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News 2026년 09월 11일 금요일

Successful Completion of 2026 UNIST Pioneer Symposium

UNIST brought together leading researchers in batteries, nanoscience, and energy chemistry for the second UNIST Pioneer Symposium, held from September 8 to 9, 2026. Hosted by the School of Energy and Chemical Engineering, the two-day symposium welcomed nearly 400 participants from academia, industry, and research institutions. Building on last year's focus on electrochemistry, the 2026 program broadened its scope to next-generation battery materials and systems, electrocatalysis, energy storage and conversion, and related areas of materials science. Featured speakers included Professor Peidong Yang at the University of California, Berkeley, and Professor Arumugam Manthiram at the University of Texas at Austin, internationally recognized for their work in nanoscience and battery materials, respectively. Professor Manthiram delivered the Nobel Lecture on behalf of John B. Goodenough following his 2029 Nobel Prize in Chemistry. The program also featured researchers working at the forefront of all-solid-state batteries, carbon dioxide conversion, and other areas of materials and energy science. Talks and panel discussions were complemented by poster sessions showcasing research by students and early-career scientists. Industry participation expanded this year, with Sa Heum Kim, Executive Vice President at SK On, who oversees next-generation battery research, joining representatives from major companies. The symposium was also supported by Samsung SDI, the Royal Society of Chemistry (RSC), Wiley, and other academic and research organizations. The Pioneer Symposium was launched in November 2025 with a focus on innovation in electrochemistry. The inaugural meeting featured Stanford University Professor Yi Cui and research spanning battery energy storage, electrocatalysis for hydrogen production, and AI-assisted materials development. This year's program broadened that scope while strengthening exchanges among researchers from academia and industry. Building on UNIST's research in advanced technologies, Ulsan is preparing for new opportunities in future mobility and secondary batteries,” said UNIST President Chong Rae Park. “I hope this symposium will foster meaningful scientific exchange and lead to new ideas and collaborations.”

Research 2026년 09월 08일 화요일

Perovskite Solar Cells Hold Up Under Extreme Temperature Swings

Summary The advent of self-assembled monolayer (SAM)-based hole-selective layers (HSLs) has revolutionized inverted perovskite solar cells (i-PSCs) by enabling record efficiencies, but they are constrained by incomplete surface coverage and interfacial heterogeneity. We devise topology-governed SAMs featuring isomeric linker patterns (LY-ortho [o], LY-meta [m], and LY-para [p]) and uncover the principle that conformational ordering dictates surface coverage and interfacial interaction coupling with perovskite. The topology-optimized LY-m forms a homogeneously dense, stable HSL with superior energy alignment and interfacial passivation. Devices incorporating LY-m achieve a record-high open-circuit voltage of 1.231 V, accompanied by an efficiency of 26.39% (certified 26.37%), while maintaining robust operational stability and scalability. Beyond laboratory metrics, LY-m-based devices withstand −100°C to 100°C thermal cycling with only ∼9% loss, far exceeding the operational limits of state-of-the-art commercial SAMs, while maintaining over 80% of their initial performance at 85°C (T80 ≅ 2,000 h). This work resolves the long-standing role of linker topology and paves the way for extreme-environment-resilient and scalable perovskite photovoltaics. Temperature swings are a major challenge for perovskite solar cells (PSCs), particularly in environments such as space, where materials may repeatedly move between extreme cold and heat. Led by Professors Changduk Yang and Seungjae Shin of the Department of Energy and Chemical Engineering and Professor Myung Hoon Song of the Department of Materials Science and Engineering at UNIST, the team developed perovskite solar cells that withstand such extremes by stabilizing a critical molecular interface. The cells retained about 91% of their initial efficiency after cycling between −100°C and +100°C, with a certified power-conversion efficiency of 26.37%. The key to this advancement is a self-assembled monolayer (SAM), a molecule-thin layer that helps move electrical charges between the electrode and the perovskite absorber. Under severe thermal stress, SAM molecules can shift or cluster, disrupting the interface and degrading performance. The team addressed this problem by changing where the molecular components of the SAM connect. They synthesized three versions with different linker positions and found that LY-m adopted a tilted orientation, allowing its molecules to pack densely and uniformly on the electrode. This arrangement also suppresses the molecular reorganization that can occur under large temperature swings. In thermal-cycling tests, LY-m cells were held alternately at −100°C and +100°C for 30 minutes at each temperature over 16 cycles. They remained operational with only about a 9% loss in efficiency, while cells using a commercial SAM failed under the same conditions. LY-m cells also reached a peak efficiency of 26.39%, with a certified efficiency of 26.37% and an open-circuit voltage of 1.231 V. At 85°C, they maintained more than 80% of their initial performance for approximately 2,000 hours. The approach also performed well at larger scales: a 1 cm² cell achieved 23.25% efficiency, while a 3 × 1 cm² mini-module reached 21.20%. “By changing only the position of the molecular connection, we were able to control how the molecules pack on the electrode,” said Professor Yang. “The resulting interface combines high efficiency with thermal stability, offering a promising route toward perovskite photovoltaics for environments with extreme temperature variations.” The study has been participated by Seunglok Lee and Jeewon Park of the Department of Energy and Chemical Engineering and Jingyu Yang of the Department of Materials Science and Engineering at UNIST, as co-first authors of the study. Published in Joule on August 3, the study has been supported by the Nano & Material Technology Development Program through the National Research Foundation (NRF) of Korea and the InnoCORE program of the Ministry of Science and ICT (MSIT). Journal Reference Seunglok Lee, Jinkyu Yang, Jeewon Park, et al., "Topology-governed self-assembled monolayers enable perovskite solar cells stable at −100°C to +100°C," Joule , (2026).

Research 2026년 09월 01일 화요일

Rethinking What Matters

《Editor's Note: What does it take to make something work better? The answer may be to pare back what is unnecessary, rethink how existing parts are arranged, find another route around a constraint, or widen the frame of the problem itself. This month's UNIST research offers answers in many forms—from leaner AI systems and redesigned material structures to an unexpected route for electron transfer and a broader view of cancer drug resistance. Some of those answers run counter to what we might expect. 》 Less Can Be Enough “How much does AI really need?” AI has spent years scaling up. But recent UNIST research asks a different question—how much can be taken away while keeping what matters? At ACL 2026, researchers introduced GMoE, an architecture that shares experts across layers rather than repeatedly storing similar ones. It cut model parameters by about 63 percent, from 549 million to 204 million, while average accuracy remained virtually unchanged—39.51 percent, compared with 39.55 percent for the baseline. The next target was data. Presented at ICML 2026, CSOR removes redundant training images while preserving meaningful variation within each identity. Using roughly half the original dataset, models retained more than 95 percent of full-data performance in re-identification (ReID) tasks. A third study moved to hardware. An automated design framework for logic-in-memory (LiM) computing optimized the placement and routing of computing elements, cutting computation cycles by 19.6 percent under area constraints. ■ GMoE—Expert Sharing for Smaller AI Models (ACL 2026) ■ CSOR—Less Training Data for ReID AI (ICML 2026 ) ■ LiM—Smarter Chip Design (IEEE TCAD) Arrangement Matters “In materials, where can matter as much as what.” More iron, less corrosion. Iron (Fe) is one of magnesium's most damaging impurities, yet UNIST researchers produced a Mg alloy containing more than six times as much Fe as ultra-high-purity Mg—and it still corroded more slowly. Instead of removing the impurity, the team added scandium (Sc) to form core–shell particles that isolate Fe-rich regions from the surrounding Mg. The corrosion rate fell from 22.2 to 0.38 millimeters per year, nearly a 60-fold reduction. At the molecular scale, thermal annealing changed the packing of an organic semiconductor, more than tripling its absorption dissymmetry and even reversing its preferred handedness of circularly polarized light (CPL). The resulting near-infrared (NIR) photodetector achieved a dissymmetry factor of 0.1 at 850 nanometers. The scale shifts again in perovskite solar cells (PSCs). The same high-efficiency formulation crystallized differently depending on the buried interface beneath it. Tailoring the chloride chemistry to the inverted architecture produced a device with 26.3 percent efficiency and a fill factor (FF) of up to 86.8 percent. ■ Mg Alloy—Shielding Fe to Slow Corrosion (Science Advances) ■ NIR Photodetector—Turning Molecular Packing (Advanced Science) ■ PSCs—Why Architecture Changes Performance (Joule) Another Way Through “How spin opens a new route for electron transfer.” Conventional energetics suggested that electron transfer should be unfavorable. Yet in manganese (Mn)-doped quantum dots (QDs), spin-exchange interactions enabled transfer more than ten times faster than in undoped QDs. The mechanism could help capture energetic hot electrons before their excess energy dissipates—a longstanding challenge in photocatalysis and solar-energy conversion. ■ Hot Electrons—Spin-Enabled Transfer (Nature Communications) Beyond the Tumor “The cells helping cancer resist treatment.” Some of the cells helping breast cancer resist treatment are not part of the tumor at all. UNIST researchers found that nearby fat cells can become cancer-associated adipocytes, which release complement factor D and activate survival signaling in cancer cells. In mouse models, disrupting this TRAP1-driven communication improved the response to chemotherapy, pointing to surrounding adipocytes as potential therapeutic targets alongside the tumor itself. ■ Breast Cancer—How Nearby Fat Cells Drive Drug Resistance (STTT) Explore the latest issue and follow 『The UNIST Brief』 on LinkedIn to stay updated. Subscribe via LinkedIn

News 2026년 08월 31일 월요일

UNIST Brings New Perspectives to Battery Research and Development

More than 300 battery researchers and industry experts gathered at UNIST to examine how artificial intelligence, changing research priorities, and closer ties with industry are shaping battery research and development. Hosted by the School of Energy and Chemical Engineering, the 5th Forum on Recent Trends in Secondary Battery Research and Development brought together participants from universities, companies, and research institutes across Korea. Held from August 27 and 28, this year's program focused on three themes—career development for early-career researchers, the use of AI in battery R&D and manufacturing, and the relationship between academic research and industrial needs. Each session combined presentations with open discussion, allowing participants to compare perspectives across academia and industry. The first session examined how early-career researchers can establish independent research directions and navigate the early stages of an academic career. Haeseong Jang of Chung-Ang University, Minkyung Kim of Kwangwoon University, and Moonseok Chae of Pukyong National University shared their experiences, followed by a discussion led by Mina Lee of POSTECH. The AI-Battery session explored where artificial intelligence can contribute to battery development and manufacturing—and what is needed to put those tools into practice. Inchul Park of DGIST and KyuJung Jun of Korea University presented approaches to AI-enabled battery research, while a discussion led by Dong-Hwa Seo of KAIST addressed data use, implementation, and remaining technical challenges. The final session turned to the relationship between research and industry. Sang-Min Lee of POSTECH and Kyung-Min Jeong of UNIST drew on their development experience to discuss the priorities facing battery researchers. Professor Won-Jin Kwak of UNIST then led a discussion on how universities, companies, and research institutes—with different research goals and timelines—can work more effectively together. The exchange extended beyond the sessions. Sponsors, Ulsan Technopark, and regional companies presented their technologies at exhibition booths, and participants visited Ulsan Technopark on August 28 to see electrode and cell manufacturing, diagnostics, and recycling facilities at an industrial scale. “Battery research increasingly brings together materials innovation, artificial intelligence, and the needs of industry,” said Professor Kwak, who organized the forum. “We hope this meeting will provide a starting point for new research collaborations by connecting early-career researchers with colleagues across academia and industry.” Launched at UNIST in 2022, the forum has since rotated among UNIST, POSTECH, and DGIST. Last year's meeting focused on cathode and anode materials, next-generation batteries, and recycling. This year's program broadened that scope to consider not only battery technologies themselves, but also the researchers, digital tools, and partnerships behind their development.

Research 2026년 08월 28일 금요일

New X-Ray Mapping Technique Enables Non-Destructive Analysis of Large-Area Perovskite Solar Cells

Abstract Scaling perovskite solar cells (PSCs) into large-area modules requires precise control of structural uniformity and mechanical integrity. However, scalable deposition often introduces mesoscale heterogeneities, including grain-orientation disorder and lattice-strain gradients, which limit efficiency and stability. Here, we report an intact-film orthogonal two-dimensional X-ray diffraction mapping (2DXDM) technique that enables full-field, quantitative crystallographic analysis of large-area perovskite films without physical sectioning. The method resolves spatial variations in crystallinity, orientation coherence, and lattice strain across complete modules and is validated against conventional sectioned analyzes such as grazing-incidence wide-angle X-ray diffraction (GI-WAXD) and X-ray diffraction (XRD). Using this approach, we compare static spin-coating (SSC) and dynamic spin-casting (DSC). DSC yields more homogeneous films with relaxed lattice stress and controlled solvate evolution, thereby reducing edge defects. As a result, DSC-based modules achieve 23.0% efficiency (22.7% certified) over 86.4 cm2 and retain over 80% of their initial efficiency after 1,000 h of operation. Perovskite solar cells (PSCs) have reached impressive efficiencies at laboratory scale, but maintaining that performance in larger modules remains challenging. As the films grow larger, differences in crystal orientation and internal strain can develop across the surface, creating defects that reduce efficiency and long-term stability. A research team led by Professors Dong-Seok Kim and Jin Young Kim of the School of Energy and Chemical Engineering and Professor Tae Joo Shin of the Graduate School of Semiconductor Materials and Devices Engineering at UNIST, together with Dr. Yun Seop Shin of the Korea Research Institute of Chemical Technology (KRICT), has developed an X-ray technique that maps these structural variations across an intact perovskite film. Called two-dimensional X-ray diffraction mapping (2DXDM), the technique shows how crystallinity, crystal orientation, and residual strain vary across an entity film without damaging it. Conventional methods often examine selected regions, provide averaged measurements, or require samples to be cut into sections. PSCs are made by depositing a liquid precursor onto a surface, where it dries and crystallizes into a light-absorbing layer. Across a large area, differences in drying and crystallization can leave the center and edges with different structural properties. The researchers used 2DXDM to compare two methods for forming large-area films. In static spin-coating (SSC), the precursor solution is applied before the substrate is spun, while dynamic spin-casting (DSC) deposits the solution drop by drop as the substrate rotates. The resulting maps showed that DSC produced more homogeneous films, with more consistent crystal orientation and lower residual strain. Additional X-ray measurements linked this improvement to better control over colon drying and crystal formation, which helped reduce structural defects near the edges. The more uniform films also delivered strong performance at module scale. DSC-based modules reached a power conversion efficiency of 23.0% over an active area of 86.4 cm², with a certified efficiency of 22.7%. Encapsulated modules retained more than 80% of their initial efficiency after 1,000 hours under continuous illumination. “Conventional methods make it difficult to see how structure varies across an entire film, and cutting a sample for analysis can alter the strain already present” said Professor Shin. “With 2DXDM, we can examine the full area without damaging the film and identify where structural differences occur.” Professor Dong-Seok Kim added, “For large-area perovskite films, what matters is structural uniformity across the entire surface, not just at a few individual points. By showing how fabrication conditions affect that uniformity, this approach can help guide the development of more efficient large-area modules.” Dong Shin Kim of the Graduate School of Semiconductor Materials and Devices Engineering and Jae Hwi Lee of the School of Energy and Chemical Engineering at UNIST, served as first authors. The research used the UNIST-PAL 6D beamline at the Pohang Accelerator Laboratory. The findings were published online in Joule on July 23, 2026. The research was supported by the Ministry of Science and ICT (MSIT), Ministry of Education (ME), National Research Foundation of Korea (NRF), Ministry of Trade, Industry and Energy (MOTIE), Korea Institute of Energy Technology Evaluation and Planning (KETEP), Korea Institute for Advancement of Technology (KIAT), and Korea Research Institute of Chemical Technology (KRICT). Journal Reference Dongshin Kim, Jaehwi Lee, Dongmin Lee, et al ., “Intact-film orthogonal 2D X-ray diffraction mapping for crystallographic homogeneity evaluation in perovskite solar modules,” Joule , (2026).

Research 2026년 08월 19일 수요일

Study Reveals Why Perovskite Performance Changes Across Solar Cell Designs

Abstract A perovskite precursor solution that delivers power conversion efficiencies (PCEs) exceeding 26% in conventional nip solar cells exhibits severe performance losses when directly applied to inverted pin architectures, revealing that high-efficiency compositions are not inherently transferable. Here, we identify a buried-interface crystallization mismatch, arising from the distinct physicochemical natures of inorganic SnO2 electron-transporting layers and organic self-assembled hole-transporting monolayers (SA-HTLs), as the origin of this divergence. The methylammonium chloride (MACl)-associated intermediate phase, MA2Pb3I8·2DMSO, persists and decomposes with strong underlayer dependence, stabilizing beneficially on SnO2 but impeding crystallization on SA-HTLs. To overcome this limitation, we develop a chloride-origin engineering strategy that decouples chloride functionality from volatile organic ammonium species by incorporating low-solubility lead chloride (PbCl2) with strong Pb–Cl coordination. This enables controlled interfacial desolvation and nucleation on SA-HTLs, suppresses buried defects, and establishes buried-interface crystallization control as a design principle for architecture-convergent, high-efficiency perovskite solar cells. Building a high-performance solar cell takes more than getting the materials right. The same ingredients can produce very different results when the layers are arranged differently—and researchers at UNIST have discovered why. Led by Distinguished Professor Sang Il Seok of the School of Energy and Chemical Engineering at UNIST, the team found that the surface beneath the light-absorbing perovskite layer can determine how well its crystals form. By tailoring the material chemistry to that surface, the researchers developed an inverted perovskite solar cell with a power conversion efficiency of 26.3% and improved stability. PSCs can be built in conventional nip or inverted pin configurations. Both have reached high efficiencies, but formulations optimized for one do not necessarily perform as well in the other. Inverted cells are particularly important for perovskite–silicon tandem solar cells, where they are commonly used as the top cell. The researchers found that this performance gap originates at the buried interface, where the perovskite layer forms on the material beneath it. A formulation that achieved efficiencies above 26% in conventional cells lost much of its performance when transferred directly to an inverted design. The difference came down in part to methylammonium chloride (MACl), an additive used to improve perovskite crystal growth. In conventional cells, an intermediate formed by MACl supports crystallization on the underlying inorganic layer. But on the organic layer used in inverted cells, the intermediate persists longer, disrupting crystal growth and leaving behind voids and defects that can lead to electrical losses. Rather than removing chloride, the team changed how it was introduced. The researchers reduced the amount of MACl and added a small amount of lead chloride (PbCl2), whose stronger interaction with chloride helped control where and when crystals began to form. This produced a cleaner buried interface with fewer defects. With the revised formulation, the inverted cells reached a peak efficiency of 26.3% and a fill factor of up to 86.8%, while also showing improved stability. The results demonstrate that controlling how perovskite crystals form at the underlying surface can help high-performance materials work across different solar-cell designs. “High-efficiency formulations developed for conventional PSCs do not necessarily behave the same way in inverted devices,” said Professor Seok. “By identifying the origin of this performance loss, we established a way to control crystal formation at the buried interface. The findings provide a design direction for developing efficient inverted cells for high-performance perovskite–silicon tandem solar cells.” Their findings have been published online in Joule on July 28, 2026. The study was supported by the National Research Foundation of Korea (NRF). Journal Reference Jongbeom Kim, Nahye Shin, Chaehoon Jeon, et al ., “Buried-interface crystallization limits the transferability of high-efficiency perovskite precursor compositions,” Joule ,(2026).

News 2026년 08월 06일 목요일

UNIST to Host ACS Publications Forum on the Future of Nanoscience

UNIST brought together leading scientific journal editors and early-career researchers on July 31 for the ACS Publications Forum: The Future of Nanoscience , a daylong program focused on emerging research across nanoscience and materials science. Co-hosted by ACS Publications and the UNIST School of Energy and Chemical Engineering, the forum was held under the theme ' ACS Editors' Forum with Early-Career Leaders in South Korea .' The program combined editor sessions, research presentations, panel discussions, and a poster session, creating opportunities for researchers at different career stages to exchange ideas and explore new connections. The forum featured Editor-in-Chief Teri W. Odom of Nano Letters, Editor-in-Chief Xiaodong Chen of ACS Nano, and Editor-in-Chief Suzie Pun of ACS Nano Medicine. Editors from Chemistry of Materials, ACS Nano, and Nano Letters, as well as representatives from ACS Publications, also participated. The afternoon Emerging Scholar Program highlighted research by early-career scientists from UNIST and other universities in Korea. Presentations covered battery chemistry and materials, energy conversion, catalysis, polymer self-assembly, stretchable electronics, optoelectronics, AI sensors, and two-dimensional materials, reflecting the breadth of current research across energy materials, soft matter, and electronics. The program also included a poster session featuring student research. A panel discussion with journal editors provided another opportunity to exchange perspectives on scientific publishing and emerging directions in nanoscience, while networking sessions connected editors, faculty members, and early-career researchers. Organized by Professor Hyun-Wook Lee of the School of Energy and Chemical Engineering at UNIST, the forum was designed to connect established journal editors with emerging researchers and strengthen scientific exchange across the nanoscience community. The event's broader research scope ranged from battery chemistry and energy conversion to stretchable electronics and polymer self-assembly.

Research 2026년 08월 01일 토요일

Beyond the Obvious

《Editor's Note: The biggest scientific advances do not always come from discovering something new. Sometimes, they begin by seeing familiar problems in a new light. This month's stories invite us to look beyond the obvious. Across artificial intelligence, semiconductor materials, nanotechnology, and biomedical science, UNIST researchers examined assumptions, structures, and interactions that can easily go unnoticed—but often determine how a system behaves. Their findings show how a deeper understanding of what is already there can open new directions for discovery.》 Questioning Assumptions “The first answer is not always the right one.” Scientific discovery often begins by asking whether the original question was complete. Several AI studies featured this month did just that, revisiting assumptions about how machines learn, forget, reason, and communicate. In federated learning, researchers found that differences in camera viewpoints—not only privacy constraints or data distribution—can significantly affect how well AI models learn together. Another team showed that machine unlearning involves more than simply removing data: forgetting can unintentionally alter knowledge that should remain. Elsewhere, a new communication framework showed that effective cooperation among AI agents depends less on exchanging more information than on exchanging the right information. Other studies reconsidered how AI systems reason across multiple views of the same scene and explored how quantum computing could reduce the cost of training robust AI models. Different problems, but a common starting point: questioning the assumptions built into them. Together, these studies point to a simple lesson: better answers often begin with better questions. ■ Rethinking Federated Learning: Camera Viewpoints Matter (CVPR 2026) ■ Making AI Forget—Without Losing What Matters (ICML 2026 ) ■ Smarter Communication for Collaborative AI (ICML 2026) ■ Rethinking Multiview Reasoning (ICML 2026) ■ Quantum Algorithm Cuts the Cost of Training Robust AI (ICML 2026) Looking Beneath the Surface “The smallest details often hold the biggest clues.” Across materials science, biology, nanotechnology, and semiconductor engineering, UNIST researchers examined structures and interactions that are easy to miss but can have an outsized influence on how materials, devices, and biological systems behave. In semiconductor research, the spacing between neighboring atoms emerged as a critical factor in controlling material properties and device performance. At the nanoscale, researchers examined how the surface chemistry of quantum dots influences their behavior in imaging. Another study turned to microscopic wrinkles, showing how their geometry can reshape optical properties. The same attention to underlying mechanisms extended to biology, where researchers found that familiar forms of cell death do not always follow the pathways scientists expect. Together, these studies show how seemingly minor details—from atomic spacing and surface chemistry to microscopic geometry and cellular mechanisms—can fundamentally change our understanding of a system. Sometimes, the most consequential discoveries begin with something that was there all along, waiting to be examined more closely. ■ Atomic Precision for Better Semiconductors (Chem. Mater., 2026) ■ A New Perspective on QD Imaging (Nano Converg., 2026) ■ Wrinkles that Reshape Photonics (Adv. Funct. Mater., 2026) ■ When Cell Death Follows Different Rules (Cell Death Differ., 2026) Across very different fields, these studies share a common instinct: question the assumption, examine the detail, and look again. What appears familiar can still hold unanswered questions. Looking beyond the obvious is not simply how these discoveries were made. It is how scientific discovery moves forward. Explore the latest issue and follow 『The UNIST Brief』 on LinkedIn to stay updated. Subscribe via LinkedIn

Research 2026년 07월 23일 목요일

New Surface Design Makes QDs More Reliable for Single-Molecule Imaging

Abstract Quantum dots (QDs) are fluorescent nanoparticles widely used for single-molecule imaging because of their exceptional brightness and photostability. However, the impact of QD surface chemistry on biomolecular interactions has not been systematically investigated. Here, we report that commercial QDs unexpectedly destabilize protein-DNA complexes by inducing protein dissociation from DNA. Using the human nucleotide excision repair protein, xeroderma pigmentosum complementation group A (XPA) as a model system, we demonstrate that antibody-conjugated QDs promote dissociation of XPA from DNA substrates, independently of sizes and surface modification of QDs, antibody types, epitope tags, buffer conditions, or DNA structures. We find that polyethylene glycol (PEG), a common polymer coating on QD surfaces, is the primary factor responsible for this effect. To tackle this problem, we engineered QDs with precisely controlled surface polymer compositions. By systematically changing the ratio of anchoring, hydrophilic, and PEG-based functional groups, we find that reducing PEG density below a critical threshold effectively suppresses protein dissociation while maintaining excellent colloidal stability and brightness. Furthermore, antibodies conjugated via click chemistry between azide groups and DBCO enabled specific labeling of XPA without perturbing the DNA binding activity. Using these optimized QDs, we conducted single-molecule DNA curtain assays to visualize XPA-DNA interactions. QD-labeled XPA exhibits one-dimensional diffusion with frequent pausing on undamaged DNA. DNA curtain assays revealed that XPA preferentially binds DNA bubbles and searches for bubble structures through both one-dimensional diffusion and three-dimensional collision. Quantitative analysis showed that three-dimensional collision is the dominant pathway for bubble recognition. Taken together, our results uncover a previously unrecognized limitation of PEG-coated QDs in single-molecule studies and provide an improved surface-engineering strategy to preserve native protein-DNA interactions. Newly engineered QDs establish robust platforms for accurate single-molecule visualization of biomolecular processes. Quantum dots (QDs) are widely used as fluorescent probes for single-molecule imaging because they are brighter and more photostable than conventional fluorescent dyes. Researchers at UNIST have now discovered that the surface chemistry of many commercially available QDs can unintentionally disrupt the protein–DNA interactions they are intended to observe. The team also established a surface-engineering strategy that minimizes this interference without compromising their imaging performance. Led by Professor Jaeil Lee of the Department of Biological Sciences and Professor Jongnam Park of the School of Energy and Chemical Engineering, the researchers identified polyethylene glycol (PEG), a polymer widely used to coat commercial QDs, as the source of the interference. When PEG occupied too great a proportion of the particle surface, protein–DNA interactions became destabilized, revealing a previously unrecognized limitation of a widely used imaging probe. The finding arose while the team was investigating xeroderma pigmentosum complementation group A (XPA), a DNA repair protein involved in nucleotide excision repair. As the concentration of commercially available QDs increased, XPA unexpectedly dissociated from DNA. The same behavior persisted regardless of quantum dot size, antibody type, surface modification, buffer conditions, or DNA structure, indicating that the disruption originated from the probe itself rather than the biological system. To address this limitation, the researchers systematically redesigned the quantum dot surface by adjusting the proportions of anchoring, hydrophilic, and PEG-derived functional groups. They found that reducing the PEG-derived surface composition below approximately 7% preserved native protein–DNA interactions while maintaining the brightness and colloidal stability required for single-molecule imaging. Using the redesigned QDs, the researchers visualized how XPA searches for sites of DNA damage without perturbing its natural behavior. Single-molecule DNA curtain experiments showed that XPA locates DNA bubble structures through both one-dimensional diffusion along DNA and three-dimensional collisions from solution. Quantitative analysis revealed that three-dimensional collisions are the dominant pathway for recognizing damaged DNA under physiologically relevant protein concentrations. “Commercial quantum dots have long been regarded as passive fluorescent probes,” said Professor Lee. "Our study shows that their surface chemistry can directly influence the molecular interactions being observed. By identifying the source of this interference, we established a practical strategy for preserving native protein–DNA interactions during single-molecule imaging." Professor Park added, "Careful control of surface polymer composition allowed us to reduce molecular interference without compromising brightness or colloidal stability. We expect these design principles to support the development of more reliable nanoparticle-based probes for biological imaging." The study also included contributions from Youngseo Kim of the Department of Biological Sciences and Hyerim Kim of the Department of Energy and Chemical Engineering at UNIST. The findings were published online in Nano Convergence on June 3, 2026. The research was supported by the National Research Foundation of Korea (NRF), the Institute for Basic Science (IBS), and the Ministry of Trade, Industry and Energy (MOTIE). Journal Reference Youngseo Kim, Hyerim Kim, Munryul Choi, et al ., "Engineering quantum dot surfaces to preserve protein-DNA interactions for single-molecule visualization," Nano Converg ., (2026).

Research 2026년 06월 18일 목요일

Game-Changing Interface Coating Enables Scalable, High-Efficiency Perovskite/Silicon Solar Cells

Abstract Self-assembled monolayers (SAMs) represent an effective strategy for the development of perovskite solar cells (PSCs). High-performance PSCs are typically fabricated in an inert atmosphere because ambient moisture disrupts phosphonic-acid SAMs on transparent conductive oxides, leading to surface inhomogeneity and direct exposure of the transparent conductive oxide. However, this dependence on glovebox fabrication constraints scalability and cost-effective manufacturing. Here we present a ternary self-assembled molecular contact comprising glycerol dimethacrylate and 1-acetylguanidine that serves as a process-tolerant hole-selective contact. Glycerol dimethacrylate acts as a cosolvent during SAM deposition to improve film uniformity and is subsequently transformed into a hydrophilic binary network upon mild thermal curing, firmly anchoring the SAM to the substrate, whereas 1-acetylguanidine is incorporated to further suppress interfacial defects. Wide-bandgap PSCs fabricated in ambient conditions achieve a power conversion efficiency of 21.20% (1.00 cm2), with an open-circuit voltage of 1.28 V. When implemented in monolithic perovskite/silicon tandems, cells achieve a power conversion efficiency of 31.72% (certified 31.36%) and 32.60% for fabrication in ambient and inert conditions, respectively. These findings demonstrate that our tailored hole-selective contact provides a robust and process-tolerant interfacial engineering approach for high-efficiency perovskite and tandem photovoltaics manufactured under ambient conditions. UNIST, in collaboration with King Abdullah University of Science and Technology (KAUST), has developed a groundbreaking coating that unlocks large-scale, ambient-condition production of high-performance perovskite/silicon tandem solar cells. Led by Distinguished Professor Sang Il Seok of the School of Energy and Chemical Engineering and Professor Kyoung Jin Choi of the Department of Materials Science and Engineering, the team engineered a three-component interface layer that ensures uniform coverage and reduces defects during fabrication. This innovation allows the production of tandem cells outside of costly, sealed environments—an essential step toward commercialization. The resulting devices achieved a certified efficiency of 31.36%, with peak performance reaching 31.72%. Remarkably, they maintained over 92% of their initial efficiency after 600 hours in oxygen-rich, high-temperature conditions, and over 90% after 1,000 hours under continuous illumination—all without encapsulation. This technology not only delivers record efficiencies but also simplifies manufacturing, drastically reducing costs and enabling large-area production in standard environments. It paves the way for affordable, high-efficiency solar solutions that can be deployed at scale. The research team includes Gwisu Kim and Young Im Noh from UNIST, and Adi Prasetio from KAUST as first co-authors. The corresponding authors are Professors Sang Il Seok and Kyoung Jin Choi from UNIST, and Professor Stefaan De Wolf from KAUST. Contributions also came from researchers from the Chinese University of Hong Kong, Shenzhen (CUHKSZ) and Forschungszentrum Jülich GmbH (FZJ) in Germany. Professor Choi states, “Our findings align with the K-Moonshot Project, a national initiative focused on developing ultra-high-efficiency multi-junction solar cells, which brings us closer to realizing practical and affordable solar energy.” Professor Seok adds, “Demonstrating stability and high efficiency in open air indicates that the technology is ready for industrial-scale production.” Published in Nature Photonics on June 1, this breakthrough was supported by Hyundai Motor Company, the National Research Foundation of Korea (NRF), the Ministry of Science, and ICT (MSIT), the Korea Energy Technology Evaluation and Planning Agency (KETEP), and the Ministry of Trade, Industry and Energy (MOTIE). Journal Reference Gwisu Kim, Adi Prasetio, Young Im Noh, et al., “Ternary self-assembled molecular contact for ambient-processed perovskite/silicon tandem solar cells,” Nat. Photon. , (2026).

Research 2026년 06월 17일 수요일

Roll-to-Roll Manufacturing of Ruthenium-Loaded Carbon Fiber Electrodes for Efficient Hydrogen Production

Abstract Carbon fiber-based electrocatalysts offer significant advantages over conventional powder catalysts, including enhanced active site exposure, superior conductivity, faster reaction rates, lower costs, and improved stability under harsh conditions. In this study, we introduce a rapid and scalable method for spinning carbon-supported metal catalysts into their fibrous forms to achieve uniform catalyst structures that enable roll-to-roll manufacturing. We demonstrate uniform ruthenium (Ru) nanoparticle-loaded carbon fibers by spinning polyacrylonitrile (PAN)-Ru phenanthroline complexes and annealing at 1200 °C for the optimum Ru particle size distribution. We found that the interaction of the Ru complex with the nitrile (−C≡N) group of PAN enabled rheological control and ensured monodisperse Ru confinement. Our investigation of the mechanism details the microstructural evolution during carbonization and oxygen plasma treatment, showing exceptional enhancement in the performance of Ru-embedded carbon fabric electrocatalysts. Ultimately, our rheology-driven spinning protocol bridges the gap between laboratory-scale synthesis and industrial manufacturing of fabric electrocatalysts, providing a versatile platform for nanoconfinement that offers critical insights into the structural evolution of metal–polymer nanocomposites for next-generation energy applications. A research team affiliated with UNIST has introduced a scalable process to produce long-lasting, fiber-shaped electrodes for water electrolysis, paving the way for large-scale hydrogen production. Professor Han Gi Chae of the Department of Materials Science and Engineering and Professor Jong-Beom Baek of the School of Energy and Chemical Engineering collaborated with Professor Cafer T. Yavuz at King Abdullah University of Science and Technology (KAUST). Traditional electrodes rely on coating catalysts onto conductive substrates, often using binders that block active surfaces. In contrast, these new fibers act as both support and conductor, allowing water and electrolytes to flow freely and hydrogen to escape efficiently. Central to this method is the embedding of ruthenium particles within the polymer fibers, resulting in improved catalyst dispersion and durability. By mixing a viscous polymer-Ru precursor and extruding it through a nozzle, the team produced continuous fibers. When heat-treated at 1200°C, these fibers develop a uniform distribution of catalytic nanoparticles inside and on the surface, preventing clumping and ensuring consistent activity. Achieving this required precise control over the interaction between the Ru precursor and the polymer. The researchers optimized the conditions to maintain even dispersion during fiber formation. They further enhanced the surface exposure of catalytic sites through oxygen plasma treatment, significantly improving performance and stability. Testing showed that these fibers could operate continuously for more than 170 hours at a high current density of 500 mA/cm² without degradation. Their catalytic activity surpassed that of conventional platinum electrodes, highlighting their potential for practical applications. The study was primarily led by Dr. Ga-Hyeun Lee from UNIST and Professor Seok-Jin Kim from KAUST, who served as the first authors, with researcher Inkyung Baek contributing as a co-author. This research offers new insights into the microstructural evolution of metal-polymer nanocomposites and demonstrates a scalable approach to fabricating fiber electrodes for efficient hydrogen production. Professor Chae noted, “Embedding metal catalysts uniformly within carbon fibers enhances electrode stability. This technique could extend beyond water electrolysis to other catalytic systems where durability and uniform reactivity are crucial.” The research was published in ACS Nano (Impact Factor: 16.1, Cite Score: 24.2)Impact Factor: 16.1, Cite Score: 24.2) on May 7, and supported by the Ministry of Science and ICT (MSIT), the Ministry of Education (MOE), and the National Research Foundation of Korea (NRF). Journal Reference Ga-Hyeun Lee, Seok-Jin Kim, Jung-Eun Lee , et al., “Rheological Pathways to a Scalable Ruthenium Nuclei-Anchored Carbon Fiber Catalyst,” ACS Nano, (2026).

Research 2026년 05월 27일 수요일

New Research Reveals High-Performance Organic Solar Cells Surpassing AI Predictions

Abstract Descriptor-based artificial intelligence (AI) has emerged as a paradigm for molecular design in organic solar cells (OSCs); However, it inherently overlooks collective effects governed by bond hybridization, intermolecular coupling, and aggregation thermodynamics. Such effects are encoded at the solution stage, where pre-aggregation of photoactive materials dictates nucleation pathways, phase separation, and molecular ordering during film formation. Herein, we introduce a YBOV non-fullerene acceptor featuring sp2-hybridized branched side chains that exhibit an unprecedentedly strong solution-state pre-aggregation propensity. This behavior translates into highly ordered solid films with a densely packed crystalline microstructure, enabled by a thermodynamically stabilized core–terminal dimer. As a result, incorporation of YBOV into OSCs not only outperforms the benchmark L8-BO-based device, but also confers an effective nucleation seeding-agent function across diverse host OSC platforms, delivering efficiencies of up to 19.67% via green-solvent processing by alleviating the intrinsic current–voltage trade-off. Machine-learning predictions largely match experimental photovoltaic parameters with a slight upward bias, except for open-circuit voltage, which exhibits anomalous behavior driven by pre-aggregation–driven seeding effects beyond descriptor-based AI. This work establishes sp2-hybridized branched side chains as a new molecular design principle, introducing pre-aggregation-enabled seeding effects beyond AI prediction and providing a universal strategy for high-performance OSCs. Researchers from UNIST and Sungkyunkwan University have created a new type of organic solar cell (OSC) that outperforms existing predictions and highlights a hidden factor in device performance. The secret lies in how molecules clump together in solution—a phenomenon that traditional AI models overlook. Professor Changduk Yang from the School of Energy and Chemical Engineering, in collaboration with Professor Doo-Hyun Ko from Sungkyunkwan University, reported a new OSC with a power conversion efficiency (PEC) of 19.67% through a clean, environmentally friendly process. OSCs are lightweight, flexible, and capable of covering large surfaces. They can be integrated into building facades, windows, and wearable devices. The manufacturing process involves dissolving organic materials in solvents and coating them onto substrates—an approach that's simple and scalable. The researchers designed a new molecule, named YBOV, with branched side chains that promote strong pre-aggregation in solution. This aggregation acts like a seed during film formation, guiding molecules to pack more orderly. The result is a crystalline, densely packed active layer that improves charge flow and boosts efficiency. Notably, devices made with YBOV achieved high performance even when produced with eco-friendly ortho-xylene solvent, avoiding toxic chlorinated options. YBOV also proved versatile. When added to different donor materials or used as an acceptor in various blends, it consistently increased device efficiency. Its aggregation behavior enhances performance across a range of formulations. However, this clustering effect escapes prediction by standard AI models. When trained on 750 device measurements, the models underestimated the open-circuit voltage for YBOV-based cells. This shows that AI, which predicts based on molecular structure alone, cannot fully capture the collective behaviors that influence real-world performance. “Our work introduces a new design principle,” said the research team. “It considers how molecules behave in solution—something AI cannot currently predict. Combining this insight with eco-friendly processing opens new paths for commercializing high-performance, sustainable organic solar cells.” Supported by the National Research Foundation of Korea (NRF) and the InnoCore program of the Ministry of Science and ICT (MSIT), the study involved Seokhwan Jeong, Donghoo Won, and Zhe Sun from UNIST who contributed equally. The findings of this research were published in Advanced Energy Materials on April 20, 2026. Journal Reference Seokhwan Jeong, Donghoo Won, Zhe Sun, et al ., “Beyond Descriptor-Based AI Design: Sp2-Hybridized Branched Side Chains Enable Pre-Aggregation–Driven Seeding Effects in Green-Solvent-Processed Organic Solar Cells,” Adv. Energy Mater., (2026).