A new study entitled “Alloy Engineering of Excitonic Properties in TMD Monolayers” has been published in Physical Review Materials and selected as an Editor's Suggestion, highlighting the scientific significance and interest of the work.

The study is the result of an international research collaboration led by the Institute of Electronic Structure and Laser (IESL) of the Foundation for Research and Technology – Hellas (FORTH), Greece, in collaboration with INSA/CNRS (France), the National Institute for Materials Science (NIMS, Japan), the University of Chemistry and Technology Prague (Czech Republic), and the Beijing Institute of Technology (China).

Changing the atomic composition of a semiconductor offers a powerful way to tailor its properties. This study explores atomically thin alloys of molybdenum, sulfur, and selenium by probing their excitons, Coulomb-bound electron-hole pairs. By gradually replacing selenium with sulfur, the study reveals how alloying modifies exciton emission energies, atomic lattice vibrations, spin-orbit coupling and polarization of emitted light. Combining complementary optical spectroscopy techniques with first-principles calculations, the work provides a comprehensive understanding of how alloy composition influences excitonic behavior and its connection to electronic, vibrational, and spin-valley properties.

Reference: Katsipoulaki, E., Smiri, A., Spiliotakis, P., Mourzidis, K., Katrisioti, D., Taniguchi, T., ... & Paradisanos, I. (2026). Alloy engineering of excitonic properties in TMD monolayers. Physical Review Materials, 10, 104010. doi: https://journals.aps.org/prmaterials/abstract/10.1103/m7kc-8q5v

Latest work from FORTH’s QMM Lab explores a fundamental question in condensed matter physics: what drives superconductivity—enabling materials to carry electricity without resistance—and, in particular, what controls its emergence at relatively high temperatures in iron-based materials? The study shows that simply increasing the separation between their conducting layers is not sufficient; instead, molecular insertion modifies how electrons are transferred and distributed within these quantum materials, providing a route to tuning superconductivity.

Revealing these microscopic changes was made possible by the unique brightness and sensitivity of synchrotron X-rays, combining high-resolution X-ray diffraction with synchrotron Mössbauer spectroscopy to probe both the material’s atomic-scale structure and the local electronic environment of iron. Led by Dr. Alexandros Lappas the research brings together expertise from the IESL- Foundation for Research and Technology–Hellas (FORTH) and the Department of Materials Science and Engineering at University of Crete in Greece, together with the European Synchrotron Radiation Facility (ESRF) in France. The study was driven by PhD candidate Myrsini Kaitatzi, first author of the resulting publication. The findings provide important experimental evidence that microscopic electronic structure—not structural expansion alone—is central to understanding and ultimately controlling unconventional superconductivity.

Citation: M. Kaitatzi, D. Bessas, S. Yaroslavtsev, D.C. Stoian, and A. Lappas, J. Phys. Chem. Solids 220, 114128 (2027).

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A new study published in Nano Letters highlights the strong international character of collaborative research in the field of two-dimensional materials and van der Waals heterostructures. The work brings together researchers from several leading institutions across Europe and Japan, including the Institute of Electronic Structure and Laser (IESL) of the Foundation for Research and Technology–Hellas (FORTH), with significant contributions from Danae Katrisioti and Ioannis Paradisanos, as well as Ca’ Foscari University of Venice (Italy), Friedrich Schiller University Jena (Germany), Politecnico di Milano (Italy), the National Institute for Materials Science (NIMS, Japan), and the University of Chemistry and Technology (Czech Republic).

In this study, the researchers demonstrate that stacking monolayer MoSe2 with PdSe2 into a type-I van der Waals heterostructure produces an unusually large enhancement of the A-exciton efficiency, alongside strong quenching of the B-exciton at room temperature. These findings establish that interlayer coupling can be a powerful, straightforward knob for tuning light emission in 2D semiconductors, with promising implications for optoelectronic applications where efficient, controllable emission matters.

Reference: Rozhin, P., Contin, E., Katrisioti, D., Weickhardt, T., Ramzan, M. S., Bertolotti, M., ... & De Fazio, D. (2026). Highly Efficient Exciton Modulation in MoSe₂/PdSe₂ Heterostructures. arXiv preprint arXiv:2605.13211. doi:https://doi.org/10.1021/acs.nanolett.6c02581

Can a natural bioactive molecule become an integral part of the 3D microfabrication process itself?

In this work, published in the journal Advanced Functional Materials, we demonstrate a one-step multiphoton lithography strategy in which curcumin serves not only as a photosensitizer for the fabrication of high-resolution GelMA 3D scaffolds, but also as a bioactive component that endows the resulting structures with advanced functional properties.

The resulting microarchitectures combine precise 3D structuring and cell compatibility with the intrinsic antibacterial and antifouling properties of curcumin.

This approach enables bioactivity to be incorporated directly during the fabrication process, opening new possibilities for advanced biomaterials and tissue engineering applications.

The work was carried out at the Institute of Electronic Structure and Laser (IESL), Foundation for Research and Technology-Hellas (FORTH), by the TERMIm Lab, led by Dr. Anthi Ranella and the NLL Group, led by Dr. Maria Farsari, in collaboration with the group of Prof. Anna Mitraki at the Department of Materials Science and Engineering, University of Crete. Anna Mitraki is also a collaborating faculty member of IESL. The first author is PhD candidate Myrto Charitaki.

Reference: Charitaki, M., Stavrou, M., Apostolidou, C. P., Kabouraki, E., Gray, D., Mitraki, A., ... & Farsari, M. (2026). One‐Step Curcumin‐Mediated Multiphoton Lithography for Bioactive 3D Scaffolds. Advanced Functional Materials, e77532. doi:  https://doi.org/10.1002/adfm.77532

We are proud to announce the publication of a new research study by M. Androulidaki from the IESL–FORTH MRG team, in collaboration with Professor Nikos Chaniotakis from the Department of Chemistry, University of Crete. The study, entitled “Nanocage-mediated enzyme stabilization: The effect of size and charge”, has been published in the prestigious journal Sensors and Actuators B: Chemical.

Abstract

Enzymes are tools utilised in many scientific disciplines. The specific protein employed for each application depends on its specific activity, as well as its physical characteristics, and specifically its operation stability over time. These properties depend not only on the enzyme itself, and on the surrounding environment. The outer boundary, being solvation, cellular crowding, immobilization, or synthetic encapsulation modulates both stability and accessibility by imposing confinement and regulating molecular diffusion. Thus, enzyme stabilization and functional accessibility across disciplines is less about modifying the protein alone, but also on the precise engineering of the spatial and physicochemical properties of its environment. Here, we expand on the theoretical aspect regarding the effect of the protein stabilization effect within solid nanostructures, and its possible effect on the biosensor performance. This work focusses on the effect of not only the size of the nanocavity, but also on the type of solvent utilized, which in turn determines the surface charge. This information is vital in designing the appropriate nanocavity to be used for the immobilization and stabilization of proteins for use in biotechnology applications, such as biosensors. It is shown that the inclusion in a nanocage and the potential difference between the cavity walls and the protein surface determines the energy of the system, thus altering the observed stabilization effect. Based on these results, the charge type and density of the cage must be controlled for optimum protein stabilization, which will result the improvement of a biosensor performance, especially regarding its signal stability and lifetime.

Reference: Chaniotakis, N., & Androulidaki, M. (2026). Nanocage-Mediated Enzyme Stabilization: The Effect of Size and Charge. Sensors and Actuators B: Chemical, 140690. Doi: https://doi.org/10.1016/j.snb.2026.140690

In a study published in Nature Communications (2026), a team of researchers from ICFO (Barcelona, Spain), TU Wien (Vienna, Austria), UCL (London, UK), MBI (Berlin, Germany), and IESL-FORTH (Heraklion, Greece) presented a solution to an important emerging open problem: understanding how bright squeezed vacuum (BSV) light propagates through nonlinear media, undergoing high-harmonic generation and how this propagation influences both the generated nonlinear signals and the quantum properties of the radiation. The work, led by Paraskevas Tzallas, establishes a fully quantized theoretical framework for investigating BSV-driven nonlinear optical processes, providing a foundation for future research in nonlinear optics, strong-field quantum optics, and ultrafast science across all states of matter.

Reference:

[1] J. Rivera-Dean, D. Kanti, P. Stammer, S. Carlström, N. Tsatrafyllis, M. Yu Ivanov, M. Lewenstein, and P. Tzallas, Nature Commun., (2026). (https://www.nature.com/articles/s41467-026-75173-8).

A new study by researchers at IESL-FORTH and the University of Crete, in collaboration with colleagues from the National Institute for Materials Science (NIMS), Japan, demonstrates the formation of dipolar interlayer excitons in heterobilayers composed of transition metal dichalcogenide alloys. By combining alloy engineering with van der Waals heterostructures, the team observed long-lived interlayer excitons exhibiting excitation-power-dependent energy shifts, revealing strong dipolar interactions between excitons. These findings establish alloyed two-dimensional semiconductors as a promising platform for tailoring excitonic properties and exploring next-generation excitonic and quantum optoelectronic devices.

Reference: Katsipoulaki, E., Chatzarakis, N. G., Rigoutsou, E., Katrisioti, D., Taniguchi, T., Watanabe, K., ... & Paradisanos, I. (2026). Dipolar interlayer excitons in transition metal dichalcogenide alloy heterobilayers. Journal of Physics: Materials. Doi: 10.1088/2515-7639/ae9192

Researchers from IESL-FORTH, Danae Katrisioti and Ioannis Paradisanos (affiliations: IESL-FORTH and MSE - UOC), together with collaborators from LAAS-CNRS have developed a versatile planarization strategy that allows atomically thin materials to be integrated with silicon nanoantennas while preserving strong optical near-field enhancement.

The approach is largely independent of antenna geometry and overcomes one of the key challenges in nano-optics: bringing two-dimensional materials within nanometers of optical hotspots without introducing significant strain or surface irregularities. The work paves the way for scalable hybrid nanophotonic platforms with applications in enhanced light–matter interactions, spectroscopy, and future optoelectronic devices.

Reference: Jonas Müller, Danae Katrisioti, Peter R. Wiecha, Nicolas Mallet, Anna E. Holz, Sylvain Pelloquin, Aurélie Lecestre, Jean-Marie Poumirol, Ioannis Paradisanos, Guilhem Larrieu; Geometry-Independent Nanometric Planarization of 3D Nanostructures for Strain-Controlled Integration of 2D Materials. ACS Appl. Mater. Interfaces 5 August 2026; 18 (30): 42011–42019. https://doi.org/10.1021/acsami.6c07634

Collaborative research by FORTH’s QMM Lab reveals that organic-molecule-intercalated iron superconductors — despite reaching a high T_c of 39 K —  struggle to carry high current.

Superconductors carry electricity with zero resistance and underpin technologies from MRI scanners to fusion reactors. Yet what determines their real-world usefulness isn't only how cold they must be — it's how much current they can sustain, known as the critical current density (J_c).

In a new study published in Superconductor Science and Technology, Myrsini Kaitatzi and Alexandros Lappas (IESL-FORTH & University of Crete) probe this trade-off in an iron selenide (FeSe) superconductor whose transition temperature (T_c) is raised from 8 K to nearly 39 K by intercalating lithium and pyridine molecules between its atomically thin 2D layers. This structural modification expands the interlayer spacing and enhances superconductivity — but the soft-chemistry synthesis route required to achieve it also yields a polycrystalline material with an inherently complex micro/nanostructure.

Using contact-free trapped-flux magnetization measurements, the team compared a single-phase powder with a densified pellet. Both showed J_c values (~10³ A cm^-2) roughly an order of magnitude below single-crystal FeSe, driven primarily by weak intergranular coupling that lets magnetic vortices penetrate too readily across grain boundaries. Residual impurity phases further degraded performance in the pellet, despite improved grain-to-grain contact upon pelletization.

The results sharpen a broader materials-science challenge: unlocking the high transition temperatures offered by molecular intercalation demands equal attention to disorder and microstructural control — grain connectivity, phase purity, and densification — if these quantum materials are to progress from laboratory curiosities toward viable high-field superconducting wires.

Citation: M. Kaitatzi & A. Lappas, Supercond. Sci. Technol. 39 065014 (2026).

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The Institute of Electronic Structure and Laser (IESL) of the Foundation for Research and Technology – Hellas (FORTH) announces the election of Dr. Emmanuel Stratakis as its new Director, marking the beginning of a new era of scientific excellence, innovation, and international collaboration for one of Europe's leading research institutes.

The election process was concluded following the meeting of the Special Evaluation Committee on 25 June 2026. Prior to the Committee's deliberations, IESL personnel—including researchers, collaborating faculty members, scientific, technical, administrative, and support staff—were invited to express their views on the candidates through FORTH's established digital consultation platform. This institutional consultation forms an important part of the selection process, providing the Committee with valuable insight into the candidates' leadership qualities, vision, and ability to guide the Institute's future development.

A globally recognized scientist in the fields of ultrafast lasers, laser–matter interaction, and nanophotonics, Dr. Stratakis has devoted more than two decades to pioneering research at IESL-FORTH, significantly contributing to the Institute's international reputation as one of Europe's premier research centres.

Dr. Stratakis received his Ph.D. in Physics from the University of Crete in 2001. Following his doctoral studies, he joined IESL-FORTH as a Visiting Researcher, focusing on ultrafast laser engineering of materials. He also served as a Visiting Researcher at the University of California, Berkeley, Department of Mechanical Engineering, during the fall semesters of 2006 and 2008. In 2007, he was elected Researcher at IESL-FORTH, where he established and continues to lead the internationally recognized Ultrafast Laser Micro- and Nano-processing Laboratory.

Reflecting his long-standing commitment to the Institute's leadership and strategic development, Dr. Stratakis served as Vice Director of IESL from April 2023 to April 2025. In May 2025, he was appointed Acting Director of IESL, a position he held until his election as Director, ensuring continuity in the Institute's scientific and administrative leadership.

His scientific achievements include more than 300 publications in peer-reviewed journals, over 17,000 citations, and an h-index of 71 (Google Scholar). Throughout his career, he has coordinated numerous national and European research projects, delivered more than 150 invited and keynote lectures, and served as organizer and chair of major international scientific conferences.

Dr. Stratakis has served on the editorial boards in several leading international journals, including Optoelectronic Advances, Optoelectronic Technology, Optics and Laser Technology, Materials Today Bio, and the International Journal of Molecular Sciences. Since 2015, he has served as Director of the FORTH Nanoscience Facility, a key node of the NFFA-Europe European Research Infrastructure, while also participating in its General Assembly. In addition, he serves as a National Expert in the European Union High-Level Group on Nanotechnologies, Advanced Materials, Biotechnology, Advanced Manufacturing and Processing, is an OPTICA Fellow, a European Innovation Council Ambassador, and Founder and Chief Executive Officer of Biomimetic. His contributions have been recognized with numerous international awards - distinctions, and he is consistently ranked among the top 2% of scientists worldwide.

Dr. Stratakis' election reflects both his outstanding scientific achievements and his long-standing commitment to IESL and FORTH. Under his leadership, the Institute is expected to further strengthen its position as a global centre of excellence, advancing frontier research, fostering innovation, expanding international partnerships, and translating scientific discoveries into societal and technological impact.

The entire IESL-FORTH community extends its warmest congratulations to Dr. Emmanuel Stratakis and wishes him every success in his new role as Director of IESL.