Turning interlayer coupling into a device-design tool

We are excited to announce a new publication arising from a close collaboration between Tyndall National Institute and Synopsys QuantumATK.

The study shows that a perpendicular electric field can reshape the interlayer energy landscape of bilayer PtTe2, driving it from its equilibrium metallic configuration toward an expanded semiconducting state. This field-controlled structural change weakens interlayer hybridisation and opens a bandgap of up to approximately 0.44 eV.

Using DFT, electric-field-dependent nudged elastic band calculations and quantum transport simulations, the work demonstrates how this mechanism can combine a conductive metallic ON state with a strongly suppressed semiconducting OFF state. The resulting model achieves a large ON/OFF current ratio and subthreshold swing of approximately 75 mV/dec, while remaining within the thermionic switching regime.

Published in: Materials Today Electronics
Read the paper:
https://www.sciencedirect.com/science/article/pii/S2772949426000343

Collaboration:
Tyndall National Institute, University College Cork & Synopsys QuantumATK, Synopsys Denmark ApS

Acknowledgements:

• Marie Skłodowska-Curie Actions, 101109772

• Research Ireland Frontiers for the Future PI Award, 24/FFP-A/13329

• Research Ireland AMBER Research Centre, SFI-12/RC/2278_P2

• HPC support from ICHEC

A dopant-free route toward low-power 2D logic devices

We are pleased to announce a new open-access publication in Advanced Electronic Materials exploring how crystallographic orientation can be used to improve the performance of ultra-scaled PtTe2 transistors.

Using first-principles quantum transport simulations, the study investigates monomaterial Schottky-junction FETs in which semimetallic bilayer PtTe2 acts as the source and drain, while semiconducting monolayer PtTe2 forms the channel. This thickness-controlled architecture enables carrier injection without external doping or heterojunction interfaces.

The work shows that transport along the Γ–M direction provides a clear advantage over Γ–K transport, combining stronger ON-state current, lower leakage, improved electrostatic control and subthreshold swings as low as 75 mV/dec in the 7 nm device configuration. These results highlight orientation engineering as a powerful design strategy for future low-power, beyond-CMOS nanoelectronics.

Published in: Advanced Electronic Materials
Read the paper:
https://advanced.onlinelibrary.wiley.com/doi/10.1002/aelm.70464

Acknowledgements:

• Research Ireland AMBER Research Centre, SFI-12/RC/2278_P2

• Research Ireland Frontiers for the Future PI Award, 24/FFP-A/13329

• HPC support from ICHEC

How defects, interfaces and air exposure shape 2D transistor performance

We are pleased to announce a new publication in Journal of Materials Chemistry C on the electrical behaviour of ultrathin MoTe2 field-effect transistors.

Through a combined experimental and density-functional-theory study, the work reveals how intrinsic vacancies, metal/semiconductor interfaces, dielectric traps, thermal treatment and surface adsorbates collectively influence charge transport in MoTe2 devices. Temperature-dependent measurements identify low and nearly symmetric Schottky barriers at the Ni/MoTe2 contacts, while pressure-dependent measurements show how molecular adsorption can reduce mobility and alter p-type conduction.

The study also shows how vacancy-related defect states and oxygen passivation can modify carrier transport, offering practical guidance for defect and interface engineering in future two-dimensional semiconductor devices.

Published in: Journal of Materials Chemistry C
Read the paper:
https://pubs.rsc.org/en/content/articlelanding/2026/tc/d6tc00385k

Collaboration:
Tyndall National Institute, University College Cork, Ireland & University of Salerno, Italy

Acknowledgements:

• Research Ireland AMBER Research Centre, SFI-12/RC/2278_P2

• Research Ireland Frontiers for the Future PI Award, 24/FFP-A/13329

• EU Marie Skłodowska-Curie Actions, 101153933

• HPC support from ICHEC

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).

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).