, capabilities that underpin everything from coherent communications to quantum information protocols that must synchronize photons arriving from different sources.

A second, more speculative thread reaches into fundamental physics: the search for ultralight dark matter. Cosmological and astrophysical evidence overwhelmingly indicates that most of the matter in the universe is invisible, interacting with ordinary matter only through gravity, yet its identity remains one of the deepest open questions in science. Among the many candidate particles proposed over the decades, ultralight bosons occupy a particularly tantalizing corner of parameter space. If they exist, they could behave less like particles and more like a faint, oscillating classical field that permeates everything, potentially exerting periodic forces on matter at extremely well-defined frequencies. Detecting such signals requires sensors of extraordinary sensitivity to vanishingly weak, narrow-band forces, and precision mechanical resonators coupled to optical readout are among the most promising architectures. Renninger’s project aims to evaluate and extend this sensitivity, potentially giving researchers a new class of instruments for listening to the faintest gravitational whispers of the dark sector.

The program also promises new tools for interrogating the materials themselves. Defects in crystals, atomic-scale imperfections that disrupt an otherwise regular lattice, play a decisive role in semiconductor technology, where they can either ruin a device or, when engineered deliberately, serve as qubits, single-photon sources, or sensors. Mapping where these defects sit, how they lose energy, and how they interact with their surroundings is notoriously difficult. Renninger envisions using light to control and measure mechanical motion as a way to reveal this hidden landscape, essentially turning acoustic and optical probes into microscopes for energy loss and imperfection. Such techniques could benefit the semiconductor industry, where understanding defect behavior is central to manufacturing, as well as the quantum community, where the coherence of spin qubits often hinges on the defect environment.

Perhaps the most conceptually ambitious aim is to build experimental platforms for testing how large mechanical systems behave near the limits of quantum physics. Quantum mechanics was developed to describe atoms and photons, yet there is no agreed-upon reason why it should fail at larger scales, and no consensus on where, if ever, the quantum-to-classical transition occurs. Massive mechanical oscillators, because they couple to so many environmental degrees of freedom, offer a clean testing ground. By cooling such oscillators toward their quantum ground state and then driving them with light, researchers can ask whether superposition and entanglement persist in objects containing trillions of atoms. Renninger’s stated ambition to broaden how researchers use light to control and measure motion in systems that are currently hard to reach speaks directly to this question, extending optomechanical techniques to platforms where they have not previously been practical.

Beyond the technical program, the Moore Foundation’s Experimental Physics Investigators Initiative is structured to amplify individual awards through collective benefit. The 21 new investigators are brought together as a cohort, with support for exchanging ideas, developing new collaborations, and investing in mentoring and professional development. For mid-career scientists, this model of flexible funding is often described as room to take risks, and it reflects a philosophy that the most transformative experiments frequently begin as questions too open-ended to survive a conventional proposal cycle. Renninger expressed gratitude for the foundation’s support of his research program, noting that his lab hopes to produce better tools for optical signal processing, new ways to map hidden defects and energy loss inside materials, and experimental platforms for probing quantum behavior in mechanical systems. The full list of 2026 investigators is available on the Moore Foundation website, and for the field of optomechanics, the award signals that the marriage of light and sound is now regarded as one of experimental physics’ most fertile frontiers.

Subject of Research: Cavity optomechanics: coupling photons and phonons for quantum sensing, signal processing, and fundamental physics

Article Title: Pairing light and sound to explore new frontiers in physics

Article References: Pairing light and sound to explore new frontiers in physics. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: optomechanics, photons, phonons, quantum physics, surface acoustic waves, dark matter, Moore Foundation, University of Rochester, signal processing, crystal defects, quantum sensing, experimental physics