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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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B23-Circular Dichroism
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Diamond Proposal Number(s):
[29151]
Open Access
Abstract: Circular dichroism spectroscopy is a key probe of the structural and optical properties of chiral materials, however, commercial circular dichroism spectrometers are large, prohibitively expensive and rarely offer environmental control of the sample under test. Using Fresnel rhombs as inexpensive broadband quarter-wave plates, we demonstrate two novel, low-cost (<£2,000) and portable imaging systems controlled by our own bespoke open-source control software which are capable of spatially mapping the circular dichroism of chiral solid state films. By coupling these imaging systems with a temperature controlled stage, we show that we can rapidly identify the thermal processing conditions required to maximise circular dichroism in chiral solid state films by measuring circular dichroism in situ during thermal annealing of a sample under test. The accuracy and spatial resolution of these circular dichroism imagers are cross-compared against our previous studies using an existing circular dichroism imaging system at the Diamond Light Source and are shown to be in good agreement, with a sensitivity down to 250 mdeg and a spatial resolution of 100 μm.
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Jun 2024
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B23-Circular Dichroism
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Jessica
Wade
,
Francesco
Salerno
,
Rachel C.
Kilbride
,
Dong Kuk
Kim
,
Julia A.
Schmidt
,
Joel A.
Smith
,
Luc M.
Leblanc
,
Emma H.
Wolpert
,
Adebayo A.
Adeleke
,
Erin R.
Johnston
,
Jenny
Nelson
,
Tadashi
Mori
,
Kim E.
Jelfs
,
Sandrine
Heutz
,
Matthew J.
Fuchter
Diamond Proposal Number(s):
[29151]
Abstract: Chiral π-conjugated molecules bring new functionality to technological applications and represent an exciting, rapidly expanding area of research. Their functional properties, such as the absorption and emission of circularly polarized light or the transport of spin-polarized electrons, are highly anisotropic. As a result, the orientation of chiral molecules critically determines the functionality and efficiency of chiral devices. Here we present a strategy to control the orientation of a small chiral molecule (2,2′-dicyano[6]helicene) by the use of organic and inorganic templating layers. Such templating layers can either force 2,2′-dicyano[6]helicene to adopt a face-on orientation and self-assemble into upright supramolecular columns oriented with their helical axis perpendicular to the substrate, or an edge-on orientation with parallel-lying supramolecular columns. Through such control, we show that low- and high-energy chiroptical responses can be independently ‘turned on’ or ‘turned off’. The templating methodologies described here provide a simple way to engineer orientational control and, by association, anisotropic functional properties of chiral molecular systems for a range of emerging technologies.
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Oct 2022
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I12-JEEP: Joint Engineering, Environmental and Processing
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Diamond Proposal Number(s):
[16771]
Open Access
Abstract: An experimental technique is described for the collection of time-resolved X-ray diffraction information from a complete commercial battery cell during discharging or charging cycles. The technique uses an 80 × 80 pixel 2D energy-discriminating detector in a pinhole camera geometry which can be used with a polychromatic X-ray source. The concept was proved in a synchrotron X-ray study of commercial alkaline Zn–MnO2 AA size cells. Importantly, no modification of the cell was required. The technique enabled spatial and temporal changes to be observed with a time resolution of 20 min (5 min of data collection with a 15 min wait between scans). Chemical changes in the cell determined from diffraction information were correlated with complementary X-ray tomography scans performed on similar cells from the same batch. The clearest results were for the spatial and temporal changes in the Zn anode. Spatially, there was a sequential transformation of Zn to ZnO in the direction from the separator towards the current collector. Temporally, it was possible to track the transformation of Zn to ZnO during the discharge and follow the corresponding changes in the cathode.
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Dec 2020
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I07-Surface & interface diffraction
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Diamond Proposal Number(s):
[20426]
Open Access
Abstract: Simultaneous control over both the energy levels and Fermi level, a key breakthrough for inorganic electronics, has yet to be shown for organic semiconductors. Here, energy level tuning and molecular doping are combined to demonstrate controlled shifts in ionisation potential and Fermi level of an organic thin film. This is achieved by p-doping a blend of two host molecules, zinc phthalocyanine and its eight-times fluorinated derivative, with tunable energy levels based on mixing ratio. The doping efficiency is found to depend on host mixing ratio, which is explained using a statistical model that includes both shifts of the host’s ionisation potentials and, importantly, the electron affinity of the dopant. Therefore, the energy level tuning effect has a crucial impact on the molecular doping process. The practice of comparing host and dopant energy levels must consider the long-range electrostatic shifts to consistently explain the doping mechanism in organic semiconductors.
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Dec 2019
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I07-Surface & interface diffraction
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Diamond Proposal Number(s):
[18016, 20426]
Open Access
Abstract: We report on a method for fabricating balanced hole and electron transport in ambipolar organic field-effect transistors (OFETs) based on the co-evaporation of zinc-phthalocyanine (ZnPc) and its fluorinated derivative (F8ZnPc). The semiconducting behaviour of the OFET can be tuned continuously from unipolar p-type, with a hole mobility in the range of (1.7 ± 0.1) × 10−4 cm2/Vs, to unipolar n-type, with an electron mobility of (1.0 ± 0.1) × 10−4 cm2/Vs. Devices of the pristine ZnPc and F8ZnPc show a current on/off ratio of 105. By co-evaporating the p-type ZnPc with the n-type F8ZnPc, we fabricate ambipolar transistors and complementary-like voltage inverters. For the ambipolar devices, the optimum balance between the hole and electron mobilities is found for the blend of 1:1.5 weight ratio with hole and electron mobilities of (8.3 ± 0.2) × 10−7 cm2/Vs and (5.5 ± 0.1) × 10−7 cm2/Vs, respectively. Finally we demonstrate application of the ambipolar devices in a complementary-like voltage inverter circuit with the performance comparable to an inverter based on separate ZnPc and F8ZnPc OFETs.
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Mar 2019
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I07-Surface & interface diffraction
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Diamond Proposal Number(s):
[15486]
Abstract: The optoelectronic properties of blends of conjugated polymers and small molecules are likely to be affected by the molecular dynamics of the active layer components. We study the dynamics of regio-regular poly(3-hexylthiophene) (P3HT): phenyl-C61-butyric acid methyl ester (PCBM) blends using molecular dynamics (MD) simulation on time scales up to 50 ns and in a temperature range of 250-360K. First, we compare the MD results with quasi-elastic neutron scattering (QENS) measurements. Experiment and simulation give evidence of the vitrification of P3HT upon blending, and the plasticization of PCBM by P3HT. Second, we reconstruct the QENS signal based on the independent simulations of the three phases constituting the complex microstructure of such blends. Finally, we found that P3HT wrap itself around PCBM in the amorphous mixture of P3HT and PCBM; this molecular interaction between P3HT and PCBM is likely to be responsible for the observed frustration of P3HT.
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Aug 2017
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I07-Surface & interface diffraction
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Rajeev
Dattani
,
James H.
Bannock
,
Zhuping
Fei
,
Roderick
Mackenzie
,
Anne
Guilbert
,
Michelle
Vezie
,
Jenny
Nelson
,
John C.
De Mello
,
Martin
Heeney
,
Joao
Cabral
,
Alisyn
Nedoma
Diamond Proposal Number(s):
[8339]
Abstract: Block copolymers have the potential to self-assemble into thermodynamically stable nanostructures that
are desirable for plastic electronic materials with prolonged lifetimes. Fulfillment of this potential requires
the simultaneous optimisation of the spatial organisation and phase behaviour of heterogeneous thin
films at the nanoscale. We demonstrate the controlled assembly of an all-conjugated diblock copolymer
blended with fullerene. The crystallinity, nanophase separated morphology, and microscopic features are
characterised for blends of poly(3-hexylthiophene-block-3-(2-ethylhexyl) thiophene) (P3HT-b-P3EHT)
and phenyl-C61-butyric acid methyl ester (PCBM), with PCBM fractions varying from 065 wt%. We find
that PCBM induces the P3HT block to crystallise, causing nanophase separation of the block copolymer.
Resulting nanostructures range from ordered (lamellae) to disordered, depending on the amount of
PCBM. We identify the key design parameters and propose a general mechanism for controlling thin film
structure and crystallinity during the processing of semicrystalline block copolymers.
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Jul 2014
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I07-Surface & interface diffraction
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Abstract: We use grazing-incidence wide-angle X-ray scattering (GIWAXS) and molecular modeling to understand the difference in crystallization of several cyclopentadithiophene–benzothiadiazole polymer derivatives. We observe using GIWAXS that when the carbon bridging atom is substituted by a silicon atom, the π–π stacking distance is decreased while the lamellar stacking distance is increased. Using molecular modeling, we calculate the potential energy surfaces of an ordered array of oligomers as a function of π–π stacking and lamellar stacking distances and find two local minima for both the carbon and silicon analogues. This finding is consistent with the GIWAXS observations. We suggest that it may be possible to crystallize the carbon and silicon versions in the same crystal structure by varying the processing conditions. We derive new potential parameters from quantum chemical calculations for side chains motions and implement those within a new force field for molecular dynamics. We find that the side chains are more flexible in the case of the silicon bridging atom. We propose that the flexibility enhancement may influence both thermodynamics and kinetics of crystallization and may result in crystallization of the polymer in the first or the second energetically favored crystal structures. This interpretation is supported by the finding of only one minimum in potential energy for longer, less bulky, and, thus, more flexible side chains for the carbon analogue.
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Dec 2013
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I07-Surface & interface diffraction
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Anne
Guilbert
,
Luke X.
Reynolds
,
Annalisa
Bruno
,
Andrew
Maclachlan
,
Simon P.
King
,
Mark A.
Faist
,
Ellis
Pires
,
J. Emyr
Macdonald
,
Natalie
Stingelin
,
Saif A.
Haque
,
Jenny
Nelson
Diamond Proposal Number(s):
[6319]
Abstract: The bis and tris adducts of
[6,6]phenyl-C 61 -butyric acid methyl ester (PCBM)
offer lower reduction potentials than PCBM and
are therefore expected to offer larger open-circuit voltages and more efficient energy conversion
when blended with conjugated polymers in photovoltaic devices in place of PCBM. However, poor
photovoltaic device performances are commonly observed when PCBM is replaced with higher-
adduct fullerenes. In this work, we use transmission electron microscopy (TEM), steady-state and
ultrafast time-resolved photoluminescence spectroscopy (PL), and differential scanning calorimetry
(DSC) to probe the microstructural properties of blend films of poly(3-hexylthiophene-2,5-diyl)
(P3HT) with the bis and tris adducts of PCBM. TEM and PL indicate that, in as-spun blend films,
fullerenes become less soluble in P3HT as the number of adducts increases. PL indicates that upon
annealing crystallization leads to phase separation in P3HT:PCBM samples only. DSC studies indicate
that the interactions between P3HT and the fullerene become weaker with higher-adduct fullerenes
and that all systems exhibit eutectic phase behavior with a eutectic composition being shifted to
higher molar fullerene content for higher-adduct fullerenes. We propose two different mechanisms
of microstructure development for PCBM and higher-adduct fullerenes. P3HT:PCBM blends, phase
segregation is the result of crystallization of either one or both components and is facilitated by
thermal treatments. In contrast, for blends containing higher adducts, the phase separation is due to
a partial demixing of the amorphous phases. We rationalize the lower photocurrent generation by
the higher-adduct fullerene blends in terms of film microstructure.
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May 2012
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