Investigation of the Radiation Damage Mechanisms in Two-Dimensional Materials under Gamma and Ion Irradiation

Lead Research Organisation: University of Manchester
Department Name: Chemistry

Abstract

The project will be focused on the synthesis and post-irradiation characterisation of a number of 2D transition metal dichalcogenides (TMDCs), hexagonal boron nitride (h-BN) and graphene in order to elucidate the radiation damage mechanisms in these materials. The importance of the proposed study is justified by the outstanding electronic and optoelectronic properties of 2D materials, which make this class of compounds a good candidate for applications in various electronic devices, including radiation dosimeters and detectors. While exceptionally high resistance of graphene against ionising radiation is well recognised, the radiation hardness of the structurally related to graphene 2D inorganic compounds (such as h-BN, MoS2, and WS2) haven't been studied systematically. It is expected that the radiation damage in inorganic 2D materials will be quite different from graphene due to more complex layered structure and multi-element chemical composition of these compounds. To the best of our knowledge, there are just a few irradiation studies of 2D materials that can be found in literature. Majority of these investigations relies on the transmission electron microscopy as a tool for in situ radiation damage by energetic electrons and simultaneous defect observation. This experimental approach yields valuable information about the mechanisms of defect formation under electron irradiation. However, it does not represent harsh radiation conditions found in high-energy accelerators and colliders, radiotherapy facilities or nuclear reactors. In these environments, electronic devices containing inorganic 2D materials will be exposed to the high energy and high dose mixed radiation fields. We suggest that gamma and ion irradiation can be used to mimic those conditions. The Co60 irradiator and the 5MV tandem ion accelerator at the Dalton Cumbrian Facility (DCF) will be deployed to produce lattice damaged specimen by gamma rays and by heavy ion bombardment, respectively. Radiolytic changes in the studied 2D materials will be examined using Raman Spectroscopy, Fourier Transform Infrared Spectroscopy, Atomic Force Microscopy, Scanning Electron Microscopy and Transmission Electron Microscopy. Proposed extensive characterisation of irradiated two-dimensional materials will allow to quantify the extent of lattice damage and to gain a better understanding of the mechanisms of radiation-induced degradation. The proposed studies will make an important contribution to the fundamental understanding of radiation hardness (or instability) of the inorganic 2D materials and graphene.

Publications

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Isherwood L (2018) Alpha particle irradiation of bulk and exfoliated MoS2 and WS2 membranes in Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms

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Isherwood LH (2021) Gamma Radiation-Induced Oxidation, Doping, and Etching of Two-Dimensional MoS2 Crystals. in The journal of physical chemistry. C, Nanomaterials and interfaces

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Shin Y (2019) Charge-tunable graphene dispersions in water made with amphoteric pyrene derivatives in Molecular Systems Design & Engineering

Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/N509565/1 01/10/2016 30/09/2021
1725265 Studentship EP/N509565/1 18/09/2016 31/03/2020 Liam Harry Isherwood
 
Description - The interaction of charged particles with crystals can modulate their electronic properties.
- In irradiated layered three-dimensional materials, interactions between atoms in adjacent layers determine how the crystal vibrates. Whereas, when thinned down to a single two-dimensional layer, the confinement of vibrations between defects (introduced by radiaiton) determines how the crystal vibrates
- The liquid used to make two-dimensional materials can produce contamination when the crystal is irradiated
- When two-dimensional crystals just a few layers thick are irradiated with high energy particles of light, the uppermost layer is removed; starting from the edge first.
- When a single layer of material is irradiated with high energy particles of light, the defects produced alter how the material itself emits light.
- Overall, the funded work has yielded fundamental insights into (1) how radiation interacts with nanomaterials (vs bulk counterparts), (2) how defects can be used to tailor the properties of materials for real-world applications and (3) how suitable are two-dimensional materials for applications in radiation environments
Exploitation Route The funded work has shown that the chemical composition and optoelectronic properties of two-dimensional MoS2 are significantly altered by gamma irradiation. If this material is to be included in applications within the vicinity of nuclear reactors then these fundamental insights could be developed into a clear understanding of device performance through fabrication, irradiation and characterisation work packages.
Sectors Electronics,Energy