In progress – view active session
Conference 11883
Photoemission Spectroscopy for Materials Analysis
28 - 30 September 2021 | Carron 1
View Session 
Session 1:
Photoemission Studies of Electronic Structure
28 September 2021 • 2:00 PM - 3:30 PM BST | Carron 1
Session Chair:
Robert Palgrave, Univ. College London (United Kingdom)
11883-1
28 September 2021 • 2:00 PM - 2:30 PM BST | Carron 1
Show Abstract +
New wide and ultra wide band gap materials are necessary to develop more advanced generations of power electronic devices, ultimately improving their energy-efficiency and reliability. Ga2O3 is an interesting alternative to established materials such as SiC and GaN. In this work, polymorphs of Ga2O3 are investigated using X-ray diffraction, soft and hard X-ray photoelectron and absorption spectroscopy, and ab initio theoretical approaches to gain insights into their structure–electronic structure relationships. By combining state-of-the-art materials characterisation and electronic structure theory this work provides detailed insights into how changes in local coordination directly affect both core levels as well as valence and conduction electronic structure. The fundamental understanding of this relationship enables targeted tuning of materials properties which help to move towards integrating Ga2O3 in future power electronic device generations.
11883-2
28 September 2021 • 2:30 PM - 2:50 PM BST | Carron 1
Show Abstract +
One of the principal challenges in X-ray Photoelectron Spectroscopy is the assignment of detected spectral features to specific structural motifs within the sample. First principles modelling can assist the interpretation of experimental spectra by providing an independent means for determining core electron binding energies for various chemical environments. In this talk, the Delta-Self-Consistent-Field (Delta-SCF) method for calculating core electron binding energies will be introduced, and in turn, the application of the Delta-SCF method to free molecules, periodic solids, and adsorbates on surfaces will be discussed. Recent results, demonstrating the prediction of highly accurate absolute core electron binding energies in solids using a parameter-free first principles method (arxiv.org/abs/2104.06356) will be presented.
11883-3
28 September 2021 • 2:50 PM - 3:10 PM BST | Carron 1
Show Abstract +
Quantifying the crystallographic phases present at the surface of a material is an important challenge in heterogeneous catalysts. Valence band X-ray photoelectron spectroscopy was used to map the anatase to rutile ratio, with probing depth of around 5 nm, across the surface of mixed phase TiO2 films deposited by chemical vapour deposition on 25 x 25 mm2 quartz substrates. Theoretical photoemission spectra were calculated within the framework of Density Functional Theory and fitted to the experimental spectra in addition to empirical fitting of pure phase XPS spectra. Photocatalytic activity was correlated with the XPS determined phase fraction.
11883-4
28 September 2021 • 3:10 PM - 3:30 PM BST | Carron 1
Show Abstract +
The benefits of using GCIBs for depth profiling of inorganic materials is less clear, due to issues of preferential sputtering still remaining and artefacts being introduced. XPS depth profiles have been recorded for GaAs (100) wafers using GCIBs of varying beam energies and cluster sizes to investigate the effects of different GCIB conditions on the preferential sputtering of As and ion beam induced microtopography. GCIB bombardment of GaAs has also been modelled using the molecular dynamics (MD) code to provide an insight into the effects of using different GCIB conditions for XPS depth profiling of compound semiconductors, such as GaAs
Session 2:
Multitechnique Surface Analysis
28 September 2021 • 4:00 PM - 4:50 PM BST | Carron 1
Session Chair:
Rosa Arrigo, Univ. of Salford (United Kingdom)
11883-5
28 September 2021 • 4:00 PM - 4:30 PM BST | Carron 1
Show Abstract +
Lithium-ion batteries (LIBs) are key to the transition from fossil fuels towards increased use of renewable energy sources, but their cycle-life is limited by degradation processes. We report here detailed ex-situ studies of the interfacial degradation in Ni-rich LiNixMnyCozO2 (NMC) cathode materials cycled vs. graphite. We connect electrochemical signatures of cell degradation with interfacial characterisation with Hard X-ray Photoelectron Spectroscopy (HaXPES), to reveal chemical signatures of different degradation regimes. We then introduce several complementary approaches to performing operando x-ray photoelectron and absorption spectroscopy (XPS/XAS), demonstrating how these can resolve solid-electrolyte interphase (SEI) formation on Li-ion battery anodes.
11883-18
28 September 2021 • 4:30 PM - 4:50 PM BST | Carron 1
Show Abstract +
The rhenium dichalcogenides are unique members of the transition metal dichalcogenide(TMD) family as their properties are virtually independent of the number of layers unlike other TMDs. This is due to weak interlayer coupling which arises from the strong in-layer anisotropy.
Here, the core levels, valence band, work function and ionisation potentials of ReS2 and ReSe2 are investigated using x-ray photoemission spectroscopy (XPS). Furthermore, soft XPS and hard XPS were utilised to take advantage of the probing depth and change in photoionisation cross-sections. Allowing an investigation into the contributions to the valence band as well as investigating overlapping core level features.
11883-6
CANCELED: XPS with complementary multi-technique analysis of carbon materials
28 September 2021 • 4:30 PM - 4:50 PM BST | Carron 1
Show Abstract +
Understanding the surface chemistry of carbonaceous materials is of importance in a range of fields, especially with the somewhat exponential increase in the study of graphene and related materials. Such carbon materials can vary in elemental content, surface chemistry and nanostructure which will all influence the observed XPS spectrum.
Whilst there have been many methods to elucidate chemical states, including SP2-SP3 ratios using XPS, they have all been reported with varying success. Here in we present a coincident multi-technique analysis of carbon materials and discuss the merits of such coincident analysis
Wednesday Plenary Session
29 September 2021 • 9:00 AM - 10:00 AM BST | Lomond Auditorium
09:00: Welcome, Introduction, and Special Announcement
David Andrews, SPIE President, Univ. of East Anglia (United Kingdom)
09:20: Understanding the Role of Photonics in a Changing World
Carol Monaghan, Member of the Science and Technology Select Committee, Parliamentary Office of Science and Technology (board member), Industry and Parliament Trust (board member), Chair of the All-Party Parliamentary Group on Photonics and Quantum, Vice Chair All Party Parliamentary Group on Space (United Kingdom)
For decades, the photonics industry has been at the forefront of global innovation and research. Developments such as advanced LIDAR systems for autonomous vehicles, secure quantum computers and 5G communications, ensure that this sector remains as relevant as ever with the potential for major growth across multiple technologies. However increased threats to national security mean that the importance of this industry goes beyond basic economics. Set against a backdrop of a challenging funding landscape, can governments really afford not to invest in photonics and quantum?
Carol Monaghan graduated from the University of Strathclyde in 1993 with a BSc (Hons) in Laser Physics and Optoelectronics before training as a physics teacher. Her 20-year teaching career included 14 years as Head of Physics and Science at Hyndland Secondary. Carol was first elected as the MP for Glasgow North West in 2015 and re-elected in 2017 and 2019. She is the SNP’s Westminster Spokesperson for Education, Armed Forces and Veterans.
09:45: Question & Answer with Carol Monaghan
09:55: Welcome by Lord Provost of the City of Glasgow
David Andrews, SPIE President, Univ. of East Anglia (United Kingdom)
09:20: Understanding the Role of Photonics in a Changing World
Carol Monaghan, Member of the Science and Technology Select Committee, Parliamentary Office of Science and Technology (board member), Industry and Parliament Trust (board member), Chair of the All-Party Parliamentary Group on Photonics and Quantum, Vice Chair All Party Parliamentary Group on Space (United Kingdom)
For decades, the photonics industry has been at the forefront of global innovation and research. Developments such as advanced LIDAR systems for autonomous vehicles, secure quantum computers and 5G communications, ensure that this sector remains as relevant as ever with the potential for major growth across multiple technologies. However increased threats to national security mean that the importance of this industry goes beyond basic economics. Set against a backdrop of a challenging funding landscape, can governments really afford not to invest in photonics and quantum?
Carol Monaghan graduated from the University of Strathclyde in 1993 with a BSc (Hons) in Laser Physics and Optoelectronics before training as a physics teacher. Her 20-year teaching career included 14 years as Head of Physics and Science at Hyndland Secondary. Carol was first elected as the MP for Glasgow North West in 2015 and re-elected in 2017 and 2019. She is the SNP’s Westminster Spokesperson for Education, Armed Forces and Veterans.
09:45: Question & Answer with Carol Monaghan
09:55: Welcome by Lord Provost of the City of Glasgow
11880-500
Understanding the Role of Photonics in a Changing World
(Plenary Presentation)
29 September 2021 • 9:00 AM - 10:00 AM BST | Lomond Auditorium
Show Abstract +
For decades, the photonics industry has been at the forefront of global innovation and research. Developments such as advanced LIDAR systems for autonomous vehicles, secure quantum computers and 5G communications, ensure that this sector remains as relevant as ever with the potential for major growth across multiple technologies. However increased threats to national security mean that the importance of this industry goes beyond basic economics. Set against a backdrop of a challenging funding landscape, can governments really afford not to invest in photonics and quantum?
Session 3:
X-ray Photoelectron Spectroscopy of Functional Materials: Opportunities and Challenges I
29 September 2021 • 10:30 AM - 11:40 AM BST | Carron 1
Session Chair:
Rosa Arrigo, Univ. of Salford (United Kingdom)
11883-8
29 September 2021 • 10:30 AM - 11:00 AM BST | Carron 1
11883-9
29 September 2021 • 11:00 AM - 11:20 AM BST | Carron 1
Show Abstract +
For the last ten years XPS under near ambient pressure conditions (NAP-XPS) has gained significant attention in the XPS community. The technique allows for standard analysis of samples under pressures up to about 50 mbar. This opens XPS to liquids, solid-liquid interfaces, gas-solid-interfaces, gas-liquid-interfaces. New fields like operando studies on electrochemical systems, corrosion experiments, analysis of food samples, but also studies of biological samples have been added to the XPS portfolio. This presentation summarizes the special challenges in the interpretation of NAP-XPS data and uses several reference samples (mostly published in Surface Science Spectra) from different fields of application. Basic concepts for identification and quantification of spectral features are demonstrated. Finally an outlook is presented how close NAP-XPS is to be a routine metrology technique.
11883-10
29 September 2021 • 11:20 AM - 11:40 AM BST | Carron 1
Show Abstract +
X-rays are essential to a variety of advanced characterisation techniques. However, knowledge of its effect on small molecular crystals remains incredibly limited. In this study, a combined experimental and computational approach of synchrotron powder X-ray Diffraction and laboratory-based X-ray Photoelectron Spectroscopy (XPS) with Density Functional Theory, is implemented to understand changes to the structure, local chemical environments, and electronic structure of [M(COD)Cl]2 prototypical catalysts. Approaching this topic with these techniques allows for a compelling, multi-modal way to probe effects of X-ray irradiation, by way of a direct correlation of structural changes with changes of the chemical state of the metal.
Session 4:
2D Materials
29 September 2021 • 1:10 PM - 2:20 PM BST | Carron 1
Session Chair:
Phil King, Univ. of St. Andrews (United Kingdom)
11883-11
29 September 2021 • 1:10 PM - 1:40 PM BST | Carron 1
Show Abstract +
I will present some of our recent results applying angle-resolved photoemission spectroscopy with sub-micrometre spatial resolution (nanoARPES) to determine the local electronic structure in 2D heterostructures formed from stacks of two-dimensional materials (2DMs). 2DMs are frequently fabricated by mechanical exfoliation of layered crystals, resulting in atomically thin layers with uniform regions only a few micrometres across. The high spatial-resolution of nanoARPES enables direct measurement of the layer-dependent electronic properties of 2DMs, band alignments and interlayer interactions in 2D heterostructures, and twistronic effects. Beyond this, nanoARPES can be applied to 2D heterostructure devices, revealing changes in band structure with applied field.
11883-12
29 September 2021 • 1:40 PM - 2:00 PM BST | Carron 1
11883-13
29 September 2021 • 2:00 PM - 2:20 PM BST | Carron 1
Show Abstract +
Twisted bilayer graphene at the magic angle has become incredibly popular to study correlated phenomena due to the presence of a flat band at the Fermi level. Twisted multilayer graphene systems, like twisted double-bilayer graphene (TDBG) and twisted monolayer-bilayer graphene (TMBG), have been predicted to also host flat bands, but direct electronic structure measurements of this are lacking. Here we use angle-resolved photoemission spectroscopy to study the band structure of both TDBG and TMBG over a range of twist angles, revealing hybridisation gaps and the emergence of a flat band at the Fermi level at small twist angles.
Session 5:
X-ray Photoelectron Spectroscopy of Functional Materials: Opportunities and Challenges II
29 September 2021 • 4:00 PM - 5:30 PM BST | Carron 1
Session Chair:
Robert Palgrave, Univ. College London (United Kingdom)
11883-14
Utilising surface characterisation techniques to understand complex materials in chemical industry
(Invited Paper)
29 September 2021 • 4:00 PM - 4:30 PM BST | Carron 1
11883-15
29 September 2021 • 4:30 PM - 4:50 PM BST | Carron 1
Show Abstract +
For high-power semiconductor devices, a binary alloy of titanium and tungsten (TiW) is often used as a diffusion barrier to isolate the copper metallisation interconnects from the silicon substructure. However, high temperature events can promote interdiffusion phenomena between the adjacent layers, leading to the degradation and potential failure of the device.
To study these degradation mechanisms, Si/SiO2/TiW/(Cu) thin film stacks, annealed for varying durations, were characterised using a combination of soft and hard X-ray photoelectron spectroscopy (SXPS and HAXPES). The SXPS/HAXPES characterisation approach delivers a clear picture of the depth dependent behaviour of metallisation schemes under thermal stress, providing a detailed explanation of the degradation mechanisms.
11883-16
29 September 2021 • 4:50 PM - 5:10 PM BST | Carron 1
Show Abstract +
Near-Ambient-Pressure XPS (NAP-XPS) is a technique in which XPS can be performed in a non-vaccum environment. Lifting the restraint of vacuum compatibility not only allows to analyze samples which are not vacuum compatible (such as liquids, gasses or strongly outgassing samples), it can also drastically decrease sample introduction time and offers a new mechanism for charge compensation by gas ionization.
The NAP-XPS community has been steadily growing, fueled by a constant development of technology on the photon source and spectrometer side. The progress in experimental techniques is especially driven by fields such as catalysis, electrochemistry and hydrogen technology. These research fields benefit especially from the capability of NAP-XPS to analyze samples and devices under operation-like conditions, by measuring solid|liquid or solid|gas interfaces, by applying high temperatures or voltages, and by being able to control experimental boundaries in real time.
11883-17
29 September 2021 • 5:10 PM - 5:30 PM BST | Carron 1
Show Abstract +
Our everyday life is surrounded by surfaces. Engineered surfaces are critical for areas like aerospace, electronics, biomedical, space exploration, textile, packaging and many more. Atmospheric pressure plasma jets (APPJs) have found applications in the field of materials processing for much of the last century. One of the major advantages of non-thermal APPJs, is the abundance of chemically active species for reaction with different surfaces including organics. During plasma processing, a major part of chemical reactions takes place at the very surface of matter. To gain insight into these processes a tool is required that can provide information about the interactions between the atoms and molecules at the surface. Being highly surface sensitive , Photoemission spectroscopy is an ideal tool to understand the effects of plasma interactions with various surface. Photoemission spectroscopy has been critical in designing material specific plasma jets for a broad range of applications.
Thursday Plenary Session
30 September 2021 • 9:00 AM - 10:00 AM BST | Lomond Auditorium
09:00: Welcome and Introduction
David Andrews, SPIE President, Univ. of East Anglia (United Kingdom)
09:20: Strengthening Our Superpowers: Technology, Missions, and the UK Innovation Strategy
Simone Boekelaar, Innovate UK (United Kingdom)
What does HMG’s new Innovation Strategy tell us about how this government will intervene to promote emerging tech, and what it wants to achieve by doing so? What might this look like from the photonics’ sector’s perspective? A chance to hear about the evolution and objectives of the governments’ new innovation strategy, along with potential plans for implementation and industry engagement.
Simone Boekelaar is the Head of Horizon Scanning at Innovate UK, the UK government’s innovation agency. With a background in economics and engineering, Simone leads a team that scans for the emerging technologies and trends that will be most impactful on UK industry in 2030 and beyond. From health diagnostics to entertainment, from space travel to manufacturing glass bottles, Simone and her team scour the academic and industrial worlds to seek out the under-supported and overlooked technologies and trends likely to be critical to all our futures.
09:45: Question & Answer with Simone Boekelaar
David Andrews, SPIE President, Univ. of East Anglia (United Kingdom)
09:20: Strengthening Our Superpowers: Technology, Missions, and the UK Innovation Strategy
Simone Boekelaar, Innovate UK (United Kingdom)
What does HMG’s new Innovation Strategy tell us about how this government will intervene to promote emerging tech, and what it wants to achieve by doing so? What might this look like from the photonics’ sector’s perspective? A chance to hear about the evolution and objectives of the governments’ new innovation strategy, along with potential plans for implementation and industry engagement.
Simone Boekelaar is the Head of Horizon Scanning at Innovate UK, the UK government’s innovation agency. With a background in economics and engineering, Simone leads a team that scans for the emerging technologies and trends that will be most impactful on UK industry in 2030 and beyond. From health diagnostics to entertainment, from space travel to manufacturing glass bottles, Simone and her team scour the academic and industrial worlds to seek out the under-supported and overlooked technologies and trends likely to be critical to all our futures.
09:45: Question & Answer with Simone Boekelaar
11882-500
Strengthening our Superpowers: Technology, Missions, and the UK Innovation Strategy
(Plenary Presentation)
30 September 2021 • 9:00 AM - 10:00 AM BST | Lomond Auditorium
Show Abstract +
What does HMG’s new Innovation Strategy tell us about how this government will intervene to promote emerging tech, and what it wants to achieve by doing so? What might this look like from the photonics’ sector’s perspective? A chance to hear about the evolution and objectives of the governments’ new innovation strategy, along with potential plans for implementation and industry engagement.
Program Committee
Russell Edgell
Univ. of Oxford (United Kingdom)
Program Committee
David Morgan
HarwellXPS (United Kingdom)