I19-Small Molecule Single Crystal Diffraction
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Milos
Dubajic
,
James R.
Neilson
,
Johan
Klarbring
,
Xia
Liang
,
Stephanie A.
Bird
,
Kirrily C.
Rule
,
Josie E.
Auckett
,
Thomas A.
Selby
,
Ganbaatar
Tumen-Ulzii
,
Yang
Lu
,
Young-Kwang
Jung
,
Cullen
Chosy
,
Zimu
Wei
,
Yorrick
Boeije
,
Martin V.
Zimmermann
,
Andreas
Pusch
,
Leilei
Gu
,
Xuguang
Jia
,
Qiyuan
Wu
,
Julia C.
Trowbridge
,
Eve M.
Mozur
,
Arianna
Minelli
,
Nikolaj
Roth
,
Kieran W. P.
Orr
,
Arman
Mahboubi Soufiani
,
Simon
Kahmann
,
Irina
Kabakova
,
Jianning
Ding
,
Tom
Wu
,
Gavin J.
Conibeer
,
Stephen P.
Bremner
,
Michael P.
Nielsen
,
Aron
Walsh
,
Samuel D.
Stranks
Diamond Proposal Number(s):
[33123]
Open Access
Abstract: Lead halide perovskites have emerged as promising materials for solar energy conversion and X-ray detection owing to their remarkable optoelectronic properties. However, the microscopic origins of their superior performance remain unclear. Here we show that low-symmetry dynamic nanodomains present in the high-symmetry average cubic phases, whose characteristics are dictated by the A-site cation, govern the macroscopic behaviour. We combine X-ray diffuse scattering, inelastic neutron spectroscopy, hyperspectral photoluminescence microscopy and machine-learning-assisted molecular dynamics simulations to directly correlate local nanoscale dynamics with macroscopic optoelectronic response. Our approach reveals that methylammonium-based perovskites form densely packed, anisotropic dynamic nanodomains with out-of-phase octahedral tilting, whereas formamidinium-based systems develop sparse, isotropic, spherical nanodomains with in-phase tilting, even when crystallography reveals cubic symmetry on average. We demonstrate that these sparsely distributed isotropic nanodomains present in formamidinium-based systems reduce electronic dynamic disorder, resulting in a beneficial optoelectronic response, thereby enhancing the performance of formamidinium-based lead halide perovskite devices. By elucidating the influence of the A-site cation on local dynamic nanodomains, and consequently, on the macroscopic properties, we propose leveraging this relationship to engineer the optoelectronic response of these materials, propelling further advancements in perovskite-based photovoltaics, optoelectronics and X-ray imaging.
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Jun 2025
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I07-Surface & interface diffraction
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Jiawei
Chen
,
Kangyu
Ji
,
Linjie
Dai
,
Hengyang
Xiang
,
Zhongzheng
Yu
,
Affan N.
Iqbal
,
Jian
Wang
,
Xingyue
Ma
,
Renjun
Guo
,
Miguel
Anaya
,
Xiufeng
Song
,
Yang
Lu
,
Yu-Hsien
Chiang
,
Weijin
Li
,
Yalong
Shen
,
Xiyu
Luo
,
Alessandro
Mirabelli
,
Yuanzhuang
Cheng
,
Xinrui
Chen
,
Dongxin
Ma
,
Zhiyong
Fan
,
Yurong
Yang
,
Lian
Duan
,
Samuel D.
Stranks
,
Haibo
Zeng
Diamond Proposal Number(s):
[30575]
Open Access
Abstract: Traditional white light-emitting diodes operate by exciting phosphors using blue light-emitting diodes, leading to the absence of specific colour bands compared with the visible light region of the sunlight spectrum (400–780 nm), and excess blue light increases the risk of harmful effects on ecosystems and organisms. Here, we precisely design and regulate heterophase γ/δ-CsPb(I/Cl)3 at the nanoscale for uniform heterophase distribution, balanced flow of charges and tunable spectrum. Then, γ/δ-CsPb(I/Cl)3 directly excited by electricity shows full-spectrum white electroluminescence covering 400–780 nm with standard Commission Internationale de l’Eclairage coordinates of (0.33, 0.33), a Colour Rendering Index of 95, a Correlated Colour Temperature of 5829 K and a Delta u,v of −3 × 10−4, accompanied with balanced white light composition (Melanopic ratio = 1.004). The match indices of such five core indicators to standard sunlight reach 100%, 95% (97% for R9), 99.5%, 99.97% and 99.6%, respectively, far ahead of as-fabricated commercial white light-emitting diodes.
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Apr 2025
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I07-Surface & interface diffraction
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Diamond Proposal Number(s):
[32266]
Abstract: Organic solar cells (OSCs) are attracting significant attention due to their low cost, lightweight, and flexible nature. The introduction of nonfullerene acceptors (NFAs) has propelled OSC development into a transformative era. However, the limited availability of wide band gap polymer donors for NFAs poses a critical challenge, hindering further advancements. This study examines the role of developed wide band gap halogenated pyrrolo[3,4-c]pyrrole-1,3(2H,5H)-dione (PPD)-based polymers, in combination with the Y6 nonfullerene acceptor, in bulk heterojunction (BHJ) OSCs. We first focus on the electronic and absorbance modifications brought about by halogen substitution in PPD-based polymers, revealing how these adjustments influence the HOMO/LUMO energy levels and, subsequently, photovoltaic performance. Despite the increased Voc of halogenated polymers due to the optimal band alignment, power conversion efficiencies (PCEs) were decreased due to suboptimal blend morphologies. We second implemented PPD as a solid additive to PM6:Y6, forming ternary OSCs and further improving the PCE. The study provides a nuanced understanding of the interplay between molecular design, device morphology, and OSC performance and opens insights for future research to achieve an optimal balance between band alignment and favorable blend morphology for high-efficiency OSCs.
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Jan 2025
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I07-Surface & interface diffraction
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Matteo
Degani
,
Riccardo
Pallotta
,
Giovanni
Pica
,
Masoud
Karimipour
,
Alessandro
Mirabelli
,
Kyle
Frohna
,
Miguel
Anaya
,
Tianyu
Xu
,
Chang-Qi
Ma
,
Samuel D.
Stranks
,
Monica Lira
Cantù
,
Giulia
Grancini
Diamond Proposal Number(s):
[32266]
Open Access
Abstract: Interface engineering using self-assembled 2D perovskite interfaces is a consolidated route to efficient and durable perovskite solar cells. Whether the 2D perovskite forms a homogeneous conformal layer or is heterogeneously distributed on the surface, interface defects are passivated, leading to a general improvement in the device's open circuit voltage (VOC) and stability. Here, an innovative strategy is developed for manipulating the composition of the 2D/3D perovskite interface that results in the formation of a gradient halide distribution, which extends from the surface to the bulk. The use of a bromide-based 2D perovskite triggers a progressive Br/I exchange, affecting not only the surface but also the perovskite underneath. As a result, not only the device VOC improve, as expected, but also the photogenerated current is boosted, leading to a device efficiency of up to 24.4%. Such mixed halide gradient effectively passivates surface and bulk defects making the perovskite active layer more efficient and robust, as demonstrated by the superior device stability showing zero losses in performances upon 36 days (more than 800 h) test in outdoor conditions, those ones relevant for a marketable product.
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Dec 2024
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I14-Hard X-ray Nanoprobe
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Kyle
Frohna
,
Cullen
Chosy
,
Amran
Al-Ashouri
,
Florian
Scheler
,
Yu-Hsien
Chiang
,
Milos
Dubajic
,
Julia E.
Parker
,
Jessica M.
Walker
,
Lea
Zimmermann
,
Thomas A.
Selby
,
Yang
Lu
,
Bart
Roose
,
Steve
Albrecht
,
Miguel
Anaya
,
Samuel D.
Stranks
Diamond Proposal Number(s):
[30427, 31964]
Open Access
Abstract: Microscopy provides a proxy for assessing the operation of perovskite solar cells, yet most works in the literature have focused on bare perovskite thin films, missing charge transport and recombination losses present in full devices. Here we demonstrate a multimodal operando microscopy toolkit to measure and spatially correlate nanoscale charge transport losses, recombination losses and chemical composition. By applying this toolkit to the same scan areas of state-of-the-art, alloyed perovskite cells before and after extended operation, we show that devices with the highest macroscopic performance have the lowest initial performance spatial heterogeneity—a crucial link that is missed in conventional microscopy. We show that engineering stable interfaces is critical to achieving robust devices. Once the interfaces are stabilized, we show that compositional engineering to homogenize charge extraction and to minimize variations in local power conversion efficiency is critical to improve performance and stability. We find that in our device space, perovskites can tolerate spatial disorder in chemistry, but not charge extraction.
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Oct 2024
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B21-High Throughput SAXS
labSAXS-Offline SAXS and Sample Environment Development
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Diamond Proposal Number(s):
[29568, 30717, 30473]
Open Access
Abstract: The instability and limited scalability of halide perovskites hinder their long-term viability in applications as X-ray detectors. Here, we introduce a sol-gel ship-in-bottle approach to produce a monolithic perovskite@metal-organic framework (MOF) composite, combining the properties of the individual building blocks and enhancing density, robustness, and stability. By tuning seed particles below 100 nm, we achieve highly crystalline, dense composites with up to 40% perovskite loading. Structural and optical characterization unveils perovskite nanocrystals forming within MOF mesopores, maximizing stability and preventing degradation, maintaining over 90% photoluminescence and structural integrity after weeks of exposure to humidity, heat, and solvents. Proposed as an innovative class of scintillator, these monolithic perovskite@MOFs attenuate X-rays efficiently and exhibit outstanding stability under high radiation doses equivalent to 110,000 typical chest X-rays, with a radioluminescence lifetime of 10 ns, outperforming commercial scintillators. This approach offers vast potential for developing high-performance, cost-effective, and stable devices for radiation detection and other optoelectronic applications.
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Sep 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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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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E02-JEM ARM 300CF
I07-Surface & interface diffraction
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Affan N.
Iqbal
,
Kieran W. P.
Orr
,
Satyawan
Nagane
,
Jordi Ferrer
Orri
,
Tiarnan A. S.
Doherty
,
Young-Kwang
Jung
,
Yu-Hsien
Chiang
,
Thomas A.
Selby
,
Yang
Lu
,
Alessandro J.
Mirabelli
,
Alan
Baldwin
,
Zher Ying
Ooi
,
Qichun
Gu
,
Miguel
Anaya
,
Samuel D.
Stranks
Diamond Proposal Number(s):
[32007]
Open Access
Abstract: Halide perovskites are excellent candidate materials for use in solar cell, LED, and detector devices, in part because their composition can be tuned to achieve ideal optoelectronic properties. Empirical efficiency optimisation has led the field towards compositions rich in FA (formamidinium) on the A-site and I on the X-site, with additional small amounts of MA (methylammonium) or Cs A-site cations and Br X-site anions. However, it is not clear how and why the specific compositions of alloyed, i.e., mixed component, halide perovskites relate to photo-stability of the materials. Here, we combine synchrotron grazing incidence wide-angle x-ray scattering, photoluminescence, high-resolution scanning electron diffraction measurements and theoretical modelling to reveal the links between material structure and photostability. Namely, we find that increased octahedral titling leads to improved photo-stability that is correlated with lower densities of performance-harming hexagonal polytype impurities. Our results uncover the structural signatures underpinning photo-stability and can therefore be used to make targeted changes to halide perovskites, bettering the commercial prospects of technologies based on these materials.
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May 2024
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I13-1-Coherence
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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
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