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📰 News | New Publications
📰 News | New Publications
Ambipolar to anti-ambipolar light-induced transition in WSe2-based FETs
Ambipolar to anti-ambipolar light-induced transition in WSe2-based FETs
K. Intonti, A. Mazzotti, A. Pelella, F. Giubileo, N. Martucciello, S. O’Sullivan, V. Patil, P. K. Hurley, L. Ansari, F. Gity, A. Di Bartolomeo
Materials Horizons (2026)
This study reports a light-induced transition from ambipolar to anti-ambipolar transport in WSe2-based field-effect transistors. While the devices exhibit ambipolar behaviour with dominant n-type conduction in the dark, optical illumination triggers a pronounced anti-ambipolar response, characterized by a sharp current peak within a narrow gate voltage range. This behaviour enables three distinct current states suitable for multi-level logic applications. The photocurrent peak scales linearly with light intensity, yielding a responsivity of up to 0.13 A/W under red laser illumination. The observed behaviour is interpreted using energy band diagrams, linking the photocurrent peak to the n–p transition point.
🔗 Read the paper:
https://pubs.rsc.org/en/content/articlehtml/2026/mh/d5mh01871d
Collaborating institutions:
Tyndall National Institute (Ireland), University of Salerno & CNR (Italy)
📰 News | New Publications
📰 News | New Publications
Oxidation-driven structural, chemical and electrical transformation in ZrSe2
Oxidation-driven structural, chemical and electrical transformation in ZrSe2
K. Intonti, H. Neill, S. Jamalzadeh Kheirabadi, Z. Aslam, T. Moorsom, J. S. Prasanna, R. Addou, L. Persichetti, A. Sgarlata, L. Camilli, S. O’Sullivan, V. Patil, D. Singh, B. Sheehan, P. K. Hurley, L. Ansari, A. Di Bartolomeo, F. Gity
Materials Today Nano (2025)
In this work, we present a comprehensive investigation of the oxidation-driven degradation of the two-dimensional transition metal dichalcogenide ZrSe2. By combining AFM, SEM, STM, EDX, XPS, and Raman spectroscopy with density functional theory (DFT) simulations, we reveal the time-dependent evolution of surface morphology, chemical composition, and device performance under ambient conditions. Oxidation is shown to initiate at defect sites and edges, leading to native Zr oxide formation and selenium segregation into Se-rich protrusions and nanowires. Encapsulation with a thin ZrO2 layer is demonstrated as an effective strategy to mitigate degradation and improve device stability.
🔗 Read the paper:
https://doi.org/10.1016/j.mtadv.2025.100654
Collaborating institutions:
Tyndall National Institute (Ireland), University of Salerno and CNR (Italy), University of Leeds (UK), University of Rome “Tor Vergata” (Italy), University of Texas at Dallas (USA).
Science Communication: Science Week Outreach Activity
As part of Science Week, members of the 2D-MADE group carried out an outreach visit to Educate Together National School, Midleton, engaging with primary school students (ages 11-12).
The activity focused on making paper circuits, allowing students to explore the fundamentals of electricity and electronic circuits through hands-on learning. Using simple materials such as paper, copper tape, LEDs, and coin-cell batteries, the students combined creativity with problem-solving while gaining insight into how electronic devices work.
It was a pleasure to see the students’ enthusiasm and curiosity, and to contribute to inspiring the next generation of scientists and engineers.
Acknowledgements
This outreach activity was supported by Research Ireland, IPIC, AMBER, and Tyndall National Institute, with particular thanks to Tyndall’s EPE Officer, Claire Law, for her great support.
Sharieh Jamalzadeh Kheirabadi, a Marie Skłodowska-Curie Actions (MSCA) postdoctoral researcher in our group, delivered an oral presentation at the European Materials Research Society (EMRS) 2025 conference in Strasbourg, France, held from 26–30 May 2025. Her talk, titled "The Role of Vacancy Defects and Au Ion Mobility in MoS2 2D Memristors", focused on the influence of sulfur vacancies and gold ion dynamics in the operation of MoS2-based memristor devices. The study included detailed electronic structure calculations based on fully relativistic density functional theory (DFT).
Sharieh Jamalzadeh Kheirabadi, a Marie Skłodowska-Curie Actions (MSCA) postdoctoral researcher in our group, participated in the Journées de la Matière Condensée (JMC) 2024 held in Marseille, France, from 28–31 October 2024. She presented a poster entitled "Twisted PtTe2: Moiré Engineering", highlighting the significant influence of twist angle on the electronic properties of PtTe2 and discussing the structural stability of twisted configurations.
Sharieh Jamalzadeh Kheirabadi, an MSCA (Marie Skłodowska-Curie Actions) postdoctoral researcher in our group, attended the European Graphene Forum (EGF) 2024 in Barcelona, Spain (23–25 October 2024). She gave an oral presentation entitled "Moiré Engineering in Twisted WTe2 Structures". Her research demonstrates that varying the twist angle between layers of WTe2 significantly influences the electronic and magnetic properties of the system. The work highlights the unique potential of twisted van der Waals structures, offering new opportunities to explore emergent physical phenomena in 2D materials through symmetry control.
Hazel Neill, one of the group's PhD students, recently attended the Quantum Matter 2025 international conference in Grenoble, France, from 19-23rd May 2025, where she presented a poster entitled "Air Sensitivity Analysis of 2D Superconductor Materials for Advanced Josephson Junction". The study looked into two well-known superconducting materials and their stability in air over a period of 4 months.
Hazel Neill, one of the group's PhD students, recently attended the Quantum Matter 2025 international conference in Grenoble, France, from 19-23rd May 2025, where she presented a poster entitled "Air Sensitivity Analysis of 2D Superconductor Materials for Advanced Josephson Junction". The study looked into two well-known superconducting materials and their stability in air over a period of 4 months.
Stephen O'Sullivan, one of the group's PhD students, presented at the Pint of Science Ireland event in Cork, on 20th of May. Pint of Science is a global science outreach event that hosts talks on research in a pub setting with the aim of improving the public's understanding of ongoing research. His talk covered the evolution of microelectronics and an introduction to 2D materials.
Stephen O'Sullivan, one of the group's PhD students, presented at the Pint of Science Ireland event in Cork, on 20th of May. Pint of Science is a global science outreach event that hosts talks on research in a pub setting with the aim of improving the public's understanding of ongoing research. His talk covered the evolution of microelectronics and an introduction to 2D materials.
In January 2025, one of the groups PhD students, Stephen, attended the UCC postgrad expo on behalf of Tyndall National Institute (TNI) to discuss the wide range of postgraduate research opportunities available at TNI with UCC students.
We are excited to announce that our group will be attending the prestigious IEDM Conference this year on Dec 7-11 in San Francisco. This event provides a fantastic opportunity to discuss our work on 2D materials, share insights, and explore potential collaborations.
If you are attending the conference, we would be delighted to connect and chat about advancing research in nanoelectronics and beyond. Let’s work together to push the boundaries of innovation!
You are welcome to visit our talk on Wednesday, December 11th, Session 32-3.
https://iedm24.mapyourshow.com/8_0/sessions/session-details.cfm?ScheduleID=247
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