Results
- Showing results for:
- Reset all filters
Search results
-
Journal articleDaboczi M, Al Lawati N, Stewart K, et al., 2026, , EES Solar
Integrating organic photovoltaics into anodes (IPV-anodes) represents a promising way to exploit the excellent optoelectronic properties of organic polymer: non-fullerene bulk-heterojunctions (BHJ) for solar-to-fuel applications. However, the high voltage losses, poor photochemical stability and high synthetic complexity of the most commonly used polymer: non-fullerene combinations have limited their full potential. Here, we address these limitations by introducing a BHJ comprising the low-synthetic-complexity polymer PTQ10 and the near-infrared absorbing acceptor L8-BO. By integrating this new BHJ with a graphite sheet functionalised with a NiFeOOH catalyst, we achieve a low onset potential of +0.64 VRHE, a photocurrent density of 21 mA cm-2 at +1.23 VRHE and a t 80 operational stability of 22 h under full AM1.5 G illumination (i.e., without using any UV filter) for water oxidation. These values represent a 40 mV increase in photovoltage and a sevenfold improvement in operational stability (t 80 extended from 3 h to 22 h) compared to reference IPV-anodes based on the ternary D18:PM6:L8-BO photoactive blend. Spectroscopic analyses reveal that these improvements stem from the reduced non-radiative voltage losses (from 0.24 V to 0.19 V) and superior photochemical and morphological stability of the PTQ10:L8-BO blend compared to the reference blend. Building on these advances, we demonstrate monolithic tandem IPV-anodes integrating PTQ10:IDIC and PTQ10:L8-BO organic blends to achieve a solar-to-hydrogen efficiency of 6.2%, offering critical insights for boosting the stability and efficiency of integrated solar-to-hydrogen systems working without any external bias.
-
Journal articleHenderson C, Marques AS, Bicalho IS, et al., 2026, , ACS applied materials & interfaces, ISSN: 1944-8244
As lab-scale perovskite solar cells (PSCs) approach their efficiency limits, reproducing this performance in large-area, manufacturable devices remains challenging. Here, we show that printing interlayers of metal oxide nanoparticles, specifically Al2O3 and SnO2, can systematically control the morphology and interfacial energetics of solution-processed PC61BM electron transport layers (ETLs) in flexible roll-to-roll printed PSCs. These nanoparticle interlayers enhance ETL uniformity, reduce pinholes, and increase shunt resistance, improving power conversion efficiencies (PCEs) and reducing device failure rates by 50%. Through a combination of systematic device characterization, morphological, spectroscopic and energetic analysis, coupled with drift-diffusion simulations, the distinct roles of insulating (Al2O3) and semiconducting (SnO2) nanoparticle interlayers in mediating carrier extraction and recombination are elucidated. Al2O3 suppresses interfacial recombination and improves device reproducibility, albeit with some penalty in short-circuit current, whereas SnO2 enhances electronic coupling and charge extraction, delivering a champion PCE of 11.0% (active area: 0.5 cm2). Incorporating SnO2 interlayers into larger-area modules (active area: 7.2 cm2) further demonstrates the robustness of this strategy under manufacturing-relevant conditions. Together, these results provide an important framework for nanoparticle-mediated interface engineering and establish a simple, effective, and scalable route to improving both performance and yield in printed large-area PSCs.
-
Journal articleLuke J, Chen S, He Q, et al., 2026, , Ees Solar, Vol: 2, Pages: 235-245
Despite the excellent progress in organic photovoltaic (OPV) efficiencies, they still suffer from poor operational stability. This is especially true in ambient conditions, with degradation often driven by intrinsic material instabilities. Fluorination of the constituent organic semiconductors, which deepens frontier orbitals and improves organic semiconducting packing, is often utilised to improve photostability. Here, fluorinated analogues of the high-performance workhorse polymer PBDB-T are synthesised and their photostability characterised. Device stability, with both Y6 and IT-4F, is found to be critically dependent on the intrinsic polymer photostability, with fluorination of the benzodithiophene (BDT) being particularly ruinous for stability. The co-monomer carbonyl groups in these unstable BDT-fluorinated analogues are found to be highly unstable towards illumination. This instability arises from a disruption of non-covalent interactions along the polymer backbone, where the fluorine on BDT interferes with intramolecular S–O interactions between the thiophene and benzodithiophene-dione (BDD) carbonyl. This leads to increased backbone disorder and a more vulnerable carbonyl environment. These results challenge the conventional belief that fluorination universally improves OPV stability and underscore the crucial role of non-covalent interactions in governing material stability.
-
Journal articleStewart K, Tan E, Kim J, et al., 2026, , Advanced Electronic Materials
Understanding polaron formation in conjugated polymers is critical for advancing solid-state organic electronics. Here, we investigate diketopyrrolopyrrole (DPP)-based polymers with tailored side chains to elucidate the impact of glycolation on charge transport and polaron formation. We demonstrate that glycol side chains enhance p-type character and charge carrier density, while backbone elongation improves planarity and mobility. Electrochemical doping using a semicrystalline solid-state ionic liquid (SSIL) can increase conductivity by four orders of magnitude. In situ field-dependent Raman spectroscopy probes polaron formation, showing increased π-electron redistribution in glycolated DPP. Polaron formation of the DPPT-T conjugated backbone shows a more localised polaron with structural changes to the thiophene donor unit. Backbone elongation results in greater polaron delocalisation with lower reorganisation energy. Finally, ion-gel gated organic synaptic transistors (IGOSTs) demonstrate significant performance gains for glycolated polymers with gDPPT-T and gDPPT-TVT exhibiting strong excitatory post-synaptic currents. The more facile polaron formation pathway for gDPPT-TVT offers a significant advantage in the dynamics of ion migration and retention. This work provides molecular-level insight into the incorporation of glycol side chains to high-performance conjugated polymers for solid-state applications.
-
Journal articlePark SY, Labanti C, Fang F, et al., 2025, , ADVANCED OPTICAL MATERIALS, ISSN: 2195-1071
-
Journal articleSu R, Chai J, Pei Y, et al., 2025, , ADVANCED MATERIALS, ISSN: 0935-9648
-
Journal articleLabanti C, Sun Y, Luke J, et al., 2025, , ADVANCED OPTICAL MATERIALS, Vol: 13, ISSN: 2195-1071
- Cite
- Citations: 2
-
Journal articleForrester C, Augurio A, Henderson C, et al., 2025, , ADVANCED FUNCTIONAL MATERIALS, ISSN: 1616-301X
-
Journal articleLukas T, Seo S, Holzhey P, et al., 2025, , ACS ENERGY LETTERS, Vol: 10, Pages: 2736-2742, ISSN: 2380-8195
- Cite
- Citations: 3
-
Journal articleLambeva NT, Limbu S, Kim J-S, et al., 2025, , JOURNAL OF POLYMER SCIENCE, Vol: 63, Pages: 2113-2121, ISSN: 2642-4150
-
Journal articleDaboczi M, Eisner F, Luke J, et al., 2025, , Nature Energy, Vol: 10, Pages: 581-591, ISSN: 2058-7546
Polymer donors and non-fullerene acceptors have played an important role as photoactive materials in the development of high-efficiency organic solar cells and have immense potential in devices for direct solar hydrogen generation. However, their use in direct solar water-splitting devices has been limited by their instability in aqueous environment and recombination losses at the interface with catalysts. Here we report anodes containing PM6:D18:L8-BO photoactive layers reaching high solar water oxidation photocurrent density over 25 mA cm−2 at +1.23 V versus reversible hydrogen electrode and days-long operational stability. This was achieved by integrating the organic photoactive layer with a graphite sheet functionalized with earth-abundant NiFeOOH water oxidation catalyst, which provides both water resistance and electrical connection between the catalyst and the photoactive layer without any losses. Using monolithic tandem anodes containing organic PM6:D18:L8-BO and PTQ10:GS-ISO photoactive layers, we achieve a solar-to-hydrogen efficiency of 5%. These results pave the way towards high-efficiency, stable and unassisted solar hydrogen generation by low-cost organic photoactive materials.
-
Journal articleFu Y, Xu L, Li Y, et al., 2024, , ENERGY & ENVIRONMENTAL SCIENCE, Vol: 17, Pages: 8893-8903, ISSN: 1754-5692
-
Journal articleZhang L, Lee S, Park SY, et al., 2024, , ADVANCED SCIENCE, Vol: 11
-
Journal articleAlsufyani M, Moss B, Tait CE, et al., 2024, , ADVANCED MATERIALS, Vol: 36, ISSN: 0935-9648
-
Journal articleYang EJ, Luke J, Fu Y, et al., 2024, , ADVANCED FUNCTIONAL MATERIALS, Vol: 34, ISSN: 1616-301X
-
Journal articleBlakesley JC, Bonilla RS, Freitag M, et al., 2024, , JPhys Energy, Vol: 6, ISSN: 2515-7655
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 fulfill 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 PVs 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.
-
Journal articlePagano K, Kim JG, Luke J, et al., 2024, , Nature Communications, Vol: 15, ISSN: 2041-1723
Glycol sidechains are often used to enhance the performance of organic photoconversion and electrochemical devices. Herein, we study their effects on electronic states and electronic properties. We find that polymer glycolation not only induces more disordered packing, but also results in a higher reorganisation energy due to more localised π-electron density. Transient absorption spectroscopy and femtosecond stimulated Raman spectroscopy are utilised to monitor the structural relaxation dynamics coupled to the excited state formation upon photoexcitation. Singlet excitons are initially formed, followed by polaron pair formation. The associated structural relaxation slows down in glycolated polymers (5 ps vs. 1.25 ps for alkylated), consistent with larger reorganisation energy. This slower vibrational relaxation is found to drive ultrafast formation of the polaron pair state (5 ps vs. 10 ps for alkylated). These results provide key experimental evidence demonstrating the impact of molecular structure on electronic state formation driven by strong vibrational coupling.
-
Journal articleRana A, Park SY, Labanti C, et al., 2024, , Nature Communications, Vol: 15, ISSN: 2041-1723
In this study, high-performance organic photodetectors are presented which utilize a pristine chlorinated subphthalocyanine photoactive layer. Optical and optoelectronic analyses indicate that the device photocurrent is primarily generated through direct charge generation within the chlorinated subphthalocyanine layer, rather than exciton separation at layer interfaces. Molecular modelling suggests that this direct charge generation is facilitated by chlorinated subphthalocyanine high octupole moment (−80 DÅ2), which generates a 200 meV shift in molecular energetics. Increasing the thickness of chlorinated subphthalocyanine leads to faster response time, correlated with a decrease in trap density. Notably, photodetectors with a 50 nm thick chlorinated subphthalocyanine photoactive layer exhibit detectivities approaching 1013 Jones, with a dark current below 10−7 A cm−2 up to −5 V. Based on these findings, we conclude that high octupole moment molecular semiconductors are promising materials for high-performance organic photodetectors employing single-component photoactive layer.
-
Journal articleDi Mari G, Yao C, LAN T, et al., 2024, , ChemSusChem: chemistry and sustainability, energy and materials, ISSN: 1864-5631
The growing demand for efficient and high-performance energy storage systems is driving the exploration of novel materials and composites. Traditional electrode materials often face limitations in terms of energy and power densities. This paper demonstrates novel spray-coated cathode electrode system composed of Ti3C2Tx MXene and zinc hydroxy fluoride/zinc oxide (ZnOHF/ZnO) nanostars (NSs) for energy storage applications in a neutral pH electrolyte. Optimized Ti3C2Tx-NSs electrodes exhibited superior specific capacitance, achieving 236 F g−1 at 5 mV s−1 in cyclic voltammetry (CV) and 139 F g−1 at 5 mV s−1 in galvanostatic charge-discharge (GCD) measurements, which is superior to bare Ti3C2Tx (115 F g−1 at 0.5 A g−1) and bare NSs (108 F g−1 at 0.5 F g−1) electrodes, used as reference. Additionally, an asymmetric Ti3C2Tx||Ti3C2Tx-NSs supercapacitor device achieved a specific capacitance of 147 F g−1 at 0.5 A g−1, an energy density Ed ~ 46 W h kg−1 at a power density Pd ~ 875 W kg−1, and the highest Pd ~ 16650 W kg−1 at Ed ~ 14 W h kg−1. These findings demonstrate that ZnO NSs combined with delaminated Ti3C2Tx MXene, hold a significant promise for efficient energy storage applications, leveraging the synergy between double-layer capacitance and pseudocapacitive effects.
-
Journal articleStewart K, Pagano K, Tan E, et al., 2024, , Advanced Materials, Vol: 36, ISSN: 0935-9648
Polarons exist when charges are injected into organic semiconductors due to their strong coupling with the lattice phonons, significantly affecting electronic charge-transport properties. Understanding the formation and (de)localization of polarons is therefore critical for further developing organic semiconductors as a future electronics platform. However, there are very few studies reported in this area. In particular, there is no direct in situ monitoring of polaron formation and identification of its dependence on molecular structure and impact on electrical properties, limiting further advancement in organic electronics. Herein, how a minor modification of side-chain density in thiophene-based conjugated polymers affects the polaron formation via electrochemical doping, changing the polymers’ electrical response to the surrounding dielectric environment for gas sensing, is demonstrated. It is found that the reduction in side-chain density results in a multistep polaron formation, leading to an initial formation of localized polarons in thiophene units without side chains. Reduced side-chain density also allows the formation of a high density of polarons with fewer polymer structural changes. More numerous but more localized polarons generate a stronger analyte response but without the selectivity between polar and non-polar solvents, which is different from the more delocalized polarons that show clear selectivity. The results provide important molecular understanding and design rules for the polaron formation and its impact on electrical properties.
-
Journal articleWu D-T, Zhu W-X, Dong Y, et al., 2024, , small methods, ISSN: 2366-9608
Tin-lead (Sn-Pb) perovskite solar cells (PSCs) have gained interest as candidates for the bottom cell of all-perovskite tandem solar cells due to their broad absorption of the solar spectrum. A notable challenge arises from the prevalent use of the hole transport layer, PEDOT:PSS, known for its inherently high doping level. This high doping level can lead to interfacial recombination, imposing a significant limitation on efficiency. Herein, NaOH is used to dedope PEDOT:PSS, with the aim of enhancing the efficiency of Sn-Pb PSCs. Secondary ion mass spectrometer profiles indicate that sodium ions diffuse into the perovskite layer, improving its crystallinity and enlarging its grains. Comprehensive evaluations, including photoluminescence and nanosecond transient absorption spectroscopy, confirm that dedoping significantly reduces interfacial recombination, resulting in an open-circuit voltage as high as 0.90 V. Additionally, dedoping PEDOT:PSS leads to increased shunt resistance and high fill factor up to 0.81. As a result of these improvements, the power conversion efficiency is enhanced from 19.7% to 22.6%. Utilizing NaOH to dedope PEDOT:PSS also transitions its nature from acidic to basic, enhancing stability and exhibiting less than a 7% power conversion efficiency loss after 1176 h of storage in N2 atmosphere.
-
Journal articleClarke AJ, Yang EJ, Thomas SK, et al., 2024, , ADVANCED ENERGY AND SUSTAINABILITY RESEARCH, ISSN: 2699-9412
-
Journal articlePark SY, Labanti C, Pacalaj RA, et al., 2023, , Advanced Materials, Vol: 35, ISSN: 0935-9648
A bulk-heterojunction (BHJ) blend is commonly used as the photoactive layer in organic photodetectors (OPDs) to utilize the donor (D)/acceptor (A) interfacial energetic offset for exciton dissociation. However, this strategy often complicates optimization procedures, raising serious concerns over device processability, reproducibility, and stability. Herein, highly efficient OPDs fabricated with single-component organic semiconductors are demonstrated via solution-processing. The non-fullerene acceptors (NFAs) with strong intrinsic D/A character are used as the photoactive layer, where the emissive intermolecular charge transfer excitonic (CTE) states are formed within <1 ps, and efficient photocurrent generation is achieved via strong quenching of these CTE states by reverse bias. Y6 and IT-4F-based OPDs show excellent OPD performances, low dark current density (≈10-9 A cm-2 ), high responsivity (≥0.15 A W-1 ), high specific detectivity (>1012 Jones), and fast photo-response time (<10 µs), comparable to the state-of-the-art BHJ OPDs. Together with strong CTE state quenching by electric field, these excellent OPD performances are also attributed to the high quadrupole moments of NFA molecules, which can lead to large interfacial energetic offset for efficient CTE dissociation. This work opens a new way to realize efficient OPDs using single-component systems via solution-processing and provides important molecular design rules.
-
Journal articleYan H, Cong S, Daboczi M, et al., 2023, , Advanced Optical Materials, Vol: 11, ISSN: 2195-1071
For an ideal electron interlayer, both electron injection and hole-blocking properties are important to achieve better polymer light-emitting devices (PLEDs) performance. Conjugated polyelectrolytes (CPEs) are applied widely in PLEDs to enhance charge injection. Understanding the role of backbone structures and energetic matching between the CPEs and emitters can benefit charge injection and balance. Herein, a postpolymerization approach to introduce varying amounts of alkyl sulfonate groups onto the backbone of a copolymer of 5-fluoro-2,1,3-benzothiadiazole and 9,9′-dioctylfluorene is utilized. This study finds that device performance is dependent on the percentage of sulfonate groups incorporated, with the optimal copolymer (CPE-50%) maintaining efficient ohmic electron injection and gaining enhanced hole-blocking properties, thereby achieving the most balanced hole/electron current. Therefore, the PLED with CPE-50% interlayer exhibits the highest efficiency (20.3 cd A−1, 20.2 lm W−1) and the fastest response time (4.3 µs), which is the highest efficiency among conventional thin (70 nm) F8BT PLEDs with CPEs. These results highlight the importance of balanced charge carrier density in CPEs and highlight that postpolymerization modification is a useful method for fine-tuning ionic content.
-
Journal articleHenderson C, Luke J, Bicalho I, et al., 2023, , Energy and Environmental Science, Vol: 16, Pages: 5891-5903, ISSN: 1754-5692
Light soaking (LS) is a well-known but poorly understood phenomenon in perovskite solar cells (PSCs) which significantly affects device efficiency and stability. LS is greatly reduced in large-area inverted PSCs when a PC61BM electron transport layer (ETL) is replaced with C60, where the ETL is commonly in contact with a thin bathocuproine (BCP) interlayer. Herein, we identify the key molecular origins of this LS effect using a combination of surface photovoltage, ambient photoemission spectroscopy, Raman spectroscopy, integrated with density functional theory simulations. We find that BCP forms a photoinduced charge-transfer (CT) complex with both C60 and PC61BM. The C60/BCP complex accelerates C60 dimer formation, leading to a favourable cascading energetic landscape for electron extraction and reduced recombination loss. In contrast, the PC61BM/BCP complex suppresses PC61BM dimer formation, meaning that PC61BM dimerisation is not the cause of LS. Instead, it is the slow light-induced formation of the PC61BM/BCP CT complex itself, and the new energetic transport levels associated with it, which cause the much slower and stronger LS effect of PC61BM based PSCs. These findings provide key understanding of photoinduced ETL/BCP interactions and their impact on the LS effect in PSCs.
-
Journal articleYang M, Cui J, Daboczi M, et al., 2023, , ADVANCED MATERIALS INTERFACES, Vol: 10, ISSN: 2196-7350
-
Journal articleLuke J, Yang EJ, Labanti C, et al., 2023, , Nature Reviews Materials, ISSN: 2058-8437
Organic photovoltaics (OPVs) have rapidly improved in efficiency, with single-junction cells now exceeding 18% efficiency. These improvements have been driven by the adoption of new non-fullerene acceptors and the fine tuning of their molecular structures. Although OPVs are highly efficient, they often show extremely poor operational stability, primarily owing to the complex interplay between the morphological instability of the blended bulk heterojunction photoactive layers and the intrinsically poor photostability of the organic semiconductor materials themselves. To realize commercialization, it is vital to understand the degradation mechanisms of these organic materials to improve their stability. Efficiency increases have, in part, been driven by the rational molecular design of materials. In this Perspective, we examine how a similar bottom-up molecular design can be applied to OPV stability. Specifically, we highlight key molecular design parameters and demonstrate how each parameter impacts different degradation pathways. Looking forward, we propose that fundamental understanding of the molecular origin of OPV stability is a key research theme for next-generation OPVs. Additionally, we discuss the tools required, across length scales, to implement these design rules, particularly the use of in situ Raman spectroscopy as a critical bridge linking the molecular scale to the nanoscale and beyond.
-
Journal articleWang Y, Daboczi M, Zhang M, et al., 2023, , MATERIALS HORIZONS, ISSN: 2051-6347
-
Journal articleHart LJF, Gruene J, Liu W, et al., 2023, , ADVANCED ENERGY MATERIALS, Vol: 13, ISSN: 1614-6832
- Cite
- Citations: 16
-
Journal articleJiang Z, Du T, Lin C, et al., 2023, , Advanced Materials Interfaces, Vol: 10, ISSN: 2196-7350
With the rapid development of perovskite solar cells, reducing losses in open-circuit voltage (Voc) is a key issue in efforts to further improve device performance. Here it is focused on investigating the correlation between the highest occupied molecular orbital (HOMO) of device hole transport layers (HTLs) and device Voc. To achieve this, structurally similar HTL materials with comparable optical band gaps and doping levels, but distinctly different HOMO levels are employed. Using light-intensity dependent Voc and photoluminescence measurements significant differences in the behavior of devices employing the two HTLs are highlighted. Light-induced increase of quasi-Fermi level splitting (ΔEF) in the perovskite layer results in interfacial quasi-Fermi level bending required to align with the HOMO level of the HTL, resulting in the Voc measured at the contacts being smaller than the ΔEF in the perovskite. It is concluded that minimizing the energetic offset between HTLs and the perovskite active layer is of great importance to reduce non-radiative recombination losses in perovskite solar cells with high Voc values that approach the radiative limit.
This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.
