I07-Surface & interface diffraction
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Chieh-Szu
Huang
,
Danbi
Kim
,
Wenyan
Yang
,
Yang
Lu
,
Robert J. E.
Westbrook
,
Huagui
Lai
,
Zimu
Wei
,
Chaeyeon
Lee
,
Fan
Fu
,
Neil C.
Greenham
,
Bo Ram
Lee
,
Samuel D.
Stranks
Diamond Proposal Number(s):
[32266]
Open Access
Abstract: Amphiphilic polymer conetworks (APCNs), composed of nanoscale phase-separated hydrophilic and hydrophobic domains, have recently attracted interest for passive photonic applications like wearable luminescent solar concentrators. Here, their utility is extended by integrating APCNs into the active layer of organic photovoltaics (OPVs), enabling the incorporation of down-conversion luminophores that are otherwise incompatible with conventional OPV architectures. The APCN scaffold confines hydrophilic luminophores within hydroxyl acrylate domains, while the hydrophobic PM6:Y6 bulk heterojunction (BHJ) resides in the polydimethylsiloxane domains. Luminophores are chosen for selective phase affinity and complementary absorption to the BHJ. Devices incorporating dicyanomethylene-4H-pyran (DCM) luminophores show enhanced photocurrent, with short-circuit current increasing from 25.7 to 27.3 mA cm−2, while maintaining an open-circuit voltage of 0.86 V. Transient absorption spectroscopy reveals delayed ground-state bleach in PM6 and Y6, consistent with efficient exciton replenishment via energy transfer from luminophores. Grazing-incidence wide-angle X-ray scattering shows that luminophore molecular planarity and dihedral angles influence BHJ packing via van der Waals interactions, impacting charge transport. This work presents a multifunctional approach to enhance optoelectronic devices by embedding functional moieties within APCNs, offering insights from photonic, optoelectronic, and structural perspectives and establishing APCNs as a versatile platform for next-generation device engineering.
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Nov 2025
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I07-Surface & interface diffraction
I15-Extreme Conditions
I19-Small Molecule Single Crystal Diffraction
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Yang
Lu
,
Young-Kwang
Jung
,
Milos
Dubajic
,
Xinjuan
Li
,
Shabnum
Maqbool
,
Qichun
Gu
,
Xinyu
Bai
,
Yorrick
Boeije
,
Xian Wei
Chua
,
Alessandro J.
Mirabelli
,
Taeheon
Kang
,
Lars
Sonneveld
,
Youcheng
Zhang
,
Thomas A.
Selby
,
Capucine
Mamak
,
Kan
Tang
,
Zhongzheng
Yu
,
Tianjun
Liu
,
Miguel
Anaya
,
Stephen
Barlow
,
Seth R.
Marder
,
Bruno
Ehrler
,
Caterina
Ducati
,
Richard H.
Friend
,
Samuel D.
Stranks
Diamond Proposal Number(s):
[32266, 38601, 30043, 33123, 36628, 38508]
Abstract: Halide perovskites exhibit superior optoelectronic properties but lack precise thickness and band offset control in heterojunctions, which is critical for modular multilayer architectures such as multiple quantum wells. We demonstrate vapor-phase, layer-by-layer heteroepitaxial growth exemplified by CsPbBr3 deposition on single crystals of PEA2PbBr4 (PEA: 2-phenylethylammonium). Angstrom-level thickness control and subangstrom smooth layers enable quantum-confined photoluminescence of CsPbBr3 from monolayer, bilayer, and through to bulk. The interfacial structure controls the electronic structure from a Cs‒PEA-terminated interface (type II heterojunction) to a PEA‒PEA-terminated interface (type I heterojunction), with a layer-tunable band offset shift exceeding 0.5 electron volts. Electron transfer from CsPbBr3 to PEA2PbBr4 for a type II Cs‒PEA heterojunction results in delayed electron-hole recombination beyond 10 microseconds. Precise quantum confinement control and large band offset tunability unlock perovskite heterojunctions as platforms for scalable, superlattice-based optoelectronic applications.
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Nov 2025
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E02-JEM ARM 300CF
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Dengyang
Guo
,
Thomas A.
Selby
,
Simon
Kahmann
,
Sebastian
Gorgon
,
Linjie
Dai
,
Milos
Dubajic
,
Terry
Chien-Jen Yang
,
Simon M.
Fairclough
,
Thomas
Marsh
,
Ian E.
Jacobs
,
Baohu
Wu
,
Renjun
Guo
,
Satyawan
Nagane
,
Tiarnan A. S.
Doherty
,
Kangyu
Ji
,
Cheng
Liu
,
Yang
Lu
,
Taeheon
Kang
,
Capucine
Mamak
,
Jian
Mao
,
Peter
Muller-Buschbaum
,
Henning
Sirringhaus
,
Paul A.
Midgley
,
Samuel D.
Stranks
Diamond Proposal Number(s):
[35894]
Open Access
Abstract: The high optoelectronic quality of halide perovskites makes them suitable for use in optoelectronic devices and, recently, in emerging quantum emission applications. Advancements in perovskite nanomaterials have led to the discovery of processes in which luminescence decay times are below 100 picoseconds, stimulating the exploration of even faster radiative rates for advanced quantum applications, which have only been realized in III–V materials grown using costly epitaxial growth methods. Here we discovered ultrafast quantum transients with timescales of around two picoseconds at low temperature in bulk formamidinium lead iodide films grown via scalable solution or vapour approaches. Using a multimodal strategy, combining ultrafast spectroscopy, optical and electron microscopy, we show that these transients originate from quantum tunnelling in nanodomain superlattices. The outcome of the transient decays, that is, photoluminescence, mirrors the photoabsorption of the states, with an ultranarrow linewidth at low temperature that can reach <2 nm (~4 meV). Localized correlation of the emission and structure reveals that the nanodomain superlattices are formed by alternating ordered layers of corner-sharing and face-sharing octahedra. This discovery opens new applications leveraging intrinsic quantum properties and demonstrates powerful multimodal approaches for quantum investigations.
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Oct 2025
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I14-Hard X-ray Nanoprobe
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Diamond Proposal Number(s):
[34086]
Open Access
Abstract: Compared with conventional laboratory-scale X-ray techniques, synchrotron based X-rays with higher brilliance and higher coherence allow for the investigation of various material properties with high spatial resolution. The microscopic behaviours of materials can be examined using the Hard X-ray Nanoprobe beamline (I14) at Diamond Light Source, which provides a 50 nm focused beam and has been successfully employed to identify nanoscale optoelectronic features in energy-harvesting materials such as halide perovskites that exhibit local heterogeneity. We have developed X-ray beam-induced current (XBIC) measurement capability at I14 to address the growing demand for operando analysis in energy-harvesting research. Here, we demonstrate that X-ray fluorescence (XRF)/XBIC multimodal measurements are feasible at I14 and apply these newly implemented techniques to study perovskite solar cells with various additive concentrations to understand the effect of the additive on nanoscale optoelectronic performance. This expanded operando characterization capability offers the possibility of monitoring nanometre-scale compositional variations and corresponding optoelectronic features of actual solar cell configurations.
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Sep 2025
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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
I09-Surface and Interface Structural Analysis
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Alessandro J.
Mirabelli
,
Birgit
Kammlander
,
Yang
Lu
,
Rahul Mahavir
Varma
,
Qichun
Gu
,
Karen
Radetzky
,
Thomas A.
Selby
,
Tianjun
Liu
,
Stefania
Riva
,
Zimu
Wei
,
Tien-Lin
Lee
,
Jonathan
Rawle
,
Hakan
Rensmo
,
Miguel
Anaya
,
Ute B.
Cappel
,
Samuel D.
Stranks
Diamond Proposal Number(s):
[30043, 32266, 30838, 33096]
Open Access
Abstract: To commercialize lead halide perovskites as light-emitting diodes (LEDs), the operational device lifetime needs to be drastically improved. For this to be achieved, an understanding of degradation behavior under bias is crucial. Herein, we perform operando measurements of the structural, chemical, and electronic changes using synchrotron-based grazing-incidence wide-angle X-ray scattering and hard X-ray photoelectron spectroscopy on full-stack deep blue mixed bromide/chloride lead halide perovskite LEDs. While a clear drop in optoelectronic performance is recorded under electrical bias, the accompanying X-ray scattering data reveals only minor changes in structural properties. However, photoelectron spectroscopy reveals substantial chemical changes at the electron-injecting interface after bias is applied, including the formation of unwanted metallic lead and a new chlorine species that is not in the perovskite structure. These operando approaches give important structural and interfacial perspectives to reveal the degradation mechanisms in these LEDs and highlight the need to address the top electron-injecting interface to realize step-changes in operational stability.
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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
|
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
|
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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