A5066275038- 2D Materials and Applications
- Semiconductor materials and devices
- Photonic and Optical Devices
- Semiconductor materials and interfaces
- MXene and MAX Phase Materials
- Advancements in Semiconductor Devices and Circuit Design
- Semiconductor Quantum Structures and Devices
- Semiconductor Lasers and Optical Devices
- Graphene research and applications
- Nanowire Synthesis and Applications
- Thin-Film Transistor Technologies
- Advanced Memory and Neural Computing
- Chalcogenide Semiconductor Thin Films
- Silicon Carbide Semiconductor Technologies
- ZnO doping and properties
- Ferroelectric and Negative Capacitance Devices
- Silicon and Solar Cell Technologies
- Integrated Circuits and Semiconductor Failure Analysis
- Surface and Thin Film Phenomena
- Gas Sensing Nanomaterials and Sensors
- Advanced Optical Sensing Technologies
- Perovskite Materials and Applications
- Transition Metal Oxide Nanomaterials
- Optical Network Technologies
- Molecular Junctions and Nanostructures
University College Cork
2016-2025
Trinity College Dublin
2020-2025
Advanced Materials and BioEngineering Research
2020-2025
Tyndall Centre
2018-2023
National University of Ireland
2017-2021
University of Salerno
2020
Advanced Materials and Devices (United States)
2020
Tyndall National Institute
2009-2017
Lake Shore Cryotronics (United States)
2017
International Energy Research Centre
2011-2012
A surface sensitivity study was performed on different transition-metal dichalcogenides (TMDs) under ambient conditions in order to understand which material is the most suitable for future device applications. Initially, Atomic Force Microscopy and Scanning Electron studies were carried out over a period of 27 days mechanically exfoliated flakes 5 TMDs, namely, MoS2, MoSe2, MoTe2, HfS2, HfSe2. The reactive MoTe2 HfSe2, particular, showed protrusions after exposure, reaching height width...
Platinum diselenide (PtSe2) is a group-10 transition metal dichalcogenide (TMD) that has unique electronic properties, in particular semimetal-to-semiconductor when going from bulk to monolayer form. We report on vertical hybrid Schottky barrier diodes (SBDs) of two-dimensional (2D) PtSe2 thin films crystalline n-type silicon. The have been fabricated by transferring large-scale layered films, synthesized thermally assisted conversion predeposited Pt at back-end-of-the-line CMOS compatible...
Abstract In this work, we present a comprehensive theoretical and experimental study of quantum confinement in layered platinum diselenide (PtSe 2 ) films as function film thickness. Our electrical measurements, combination with density functional theory calculations, show distinct layer-dependent semimetal-to-semiconductor evolution PtSe films, highlight the importance including van der Waals interactions, Green’s calibration, screened Coulomb interactions determination thickness-dependent...
The advent of two-dimensional materials has opened a plethora opportunities in accessing ultrascaled device dimensions for future logic and memory applications. In this work, we demonstrate that single layer large-area chemical vapor deposition-grown molybdenum disulfide (MoS2) sandwiched between two metal electrodes can be tuned to show multilevel nonvolatile resistive states with resistance values separated by 5 orders magnitude. switching process is unipolar thermochemically driven...
Abstract Mechanically exfoliated multilayer WS 2 flakes are used as the channel of field effect transistors for low-power photodetection in visible and near-infrared (NIR) spectral range. The electrical characterization a function temperature reveals devices with n-type conduction slightly different Schottky barriers at drain source contacts. phototransistors can be operated self-powered mode, yielding both current voltage when exposed to light. photoresponse NIR ranges shows high...
Abstract The properties and performance of two-dimensional (2D) materials can be greatly affected by point defects. PtTe 2 , a 2D material that belongs to the group 10 transition metal dichalcogenides, is type-II Dirac semimetal, which has gained lot attention recently due its potential for applications in catalysis, photonics, spintronics. Here, we provide an experimental theoretical investigation defects on near surface . Using scanning tunneling microscopy spectroscopy (STS) measurements,...
Two-dimensional transition metal dichalcogenides, such as MoS
Block copolymer (BCP) patterning is a well-established self-assembly technique for developing surfaces with regular and controllable nanosized features. This method relies on the microphase separation of BCP film subsequent infiltration inorganic species. The serves as template, leaving behind replicas when removed. offers promising, cost-effective alternative to standard nanopatterning techniques, featuring fewer processing steps reduced energy use. However, can be complex challenging...
In this paper, we examine the effects of subband quantization on efficacy an L-shaped gate vertical dopingless tunneling field-effect transistor. The proposed architecture leverages intrinsic interface that is fully aligned with metal, resulting in enhanced electrostatic control. We utilized a two-step numerical simulation approach grounded Schrödinger-Poisson equations to evaluate performance our device and accurately calculate ON-state current. Additionally, assessed influence defects at...
Abstract Graphene nanoribbons (GNRs) have emerged as promising candidates for nanoelectronic devices due to their unique electronic and transport properties. In this study, we investigate the impact of passivation on cove-edge graphene nanoribbon (CGNR) using both cadmium (Cd) hydrogen (H) atoms. Through a comprehensive density functional theory (DFT) analysis coupled with non-equilibrium Green’s function (NEGF) simulations, explore properties device behavior these passivated CGNRs. Our...
Tailoring the electrical properties of transition metal dichalcogenides by doping is one biggest challenges for application 2D materials in future electronic devices. Here, we report on a straightforward approach to n-type molybdenum disulfide (MoS2) films with rhenium (Re). High-Resolution Scanning Transmission Electron Microscopy and Energy-Dispersive X-ray spectroscopy are used identify Re interstitial lattice sites MoS2 structure. Hall-effect measurements confirm electron donating...
In this paper, state-of-the-art laser thermal annealing is used to fabricate Ge diodes. We compared the effect of (LTA) and rapid (RTA) on dopant activation electrical properties phosphorus Arsenic-doped n+/p junctions. Using LTA, high carrier concentration above 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">20</sup> cm xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup> was achieved in n-type doped regions, which enables low access...
Molybdenum ditelluride (MoTe2) is a transition metal dichalcogenide (TMD) which has two phases stable under ambient conditions, semiconducting (2H) and semimetallic (1T′) phase. Despite host of interesting properties potential applications, MoTe2 one the less-studied TMDs, perhaps due its relatively low abundance in nature or challenges associated with synthesis, such as toxicity most precursors. In this report, we describe fabrication thin films phase-pure 1T′ using predeposited molybdenum...
PtS e 2 ultrathin films are used as the channel of back-gated field-effect transistors that investigated at different temperatures and under super-continuous white laser irradiation. The temperature-dependent behavior confirms semiconducting nature multilayer PtSe2, with p-type conduction, a hole mobility up to 40 cm2 V−1 s−1, significant gate modulation. Electrical conduction measured along directions shows isotropic transport. A reduction PtSe2 conductance is observed exposure light. Such...
Abstract 2D materials display very promising intrinsic material properties, with multiple applications in electronics, photonics, and sensing. In particular layered platinum diselenide has shown high potential due to its layer‐dependent tunable bandgap, low‐temperature growth, environmental stability. Here, the conformal area selective (AS) growth of PtSe 2 is presented defining a new paradigm for integration. The thermally‐assisted conversion which deposited by AS atomic layer deposition...
The effect of rare-earth erbium (Er) doping on the electronic structure platinum diselenide (PtSe2) as a 2D transition metal dichalcogenide was studied using density functional theory (DFT). Our DFT calculations showed that Er dopant in PtSe2 led to formation additional states valence and conduction bands, new localized within band gap PtSe2. orbital-resolved revealed 4f orbitals atom strongly impact monolayer induce spin-polarized states. Simultaneously, addition significant increase...
The current transport across a p-Ge/n-Si diode structure obtained by direct wafer bonding and layer exfoliation is analysed. A low temperature anneal at 400 °C for 30 min was used to improve the forward characteristics of with on/off ratio −1 V being &gt;8000. Post anneal, mechanism has strong tunnelling component. This fabrication technique using thermal budget (T ≤ °C) an attractive option heterogeneous integration.
We report on the photoresponse of an asymmetrically doped p(-)-Ge/n(+)-Si heterojunction photodiode fabricated by wafer bonding. Responsivities in excess 1 A/W at 1.55 μm are measured with a 5.4 thick Ge layer under surface-normal illumination. Capacitance-voltage measurements show that interfacial band structure is dependent both temperature and light level, moving from depletion holes -50 °C to accumulation 20 °C. Interface traps filled photo-generated thermally-generated carriers shown...
Bismuth has been identified as a material of interest for electronic applications due to its extremely high electron mobility and quantum confinement effects observed at nanoscale dimensions. However, it is also the case that Bi nanostructures are readily oxidised in ambient air, necessitating additional capping steps prevent surface re-oxidation, thus limiting processing potential this material. This article describes an oxide removal stabilization method performed on molecular beam epitaxy...
Hybrid plasmonic lasers provide deep subwavelength optical confinement, strongly enhanced light-matter interaction and together with nanoscale footprint promise new applications in communication, bio-sensing photolithography. The hybrid reported so far often use bottom up grown nanowires, nanorods nanosquares, making it difficult to integrate these devices into industry-relevant high density circuits. Here, we report the first experimental demonstration of AlGaInP based, red-emitting at room...
Two-dimensional MoS2 is a promising material for applications, including electronics and electrocatalysis. However, scalable methods capable of depositing at low temperatures are scarce. Herein, we present toolbox advanced plasma-enhanced atomic layer deposition (ALD) processes, producing wafer-scale polycrystalline films accurately controlled thickness. Our ALD processes based on two individually plasma exposures, one optimized the other modification. In this way, film properties can be...
Direct growth of transition metal dichalcogenides over large areas within the back-end-of-line (BEOL) thermal budget limit silicon integrated circuits is a significant challenge for 3D heterogeneous integration.In this work, we report on MoS2 films (~1-10 nm) SiO2, amorphous-Al2O3, c-plane sapphire, and glass substrates achieved at low temperatures (350-550 °C) by chemical vapor deposition in manufacturing-compatible 300 mm atomic layer reactor.We investigate as potential material solution...