I07-Surface & interface diffraction
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Nattawut
Kamjam
,
Kanokwan
Choodam
,
Noppawit
Sukpan
,
Tanakorn
Kittikool
,
Chaowaphat
Seriwattanachai
,
Sirawit
Kamnoedmanee
,
Yue
Hu
,
Ratchadaporn
Supruangnet
,
Hideki
Nakajima
,
Anusit
Kaewprajak
,
Pisist
Kumnorkaew
,
Duangmanee
Wongratanaphisan
,
Pipat
Ruankham
,
Pasit
Pakawatpanurut
,
Pongsakorn
Kanjanaboos
Open Access
Abstract: Perovskite solar cells (PSCs) offer a promising pathway towards low-cost, high-efficiency photovoltaics. However, conventional PSCs require at least two charge transport layers (ETL and HTL), increasing fabrication complexity and cost. ETL-free PSCs present a cost-effective alternative but suffer from energy-level misalignment at the perovskite/electrode interface, leading to charge recombination and efficiency losses. Recent studies have employed interfacial modifications to improve energy alignment, yet these still retain multilayer structures. In this work, we developed a simplified, fully ETL- and HTL-free PSC architecture (FTO/Cs0.1 (FA0.88MA0.12)Pb(I0.7Br0.3)(CsFAMA 1.7 eV)/Phenethyl ammonium iodide (PEAI)/Carbon) via introducing 1-ethyl-3-methylimidazolium acetate (EMIM Ac) into the perovskite layer, causing better energy level alignment, reduced trap density, and improved crystallinity. The fully striped-down structure surprisingly achieves an efficiency of 12.53% under 1,000 lux, sufficient to be a battery replacement for indoor energy frugal IoTs, while lowering production costs by minimizing layers and processing steps. Our findings highlight ultra-lean PSCs, which comprise of only perovskite and two electrodes, demonstrating the simplified solar cell structure to date, which is fully capable of powering indoor IoT applications.
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Apr 2026
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I07-Surface & interface diffraction
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Diamond Proposal Number(s):
[35227]
Open Access
Abstract: Organic semiconductors offer a long-spin coherence time and diffusion length due to the weak spin–orbit and hyperfine interactions in these materials. However, in commonly used lateral field-effect transistor structures, it is challenging to define device dimensions comparable to the spin diffusion length. On the other hand, vertical structures, offering smaller device dimensions, are facing issues due to the low carrier mobilities in the vertical dimension. Here, we investigate spin relaxation in rubrene thin films with a triclinic phase, which are doped with C60F48 by coevaporation. The doping provides an efficient way to generate charge carriers, and their high out-of-plane mobility should enhance long-spin diffusion. Using electron-spin resonance, we show that the spin relaxation is governed by the interaction with the dopant counterions and estimate the spin diffusion length to be ∼200 nm. This is comparable to the film thickness, which should make such doped rubrene films an attractive system for spintronic device applications.
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Mar 2026
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I07-Surface & interface diffraction
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Yuyun
Yao
,
Mustafeez Bashir
Shah
,
Wanpeng
Lu
,
Xian'E
Li
,
Rushil
Vasant
,
Zeinab
Hamid
,
Keren
Ai
,
Junfu
Tian
,
Maryam
Alsufyani
,
Jonathan
Rawle
,
Malina
Gaşpar
,
Qingpei
Wan
,
Rachael
Found
,
Wesley
Chen
,
Tomaž
Kotnik
,
Thuc-Quyen
Nguyen
,
Achilleas
Savva
,
James
Durrant
,
Iain
Mcculloch
Diamond Proposal Number(s):
[39430]
Open Access
Abstract: The development of organic electrochemical transistors (OECTs) critically depends on the design and characterization of mixed-conducting, high-performance conjugated polymers (CPs) as channel materials, particularly for n-type OECTs. In this study, we present a novel strategy to enhance the OECT performance of a semiconducting polymer film via a postdeposition ester pyrolysis of thermally cleavable side chains, thus facilitating ion incorporation and transport within the bulk. Our approach relies on the synthesis of a high glass-transition, rigid-rod polymer, able to withstand the pyrolysis temperature without deformation and maintain the voids formed from the pyrolysis reaction which removes the thermally cleavable ester side chains. After side-chain cleavage, the resulting film exhibits increased porosity, hydrophilicity, and crystallinity. By creating bulk porosity in thin films via this approach, ion diffusion is enhanced, resulting in a superior μC* figure of merit up to 158.85 F cm–1 V–1 s–1, and a corresponding increase in normalized transconductance (31.67 S cm–1). In addition, the device switching speed and long-term stability are also observed to increase, further demonstrating the benefit of nanoscale porosity for mixed conductivity semiconductors.
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Feb 2026
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I07-Surface & interface diffraction
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Xinyi
Shen
,
Wing Tung
Hui
,
Shuaifeng
Hu
,
Fengning
Yang
,
Junke
Wang
,
Jin
Yao
,
Atse
Louwen
,
Bryan Siu Ting
Tam
,
Lirong
Rong
,
David P.
Mcmeekin
,
Kilian
Lohmann
,
Qimu
Yuan
,
Matthew C.
Naylor
,
Manuel
Kober-Czerny
,
Seongrok
Seo
,
Philippe
Holzhey
,
Karl-Augustin
Zaininger
,
M. Greyson
Christoforo
,
Perrine
Carroy
,
Vincent
Barth
,
Fion Sze Yan
Yeung
,
Nakita K.
Noel
,
Michael
Johnston
,
Yen-Hung
Lin
,
Henry J.
Snaith
Diamond Proposal Number(s):
[39532]
Open Access
Abstract: Vacuum-based deposition is a scalable, solvent-free industrial method ideal for uniform coatings on complex substrates. However, all-vacuum-deposited perovskite solar cells fabricated by thermal evaporation trail solution-processed counterparts in efficiency and stability due to film quality challenges, necessitating advancement and improved understanding. Here, we report a co-evaporation route for 1.67-eV wide-bandgap perovskites by introducing a PbCl2 co-source to optimize film quality. We promote perovskite formation with pronounced (100) ‘face-up’ orientation and deliver a certified all-vacuum-deposited solar cell with 18.35% efficiency (19.3% in the laboratory) for 0.25-cm2 devices (18.5% for 1-cm2 cells). These cells retain 80% of peak efficiency after 1,080 h under the ISOS-L-2 protocol. Leveraging operando hyperspectral imaging, we provide spatiotemporal spectral insight into halide segregation and trap-mediated recombination, correlating microscopic luminescence features with macroscopic device performance while distinguishing radiative from non-ideal recombination channels. We further demonstrate 27.2%-efficient 1-cm2 evaporated perovskite-on-silicon tandem cells and outdoor stability of all-vacuum-deposited tandems in Italy, retaining ~80% initial performance after eight months.
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Feb 2026
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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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I07-Surface & interface diffraction
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Zhongzheng
Yu
,
Yunzhou
Deng
,
Junzhi
Ye
,
Lars
Van Turnhout
,
Tianjun
Liu
,
Alasdair
Tew
,
Rakesh
Arul
,
Simon
Dowland
,
Yuqi
Sun
,
Xinjuan
Li
,
Linjie
Dai
,
Caterina
Ducati
,
Jeremy J.
Baumberg
,
Richard H.
Friend
,
Robert L. Z.
Hoye
,
Akshay
Rao
Diamond Proposal Number(s):
[32266]
Open Access
Abstract: Insulating nanomaterials have large energy gaps and are only electrically accessible under extreme conditions, such as high-intensity radiation and high temperature, pressure or voltage1,2. Lanthanide-doped insulating nanoparticles (LnNPs) are widely studied owing to their exceptional luminescence properties, including bright, narrow-linewidth, non-blinking and non-bleaching emission in the second near-infrared (NIR-II) range3,4. However, it has not been possible to electrically generate excited states in these insulating nanomaterials under low biases and, therefore, not possible to fabricate optoelectronic devices from these systems. Here we report an electrical excitation pathway to obtain emission from LnNPs. By forming LnNP@organic molecule nanohybrids, in which the recombination of electrically injected charges on the organic molecule is followed by efficient triplet energy transfer (TET) to the LnNP, it is possible to turn on LnNPs under a low operating bias. We demonstrate this excitation pathway in light-emitting diodes (LEDs), with low turn-on voltages of about 5 V, very narrow electroluminescence (EL) spectra and a peak external quantum efficiency (EQE) greater than 0.6% in the NIR-II window5. Our LnNP-based LEDs (LnLEDs) also allow for widely tunable EL properties, by changing the type and concentration of lanthanide dopants. These results open up a new field of hybrid optoelectronic devices and provide new opportunities for the electrically driven excitation sources based on lanthanide nanomaterials for biomedical and optoelectronic applications.
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Nov 2025
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I07-Surface & interface diffraction
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Diamond Proposal Number(s):
[35227]
Open Access
Abstract: Electron spin resonance can provide unique insights into charge transport processes in organic semiconductors in a regime in which charge motion determines spin relaxation. In particular, electrically detected magnetic resonance (EDMR) probes directly the changes in charge transport properties that are sensitive to magnetic resonance excitation. Here, we present a systematic study of continuous-wave EDMR on conjugated polymer field-effect transistors (FETs) that can be operated in both unipolar as well as ambipolar regimes. We show that, in addition to a narrow, electron-hole recombination-induced EDMR signal that can only be detected in the ambipolar regime, there is also a broad EDMR signal when devices are operated in both unipolar and ambipolar regions. We attribute this signal to a spin blockade mechanism induced when mobile carriers encounter trapped charges along the charge transport percolation pathways and study its dependence on biasing conditions and temperature. The spin-blockade EDMR signature is also observed in conjugated polymer FETs that exhibit only unipolar operation. Our findings show that EDMR provides a powerful technique to study the role of spin blockade and bipolaron formation on the charge transport properties of a wide range of conjugated polymers.
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Oct 2025
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I07-Surface & interface diffraction
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Diamond Proposal Number(s):
[36553]
Open Access
Abstract: Superlattices of lead chalcogenide colloidal quantum dots hold promise to revolutionise the field of infrared optoelectronics due to their unique combination of optical and transport properties. However, the main challenge remains to form a homogeneous thin-film with long-range order avoiding cracking upon ligand exchange. To overcome these issues, we introduce an approach where external lateral pressure is applied during the self-assembly and ligand exchange, thus avoiding the formation of cracks due to volume shrinking. The formed monolayer superlattices are crack-free over several millimetres square. Transport measurements in an ionic gel-gated field-effect transistor reveal that increasing the external pressure during the superlattice formation leads to higher electron mobilities above 25 cm2V−1s−1 thanks to better compactness, high ordering, and a higher number of nearest neighbours. These results demonstrate that colloidal quantum dot superlattices with high charge mobility can be fabricated over large areas with important implications for technological applications.
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Oct 2025
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I07-Surface & interface diffraction
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Josephine L.
Surel
,
Pietro
Caprioglio
,
Joel A.
Smith
,
Akash
Dasgupta
,
Francesco
Furlan
,
Charlie
Henderson
,
Fengning
Yang
,
Benjamin M.
Gallant
,
Seongrok
Seo
,
Alexander
Knight
,
Manuel
Kober-Czerny
,
Joel
Luke
,
David P.
Mcmeekin
,
Alexander I.
Tartakovskii
,
Ji-Seon
Kim
,
Nicola
Gasparini
,
Henry J.
Snaith
Diamond Proposal Number(s):
[33462]
Open Access
Abstract: Performance losses in positive–intrinsic–negative architecture perovskite solar cells are dominated by nonradiative recombination at the perovskite/organic electron transport layer interface, which is particularly problematic for wider bandgap perovskites. Large endeavours have been dedicated to the replacement of fullerenes, which are the most commonly used class of electron transport layers, with limited success thus far. In this work, we demonstrate blending the fullerene derivatives [6,6]-phenyl C61 butyric acid methyl ester (PCBM) and indene-C60 bis-adduct (ICBA) as a thin interlayer between 1.77 eV bandgap perovskite and an evaporated C60 layer. By tuning the fullerene blend to a trace 2% by mass of PCBM in ICBA, we remarkably form an interlayer which features improved energetic alignment with the perovskite and the PCBM[thin space (1/6-em)]:[thin space (1/6-em)]ICBA fullerene mixture, together with a stronger molecular ordering and an order of magnitude higher electron mobility than either neat PCBM or ICBA. Additional molecular surface passivation approaches are found to be beneficial in conjunction with this approach, resulting in devices with 19.5% steady state efficiency, a fill factor of 0.85 and an open-circuit voltage of 1.33 V, which is within 10% of the radiative limit of the latter two device parameters for this bandgap. This work highlights the complex nonlinear energetic behaviour with fullerene mixing, and how control of the energetics and crystallinity of these materials is crucial in overcoming the detrimental recombination losses that have historically limited perovskite solar cells.
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Jul 2025
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