|
|
James C
Blakesley
,
Ruy Sebastian
Bonilla
,
Marina
Freitag
,
Alex
Ganose
,
Nicola
Gasparini
,
Pascal
Kaienburg
,
George
Koutsourakis
,
Jonathan D.
Major
,
Jenny
Nelson
,
Nakita K.
Noel
,
Bart
Roose
,
Jae Sung
Yun
,
Simon
Aliwell
,
Pietro
Altermatt
,
Tayebeh
Ameri
,
Virgil
Andrei
,
Ardalan
Armin
,
Diego
Bagnis
,
Jenny
Baker
,
Hamish
Beath
,
Mathieu
Bellanger
,
Philippe
Berrouard
,
Jochen
Blumberger
,
Stuart
Boden
,
Hugo
Bronstein
,
Matthew J.
Carnie
,
Chris
Case
,
Fernando A.
Castro
,
Yi-Ming
Chang
,
Elmer
Chao
,
Tracey M.
Clarke
,
Graeme
Cooke
,
Pablo
Docampo
,
Ken
Durose
,
James
Durrant
,
Marina
Filip
,
Richard H.
Friend
,
Jarvist M.
Frost
,
Elizabeth
Gibson
,
Alexander J.
Gillett
,
Pooja
Goddard
,
Severin
Habisreutinger
,
Martin
Heeney
,
Arthur D.
Hendsbee
,
Louise C.
Hirst
,
Saiful
Islam
,
Imalka
Jayawardena
,
Michael
Johnston
,
Matthias
Kauer
,
Jeff
Kettle
,
Ji-Seon
Kim
,
Dan
Lamb
,
David G.
Lidzey
,
Jihoo
Lim
,
Roderick
Mackenzie
,
Nigel
Mason
,
Iain
Mcculloch
,
Keith
Mckenna
,
Sebastian
Meier
,
Paul
Meredith
,
Graham
Morse
,
John
Murphy
,
Chris
Nicklin
,
Paloma
Ortega-Arriaga
,
Thomas
Osterberg
,
Jay
Patel
,
Anthony
Peaker
,
Moritz
Riede
,
Martyn
Rush
,
James
Ryan
,
David O.
Scanlon
,
Peter
Skabara
,
Franky
So
,
Henry J.
Snaith
,
Ludmilla
Steier
,
Jarla
Thiesbrummel
,
Alessandro
Troisi
,
Craig
Underwood
,
Karsten
Walzer
,
Trystan M.
Watson
,
Michael
Walls
,
Aron
Walsh
,
Lucy D.
Whalley
,
Benedict
Winchester
,
Sam
Stranks
,
Robert
Hoye
Open Access
Abstract: Photovoltaics (PVs) are a critical technology for curbing growing levels of anthropogenic greenhouse gas emissions, and meeting increases in future demand for low-carbon electricity. In order to fulfil ambitions for net-zero carbon dioxide equivalent (CO2eq) emissions worldwide, the global cumulative capacity of solar PVs must increase by an order of magnitude from 0.9 TWp in 2021 to 8.5 TWp by 2050 according to the International Renewable Energy Agency, which is considered to be a highly conservative estimate. In 2020, the Henry Royce Institute brought together the UK PV community to discuss the critical technological and infrastructure challenges that need to be overcome to address the vast challenges in accelerating PV deployment. Herein, we examine the key developments in the global community, especially the progress made in the field since this earlier roadmap, bringing together experts primarily from the UK across the breadth of the photovoltaics community. The focus is both on the challenges in improving the efficiency, stability and levelized cost of electricity of current technologies for utility-scale PVs, as well as the fundamental questions in novel technologies that can have a significant impact on emerging markets, such as indoor PVs, space PVs, and agrivoltaics. We discuss challenges in advanced metrology and computational tools, as well as the growing synergies between PVs and solar fuels, and offer a perspective on the environmental sustainability of the PV industry. Through this roadmap, we emphasize promising pathways forward in both the short- and long-term, and for communities working on technologies across a range of maturity levels to learn from each other.
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Aug 2024
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B18-Core EXAFS
I21-Resonant Inelastic X-ray Scattering (RIXS)
|
Matthew
Ogley
,
Ashok S.
Menon
,
Beth J.
Johnston
,
Gaurav
Pandey
,
Innes
Mcclelland
,
Xiaoqun
Shi
,
Stefano
Agrestini
,
Veronica
Celorrio
,
Gabriel E.
Perez
,
Samuel G.
Booth
,
Jordi
Cabana
,
Serena A.
Cussen
,
Louis F. J.
Piper
Diamond Proposal Number(s):
[33292, 33173]
Open Access
Abstract: In layered lithium transition metal oxide cathodes, high-voltage operation is accompanied by the formation of oxygen dimers, which are widely used as an indicator of oxygen-redox activity. However, understanding the role that oxygen dimerization plays in facilitating charge compensation is still needed. Li2NiO3 (a 3d8L2-containing compound, where L is a ligand hole) is studied as a model system, where oxygen dimerization is shown to occur without cathode oxidation. Electrochemical cycling results in a net reduction of the cathode, accompanied by structural transformations, despite spectroscopic features of oxygen dimers arising at the top-of-charge. Here, oxygen dimerization is shown to coexist alongside a structurally transformed and electronically reduced cathode structure, thus highlighting that O dimerization is independent of bulk redox processes. This makes it clear that a thermodynamically derived transformation toward a reduced phase remains the only variable capable of generating O–O dimers in Li2NiO3.
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Aug 2024
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E02-JEM ARM 300CF
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Jihoo
Lim
,
Jaehui
Kim
,
Josh
Davies-Jones
,
Mohsen
Danaie
,
Eunyoung
Choi
,
Hongjae
Shim
,
Liang
Chen
,
Jincheol
Kim
,
Judy S.
Kim
,
Philip R.
Davies
,
Jan
Seidel
,
Martin
Green
,
Samuel D.
Stranks
,
Sang Il
Seok
,
Jae
Yun
Diamond Proposal Number(s):
[34931]
Abstract: Efforts to enhance the efficiency and stability of formamidinium lead triiodide (FAPbI3) perovskite solar cells (PSCs) have primarily focused on employing methylammonium chloride (MACl) as an effective additive. MACl significantly improves the crystallinity and lowers the δ-to-α phase transition temperature of FAPbI3, thereby contributing to the remarkable efficiency of these solar cells. However, upon evaporation with deprotonation of MACl during annealing, the highly reactive methylamine leads to the formation of N-methylformamidinium (MFA+) cations. Despite their potential for significant influence on the properties of FAPbI3 perovskites, the chemical and optoelectronic characteristics of MFA+ in FAPbI3 remain poorly understood. This study investigates the unexplored role of MFA+ in FAPbI3 perovskite with MACl incorporation through advanced nanoscale characterization techniques, including photo-induced force microscopy (PiFM), four-dimensional scanning transmission electron microscopy, and wavelength-dependent Kelvin probe force microscopy (KPFM). We reveal that MACl induces compositional heterogeneities, particularly formamidinium (FA+) and MFA+ cation inhomogeneities. Surprisingly, MACl selectively promotes the formation of MFAPbI3 at grain boundaries (GBs) and as clusters near GBs. Additionally, we confirm that MFAPbI3 is a wide bandgap, and charge carriers are effectively separated at GBs and clusters enriched with MFAPbI3. This is particularly interesting because MFAPbI3, despite its crystal structural similarity to yellow phase δ-FAPbI3, displays a high surface photovoltage, and does not deteriorate the solar cell performance. This study not only provides insights into the byproduct formation of MFA+ induced by local cation heterogeneity after employing MACl, but also guides a crucial perspective for optimizing formamidinium-based PSC design and performance.
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Aug 2024
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B18-Core EXAFS
I21-Resonant Inelastic X-ray Scattering (RIXS)
|
John-Joseph
Marie
,
Max
Jenkins
,
Jun
Chen
,
Gregory
Rees
,
Veronica
Celorrio
,
Jaewon
Choi
,
Stefano
Agrestini
,
Mirian
Garcia-Fernandez
,
Ke-Jin
Zhou
,
Robert A.
House
,
Peter G.
Bruce
Diamond Proposal Number(s):
[25785]
Open Access
Abstract: Achieving reversible O-redox through the formation of electron–holes on O could hold the key to a new generation of high energy density Na-ion cathodes. However, to date, it has only been demonstrated in a small handful of cathode materials and none of these materials exploit the dual benefit of high voltage transition metal redox and O-redox, instead relying on Mn3+/4+ capacity close to 2 V vs Na+/Na. Here, a new Na-ion cathode exhibiting electron–holes on O is demonstrated, P2-type Na0.67Li0.1Ni0.3Mn0.6O2, which also utilizes the high voltage Ni3+/4+ redox couple to deliver the highest reported energy density among this class of compound. By employing a low Li content and avoiding honeycomb ordering within the transition metal layer, it is possible to stabilize the hole states, and the high voltage plateau is preserved in Na0.67Li0.1Ni0.3Mn0.6O2 over cycling.
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Jul 2024
|
|
B07-C-Versatile Soft X-ray beamline: Ambient Pressure XPS and NEXAFS
|
Diamond Proposal Number(s):
[32763, 33640]
Open Access
Abstract: Suitable reaction cells are critical for operando near ambient pressure (NAP) soft X-ray photoelectron spectroscopy (XPS) and Near-edge X-ray absorption fine structure (NEXAFS) studies. They enable tracking the chemical state and structural properties of catalytically active materials under realistic reaction conditions, and thus allow a better understanding of charge transfer at the liquid-solid interface, activation of reactant molecules, and surface intermediate species. In order to facilitate such studies, we have developed a top-side illuminated operando spectro-electrochemical flow cell for synchrotron-based NAP-XPS and NEXAFS studies. Our modular design uses a non-metal (PEEK) body, and replaceable membranes which can be either of X-ray transparent silicon nitride (SiNx) or of water permeable polymer membrane materials (e.g., NafionTM). The design allows rapid sample exchange and simultaneous measurements of total electron yield (TEY), Auger electron yield (AEY) and fluorescence-yield (TFY). The developed system is highly modular and can be used in the laboratory or directly at the beamline for operando XPS/ X-ray absorption spectroscopy (XAS) investigations of surfaces and interfaces. We present examples to demonstrate the capabilities of the cell. These include an operando NEXAFS study of the Cu-redox chemistry using a SiNx membrane/Ti-Au/ Cu working electrode assembly (WEA) and a NAP-XPS and -NEXAFS study of water adsorption on a NafionTM polymer membrane based working electrode assembly (NafionTM/C/IrOx catalyst).
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Jun 2024
|
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I09-Surface and Interface Structural Analysis
|
Christopher
Don
,
Thomas P.
Shalvey
,
Daniya A.
Sindi
,
Bradley
Lewis
,
Jack E. N.
Swallow
,
Leon
Bowen
,
Daniel F.
Fernandes
,
Tomas
Kubart
,
Deepnarayan
Biswas
,
Pardeep K.
Thakur
,
Tien-Lin
Lee
,
Jonathan D.
Major
Diamond Proposal Number(s):
[34642]
Open Access
Abstract: The evolution of Sb2Se3 heterojunction devices away from CdS electron transport layers (ETL) to wide bandgap metal oxide alternatives is a critical target in the development of this emerging photovoltaic material. Metal oxide ETL/Sb2Se3 device performance has historically been limited by relatively low fill factors, despite offering clear advantages with regards to photocurrent collection. In this study, TiO2 ETLs are fabricated via direct current reactive sputtering and tested in complete Sb2Se3 devices. A strong correlation between TiO2 ETL processing conditions and the Sb2Se3 solar cell device response under forward bias conditions is observed and optimized. Numerical device models support experimental evidence of a spike-like conduction band offset, which can be mediated, provided a sufficiently high conductivity and low interfacial defect density can be achieved in the TiO2 ETL. Ultimately, a SnO2:F/TiO2/Sb2Se3/P3HT/Au device with the reactively sputtered TiO2 ETL delivers an 8.12% power conversion efficiency (η), the highest TiO2/Sb2Se3 device reported to-date. This is achieved by a substantial reduction in series resistance, driven by improved crystallinity of the reactively sputtered anatase-TiO2 ETL, whilst maintaining almost maximum current collection for this device architecture.
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Jun 2024
|
|
I11-High Resolution Powder Diffraction
|
Open Access
Abstract: The augmentation of photocatalytic activity in layered perovskite oxides via the integration of graphene-like materials presents a promising pathway for the optimization of solar energy conversion. The electron-rich nature of graphene, coupled with its high electron conductivity, functions as an effective photosensitizer, thereby enhancing visible light harvesting. In this investigation, we have, for the first time, assembled ultrathin exfoliated Dion–Jacobson perovskite layers with reduced graphene oxide (rGO) layers, resulting in a high surface area layered nanocomposite, achieved through a tailored electrostatic approach. To further refine the electron properties of the layered perovskite–reduced graphene oxide composites, we have explored the use of various lanthanides as A-site cations in the Dion–Jacobson perovskites, including LaNb2O7 (LNO), PrNb2O7 (PNO), and NdNb2O7 (NNO). The synthesized composites demonstrate exceptional performance in photocatalytic H2 production, with rGO/NNO exhibiting the highest activity, achieving a hydrogen evolution rate (HER) of 835 μmol g−1 under light illumination, attributable to optimal interfacial effects. Our experimental and theoretical analyses indicate that hydrogen production is predominantly influenced by the A-site cation charge density at the materials' interface, as dictated by the charge transfer dynamics. This research potentially contributes to the comprehension and enhancement of photocatalytic processes for applications in solar energy conversion.
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Jun 2024
|
|
B18-Core EXAFS
|
Diamond Proposal Number(s):
[29271]
Open Access
Abstract: Photocatalytic CO2 reduction, including reaction rate, product selectivity, and longevity, is highly sensitive to the coordination structure of the catalytic active sites, and the precise design of the active site remains a challenge in heterogeneous catalysts. Herein, we report on the modulation of the coordination structure of MNx-type active sites (M = Co or Ni; x = 4 or 5) anchored on a periodic mesoporous organosilica (PMO) support to improve photocatalytic CO2 reduction. The PMO was functionalized with pendant 3,6-di(2′-pyridyl)pyridazine (dppz) groups to allow immobilization of molecular Co and Ni complexes with polypyridine ligands. A comparative analysis of CO2 photoreduction in the presence of an organic photosensitizer (4CzIPN, 1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene) and a conventional [Ru(bpy)3]Cl2 sensitizer revealed strong influence of the coordination environment on the catalytic performance. CoN5-PMO demonstrated a superior CO2 photoreduction activity than the other materials and displayed a cobalt-based turnover number (TONCO) of 92 for CO evolution at ∼75% selectivity after 3 h irradiation in the presence of 4CzIPN. The hybrid CoN5-PMO catalyst exhibited better activity than its homogeneous [CoN5] counterpart, indicating that the heterogenization promotes the formation of isolated active sites with improved longevity and faster catalytic rate.
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Jun 2024
|
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I13-1-Coherence
|
Kieran W. P.
Orr
,
Jiecheng
Diao
,
Krishanu
Dey
,
Madsar
Hameed
,
Milos
Dubajic
,
Hayley L.
Gilbert
,
Thomas A.
Selby
,
Szymon J.
Zelewski
,
Yutong
Han
,
Melissa R.
Fitzsimmons
,
Bart
Roose
,
Peng
Li
,
Jiadong
Fan
,
Huaidong
Jiang
,
Joe
Briscoe
,
Ian K.
Robinson
,
Samuel D.
Stranks
Diamond Proposal Number(s):
[31362]
Open Access
Abstract: Strain is an important property in halide perovskite semiconductors used for optoelectronic applications because of its ability to influence device efficiency and stability. However, descriptions of strain in these materials are generally limited to bulk averages of bare films, which miss important property-determining heterogeneities that occur on the nanoscale and at interfaces in multilayer device stacks. Here, we present three-dimensional nanoscale strain mapping using Bragg coherent diffraction imaging of individual grains in Cs0.1FA0.9Pb(I0.95Br0.05)3 and Cs0.15FA0.85SnI3 (FA = formamidinium) halide perovskite absorbers buried in full solar cell devices. We discover large local strains and striking intragrain and grain-to-grain strain heterogeneity, identifying distinct islands of tensile and compressive strain inside grains. Additionally, we directly image dislocations with surprising regularity in Cs0.15FA0.85SnI3 grains and find evidence for dislocation-induced antiphase boundary formation. Our results shine a rare light on the nanoscale strains in these materials in their technologically relevant device setting.
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May 2024
|
|
I09-Surface and Interface Structural Analysis
|
Diamond Proposal Number(s):
[30357]
Open Access
Abstract: Novel lithium-ion battery electrolytes often exhibit poor electrochemical stability against typical commercial layered oxide and graphite electrodes. Pre-passivating the electrodes prior to cell assembly with an electrically insulating, ionically conductive solid-electrolyte interphase (SEI) is one innovative strategy for stabilising systems with otherwise unusable electrolytes. Here, methyl(2,2,2-trifluoroethyl) carbonate (FEMC), a promising non-flammable electrolyte solvent that is generally unstable against graphite, is utilised after pre-passivation of electrodes with a state-of-the-art carbonate-based electrolyte. A significant improvement in performance is observed compared with the untreated electrodes. Hard X-ray photoelectron spectroscopy was used to probe the interphase layer composition.
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Apr 2024
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