I07-Surface & interface diffraction
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Ehsan
Rezaee
,
Dimitar
Kutsarov
,
Esther Y.-H.
Hung
,
Benjamin M.
Gallant
,
Weidong
Xu
,
Yukun
Guo
,
Apostolos
Panagiotopoulos
,
George
Koutsourakis
,
Fernando A.
Castro
,
Samuel D.
Stranks
,
Henry J.
Snaith
,
S. Ravi P.
Silva
Diamond Proposal Number(s):
[36427]
Abstract: Commercialisation of perovskite photovoltaics (PV) hinges on scalable, environmentally responsible manufacturing; a challenge compounded by the widespread use of toxic solvents in current ink formulations. Here, we introduce a significantly reduced toxicity (SRT) solvent system for methylammonium lead iodide (MAPbI3) perovskite inks, specifically engineered for room-temperature, gas blowing assisted bar coating. Our formulation, based on ethanol and 2-methyltetrahydrofuran (2MeTHF) with a minimal fraction of dimethyl sulfoxide (DMSO), enables rapid crystallisation under mild thermal conditions following deposition, ensuring compatibility with both rigid and flexible substrates. This approach delivers uniform, defect-free perovskite films across large areas, validated through multi-scale characterisation techniques. Leveraging this SRT ink, we fabricate monolithically interconnected mini-modules (active area: 11.5 cm²) using a laser-based P1–P4 scribing process, achieving power conversion efficiencies (PCEs) exceeding 18%, among the highest reported for green, scalable perovskite processing. Performance gains are further enhanced by integrating bar-coated self-assembled monolayers (SAMs) as hole transport layers (HTLs), demonstrating industrial viability without compromising efficiency. Beyond device metrics, this work establishes a new sustainability benchmark by eliminating hazardous solvents and aligning with green chemistry principles, including low toxicity, biodegradability, and reduced environmental persistence. Our findings represent a critical step toward high-throughput, eco-friendly fabrication of perovskite solar modules, bridging the gap between laboratory innovation and industrial deployment.
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Dec 2026
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I10-Beamline for Advanced Dichroism - scattering
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Duncan
Miertschin
,
Sundar
Kunwar
,
Balaram
Regmi
,
Poshan
Kandel
,
Sanjib
Thapa
,
Davis
Crater
,
Luca
Basso
,
Adam
Dodson
,
Zheng
Gai
,
Lide
Yao
,
Yu-Wei
Chen
,
Peter
Bencok
,
Armin
Kleibert
,
Yen-Lin
Huang
,
Andy
Mounce
,
Paul G.
Kotula
,
Sebastiaan
Van Dijken
,
Alessandro R.
Mazza
,
Thomas Z.
Ward
,
Nick
Shepelin
,
Alan
Farhan
Diamond Proposal Number(s):
[40992]
Open Access
Abstract: Multiferroics that combine ferroelectricity and magnetic order are attractive for electronic and spintronic technologies, yet chemical disorder that promotes relaxor ferroelectricity usually suppresses long-range magnetic order. Here, we report entropy-stabilized relaxor multiferroicity in epitaxial hexagonal (Tb0.2Dy0.2Ho0.2Lu0.2Yb0.2)FeO3 thin films. Structural, magnetic, dielectric, and synchrotron spectroscopic measurements show the coexistence of relaxor ferroelectricity and long-range ferromagnetic order. We find that improper ferroelectricity remains robust against A-site configurational disorder, while the Fe sublattice preserves magnetic exchange. This separation of the microscopic origins of the polar and magnetic responses enables chemically disordered multiferroicity. Our results establish entropy engineering in hexagonal ferrites as a route toward multifunctional oxide thin films and provide a general design strategy for high-entropy multiferroics.
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Sep 2026
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I09-Surface and Interface Structural Analysis
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Eric S. A.
Goerlitzer
,
Zijia
Wu
,
Angus
Crookes
,
Shu
Hu
,
Rakesh
Arul
,
Sarah M.
Sibug-Torres
,
Bart
De Nijs
,
Reshma R.
Rao
,
Mary P.
Ryan
,
Angela
Demetriadou
,
Jeremy J.
Baumberg
Diamond Proposal Number(s):
[34784]
Open Access
Abstract: Controlling redox reactions at the atomic scale is key to enabling next-generation low-power memristive and neuromorphic devices. Ultrathin metallic layers, such as atomic monolayer palladium (Pd), offer tunable redox behavior well suited for switchable components in nanoscale electronics. Here, we present an in situ plasmonic-electrochemical platform that probes redox processes within subnanometer gaps using a nanoparticle-on-mirror (NPoM) geometry. Atomically thin Pd layers are grown by underpotential deposition, and their redox is monitored via surface enhanced Raman spectroscopy, revealing reversible transformations between metallic and dielectric Pd redox states. This confined plasmonic cavity enhances sensitivity to vibrational and electronic changes, allowing nondestructive optical readout of redox switching behaviors. By reducing the active switching volume to the monolayer limit while maintaining precise geometric control, this work establishes a powerful platform for probing redox dynamics at the atomic scale and points toward highly energy-efficient nanoswitches based on redox-active ultrathin materials.
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Sep 2026
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B07-B1-Versatile Soft X-ray beamline: High Throughput ES1
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Paul
Llontop
,
Mario
Hanser
,
Matthew
Wright
,
Soumyajit
Maitra
,
Eloy J.
Marcelis
,
Jana-Isabelle
Polzin
,
Martin
Bivour
,
David C.
Grinter
,
Pilar
Ferrer
,
Iris C. G.
Van Den Bosch
,
Christoph
Baeumer
,
Ruy S.
Bonilla
,
Armin
Richter
,
Monica
Morales‐masis
Diamond Proposal Number(s):
[40267]
Open Access
Abstract: The development of In-free transparent conductive oxides (TCOs) is essential for sustainable photovoltaics. For undoped tin oxide (SnOx), achieving high conductivity requires precise control over intrinsic defect chemistry. This work explores the impact of deposition pressure and oxygen stoichiometry on the electrical and optical properties of SnOx films grown by pulsed laser deposition (PLD). We identify a narrow conductivity window achieved at oxygen pressures between 0.015 and 0.020 mbar, beyond which a substantial drop in conductivity is observed. Within this optimal window, the SnOx films exhibit a 3-fold mobility enhancement after 300°C air annealing, despite preserving an amorphous phase. This improvement is primarily attributed to the reduction of ionized impurity scattering, evidenced by a simultaneous decrease in free carrier density. To demonstrate functionality, the inherent soft-landing nature of PLD was exploited to preserve the passivation quality of textured tunnel oxide passivating contacts (TOPCon) silicon substrates, as implied open-circuit voltage (iVoc) mapping confirmed the absence of deposition-induced damage. Finally, we demonstrate the compatibility of this In-free TCO by fabricating proof-of-concept perovskite solar cells on textured SnOx/n-TOPCon substrates, achieving open-circuit voltage of 1.21 V. These results highlight the potential of SnOxfor integration as an interconnection layer in fully textured perovskite/Si tandem solar cells.
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Sep 2026
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Pratap
Pal
,
Xiaoxi
Deng
,
Gi‐yeop
Kim
,
Kyoungjun
Lee
,
Jheng-Cyuan
Lin
,
Prithwijit
Mandal
,
Jiangfeng
Yang
,
Paul
Steadman
,
Pascal
Manuel
,
Roger D.
Johnson
,
Si-Young
Choi
,
Paolo G.
Radaelli
,
Chang-Beom
Eom
Open Access
Abstract: The spin cycloid characteristic of noncollinear antiferromagnets offers significant potential for energy-efficient, magnon-mediated spintronic applications. Multiferroic BiFeO3 is among the most promising candidate materials because its antiferromagnetic order can be controlled by an electric field. However, in epitaxial BiFeO3 thin films, substrate clamping and epitaxial strain modify the cycloidal magnetic structure while limiting efficient ferroelastic-ferroelectric switching. Here, we show that strain-released freestanding BiFeO3 membranes overcome these limitations. Compared with substrate-clamped epitaxial thin films, a 100-nm-thick freestanding membrane exhibits ≈50% faster electric-field-driven ferroelectric switching and a spatially uniform, bulk-like single spin cycloid, as revealed by resonant elastic X-ray scattering. In contrast, the epitaxial thin film exhibits an expanded cycloid periodicity and slower ferroelectric switching dynamics, reflecting the influence of substrate-induced strain. Freestanding BiFeO3 membranes therefore overcome substrate-induced constraints by simultaneously restoring the intrinsic bulk-like spin cycloid and enabling substantially faster ferroelectric switching. This combination of robust noncollinear antiferromagnetic order and efficient electric-field switching establishes freestanding BiFeO3 membranes as a promising magnetoelectric platform for low-power magnonic and spintronic technologies, while enabling heterogeneous integration with Si-based devices.
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Aug 2026
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Optics
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Open Access
Abstract: The precise exploitation and efficient control of residual stresses are crucial for the development of high-performance thin-film optics. Multi-beam optical sensors (MOS) have been widely used for in situ residual stress measurements; however, this only provides information on the average residual stress at a single position. To overcome this limitation, speckle-based curvature optical metrology (SCOM) has been implemented at the multilayer deposition system (MDS) at Diamond Light Source. SCOM delivers two-dimensional curvature mapping, which has enabled direct visualization of the variation of spatial residual stress and substrate deformation for the first time. Benchmarking of SCOM measurements against MOS reveals excellent agreement in the extracted curvature for a deformable mirror. Importantly, SCOM offers a significantly larger dynamic range, allowing accurate measurements under the extreme curvature conditions that are frequently encountered in thick, high-residual stress films. This approach was also used to evaluate the residual stress evolution of a range of important materials, including Mo, Si and WSi2, which have been systematically investigated across varying deposition thicknesses and working pressures.
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Aug 2026
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I09-Surface and Interface Structural Analysis
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Leyi
Loh
,
Han
Yan
,
Lixin
Liu
,
Yuan
Chen
,
Esther Lilian
Gray
,
Kamal Kumar
Paul
,
Deepnarayan
Biswas
,
Tien-Lin
Lee
,
Takashi
Taniguchi
,
Kenji
Watanabe
,
Mauro
Brotons-Gisbert
,
Yan
Wang
,
Manish
Chhowalla
Diamond Proposal Number(s):
[38012, 39914, 38086]
Open Access
Abstract: Unintentional doping from dielectrics can impact the electronic properties of two-dimensional transition metal dichalcogenide (2D TMD) semiconductors. Our recent work shows that high-dielectric-constant (k) ZrO2 is an electrostatically inert dielectric for 2D MoS2, supported by X-ray spectroscopy (XPS) and electrical measurements. Here, we expand this work through gate-controlled photoluminescence (PL) of monolayer MoS2 placed on different substrates. MoS2 on ZrO2 exhibits a low carrier concentration, indicated by a small trion-to-exciton ratio (X–/X0) of 0.5, similar to those on high-quality hBN. At a high electrostatic doping of ∼1013 cm–2, MoS2 on high-k ZrO2 reveals a slight exponential dependence of X–/X0 versus carrier concentration, while MoS2 on SiO2 shows strong exponential characteristics even at low gating (1012 cm–2) due to substantial electron doping from substrate-induced disorder tail states. Our findings provide insights into the doping mechanisms in industry-compatible amorphous dielectrics and evaluate their potential for scalable optoelectronic devices.
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Aug 2026
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I06-Nanoscience (XPEEM)
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Diamond Proposal Number(s):
[38242]
Open Access
Abstract: We report the evolution of the antiferromagnetic domain structure of epitaxial La0.45Sr0.55MnO3 (LSMO) ultrathin films with thickness in the range from 5–50 unit cells (uc), using x-ray photoemission electron microscopy (XPEEM). While the 5 uc thick LSMO shows no magnetic contrast down to ∼80K, thicker films display a multidomain antiferromagnetic configuration with a nonmonotonic variation in the characteristic domain size from 0.3 µm at 10 uc, to 3–5 µm at 15–16 uc and 1 µm for 50 uc. Post-growth annealing is found not to impact strongly the magnetic domain state. In contrast, for a 15 uc film grown on a substrate characterized by large atomic steps (∼1µm), we observe much larger antiferromagnetic domains and the presence of net magnetic moment in the form of stripes with alternating contrast, assigned to the signal from the top uncompensated spins of the A-type antiferromagnetic state of LSMO. From the combined antiferromagnetic domain structure and the net magnetic moment contrast, we determine the exact orientation of the Néel vector, including at domain walls. We describe the antiferromagnetic domain size distribution in terms of interface and bulk contributions to the density of defects that pin the antiferromagnetic domain walls and which determine the equilibrium domain configuration. Our results demonstrate the impact of thickness and defects on the antiferromagnetic domain size and constitute a stepping stone in controlling the antiferromagnetic domain state required for oxide antiferromagnetic device applications.
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Aug 2026
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I10-Beamline for Advanced Dichroism - scattering
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Diamond Proposal Number(s):
[38952]
Open Access
Abstract: High-entropy perovskite oxides offer a promising platform for tailoring magnetic functionality through compositional complexity; however, it remains unclear how targeted substitution of 4d transition metals modifies oxygen-mediated electronic structure and element-specific magnetic interactions. To address this question, we investigate the effect of Mo and Ru substitution on the electronic structure and magnetism of high-entropy perovskite oxide thin films using O K-edge and transition-metal L-edge X-ray absorption spectroscopy, X-ray magnetic circular dichroism (XMCD), and X-ray linear dichroism. O K-edge spectra reveal that Ru enhances O 2p–metal d hybridization, whereas Mo modifies charge distribution and local exchange pathways within the transition-metal sublattice. Multiplet analysis shows that Mn and Ni retain stable Mn4+ and Ni2+ states, while Co acts as the primary charge-compensation reservoir through changes in the Co2+/Co3+ ratio. Temperature-dependent XMCD demonstrates that these substitutions selectively reshape the magnetic exchange network, redistributing spin polarization among the constituent elements. Quantitative XMCD sum-rule analysis reveals that Mo substitution produces the highest reconstructed total magnetic moment across the measured temperature range, reaching values at low temperature that are nearly an order of magnitude larger than those observed in the Ru-containing compositions. These results establish a composition-driven strategy for tuning covalency, charge redistribution, and the balance between localized and itinerant magnetism in high-entropy oxide thin films, providing a pathway toward the design of tunable spintronic and multifunctional oxide materials.
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Aug 2026
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I21-Resonant Inelastic X-ray Scattering (RIXS)
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Xiaoyang
Chen
,
Wenliang
Zhang
,
Fei
Peng
,
Ting
Cui
,
Guangdi
Zhou
,
Zezhong
Li
,
Jaewon
Choi
,
Lizhi
Xu
,
Yiu-Fung
Chiu
,
Stefano
Agrestini
,
Sahil
Tippireddy
,
Haoliang
Huang
,
Heng
Wang
,
Xianfeng
Wu
,
Peng
Li
,
Jin-Feng
Jia
,
Mirian
Garcia-Fernandez
,
Yi
Lu
,
Er-Jia
Guo
,
Qi-Kun
Xue
,
Zhuoyu
Chen
,
Donglai
Feng
,
Ke-Jin
Zhou
Diamond Proposal Number(s):
[42637]
Open Access
Abstract: The recent discovery of Ruddlesden-Popper (RP) nickelate thin-film superconductors has opened a new frontier in unconventional superconductivity. Its realization requires both compressive epitaxial strain and highly oxidative growth conditions, yet the microscopic pathway from the parent phase to the superconducting phase remains elusive. Here, X-ray absorption spectra and resonant inelastic X-ray scattering are employed to track this evolution by independently tuning strain and oxygen content in (La,Pr)3Ni2O7 − δ thin films. We uncover a remarkable two-step narrative. First, signatures of delocalization emerge: Spectral weight transfers from a “Upper Hubbard”-like peak to the hole-like peak associated with O 2pz state, and in parallel, the initially localized Ni
orbital becomes more itinerant followed by the broadening and weakening of dd orbital excitations. Second, as itinerancy increases, long-range spin-density-wave (SDW) order is suppressed in both intensity and correlation length, indicating direct competition with superconductivity. Yet, short-range magnons persist: they become damped but their bandwidth stays unchanged. Our results paint a coherent picture that both strain and oxygenation drive the RP bilayer nickelates towards the superconducting instability, where the O 2pz and Ni
orbitals become delocalized. Concomitantly, the long-range magnetic order loses coherence and gets suppressed. These findings establish an orbital-selective route to RP nickelate superconductivity, in which the emergence and progressive delocalization of the interlayer
-2pz-
channel and the robust short-range magnons upon the melting of SDW order are prerequisites, providing strong constraints for theory and the roadmap for designing nickelate superconductors.
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Aug 2026
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