1. |
- Campbell, PJ, et al.
(författare)
-
Pan-cancer analysis of whole genomes
- 2020
-
Ingår i: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 578:7793, s. 82-
-
Tidskriftsartikel (refereegranskat)abstract
- Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale1–3. Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4–5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter4; identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation5,6; analyses timings and patterns of tumour evolution7; describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity8,9; and evaluates a range of more-specialized features of cancer genomes8,10–18.
|
|
2. |
|
|
3. |
- Luo, Yifei, et al.
(författare)
-
Technology Roadmap for Flexible Sensors
- 2023
-
Ingår i: ACS Nano. - : American Chemical Society. - 1936-0851 .- 1936-086X. ; 17:6, s. 5211-5295
-
Forskningsöversikt (refereegranskat)abstract
- Humans rely increasingly on sensors to address grand challenges and to improve quality of life in the era of digitalization and big data. For ubiquitous sensing, flexible sensors are developed to overcome the limitations of conventional rigid counterparts. Despite rapid advancement in bench-side research over the last decade, the market adoption of flexible sensors remains limited. To ease and to expedite their deployment, here, we identify bottlenecks hindering the maturation of flexible sensors and propose promising solutions. We first analyze challenges in achieving satisfactory sensing performance for real-world applications and then summarize issues in compatible sensor-biology interfaces, followed by brief discussions on powering and connecting sensor networks. Issues en route to commercialization and for sustainable growth of the sector are also analyzed, highlighting environmental concerns and emphasizing nontechnical issues such as business, regulatory, and ethical considerations. Additionally, we look at future intelligent flexible sensors. In proposing a comprehensive roadmap, we hope to steer research efforts towards common goals and to guide coordinated development strategies from disparate communities. Through such collaborative efforts, scientific breakthroughs can be made sooner and capitalized for the betterment of humanity.
|
|
4. |
- Zhang, Tiankai, et al.
(författare)
-
Ion-modulated radical doping of spiro-OMeTAD for more efficient and stable perovskite solar cells
- 2022
-
Ingår i: Science. - : AMER ASSOC ADVANCEMENT SCIENCE. - 0036-8075 .- 1095-9203. ; 377:6605, s. 495-501
-
Tidskriftsartikel (refereegranskat)abstract
- Record power conversion efficiencies (PCEs) of perovskite solar cells (PSCs) have been obtained with the organic hole transporter 2,2,7,7-tetrakis(N,N-di-p-methoxyphenyl-amine)9,9-spirobifluorene (spiro-OMeTAD). Conventional doping of spiro-OMeTAD with hygroscopic lithium salts and volatile 4-tert-butylpyridine is a time-consuming process and also leads to poor device stability. We developed a new doping strategy for spiro-OMeTAD that avoids post-oxidation by using stable organic radicals as the dopant and ionic salts as the doping modulator (referred to as ion-modulated radical doping). We achieved PCEs of >25% and much-improved device stability under harsh conditions. The radicals provide hole polarons that instantly increase the conductivity and work function (WF), and ionic salts further modulate the WF by affecting the energetics of the hole polarons. This organic semiconductor doping strategy, which decouples conductivity and WF tunability, could inspire further optimization in other optoelectronic devices.
|
|
5. |
- Bai, Yang, et al.
(författare)
-
Geometry design of tethered small-molecule acceptor enables highly stable and efficient polymer solar cells
- 2023
-
Ingår i: Nature Communications. - : NATURE PORTFOLIO. - 2041-1723. ; 14:1
-
Tidskriftsartikel (refereegranskat)abstract
- With the power conversion efficiency of binary polymer solar cells dramatically improved, the thermal stability of the small-molecule acceptors raised the main concerns on the device operating stability. Here, to address this issue, thiophene-dicarboxylate spacer tethered small-molecule acceptors are designed, and their molecular geometries are further regulated via the thiophene-core isomerism engineering, affording dimeric TDY-alpha with a 2, 5-substitution and TDY-beta with 3, 4-substitution on the core. It shows that TDY-alpha processes a higher glass transition temperature, better crystallinity relative to its individual small-molecule acceptor segment and isomeric counterpart of TDY-beta, and amore stablemorphology with the polymer donor. As a result, the TDY-alpha based device delivers a higher device efficiency of 18.1%, and most important, achieves an extrapolated lifetime of about 35000 hours that retaining 80% of their initial efficiency. Our result suggests that with proper geometry design, the tethered small-molecule acceptors can achieve both high device efficiency and operating stability.
|
|
6. |
- Cao, Qi, et al.
(författare)
-
N-Type Conductive Small Molecule Assisted 23.5% Efficient Inverted Perovskite Solar Cells
- 2022
-
Ingår i: Advanced Energy Materials. - : John Wiley & Sons. - 1614-6832 .- 1614-6840. ; 12:34
-
Tidskriftsartikel (refereegranskat)abstract
- Because of the compatibility with tandem devices and the ability to be manufactured at low temperatures, inverted perovskite solar cells have generated far-ranging interest for potential commercial applications. However, their efficiency remains inadequate owing to various traps in the perovskite film and the restricted hole blocking ability of the electron transport layer. Thus, in this work, a wide-bandgap n-type semiconductor, 4,6-bis(3,5-di(pyridin-4-yl)phenyl)-2-phenylpyrimidine (B4PyPPM), to modify a perovskite film via an anti-solvent method is introduced. The nitrogen sites of pyrimidine and pyridine rings in B4PyPPM exhibit strong interactions with the undercoordinated lead ions in the perovskite material. These interactions can reduce the trap state densities and inhibit nonradiative recombination of the perovskite bulk. Moreover, B4PyPPM can partially aggregate on the perovskite surface, leading to an improvement in the hole-blocking ability at its interface. This modification can also increase the built-in potential and upshift the Fermi level of the modified perovskite film, promoting electron extraction to the electron transport layer. The champion device achieves a high efficiency of 23.51%. Meantime, the sealed device retains approximate to 80% of its initial performance under a maximum power point tracking for nearly 2400 h, demonstrating an excellent operational stability.
|
|
7. |
- Wang, Shuangjie, et al.
(författare)
-
Critical Role of Removing Impurities in Nickel Oxide on High-Efficiency and Long-Term Stability of Inverted Perovskite Solar Cells
- 2022
-
Ingår i: Angewandte Chemie International Edition. - : John Wiley & Sons. - 1433-7851 .- 1521-3773. ; 61:18
-
Tidskriftsartikel (refereegranskat)abstract
- The performance enhancement of inverted perovskite solar cells applying nickel oxide (NiOx) as the hole transport layer (HTL) has been limited by impurity ions (such as nitrate ions). Herein, we have proposed a strategy to obtain high-quality NiOx nanoparticles via an ionic liquid-assisted synthesis method (NiOx-IL). Experimental and theoretical results illustrate that the cation of the ionic liquid can inhibit the adsorption of impurity ions on nickel hydroxide through a strong hydrogen bond and low adsorption energy, thereby obtaining NiOx-IL HTL with high conductivity and strong hole-extraction ability. Importantly, the removal of impurity ions can effectively suppress the redox reaction between the NiOx film and the perovskite film, thus slowing down the deterioration of device performance. Consequently, the modified inverted device shows a striking efficiency exceeding 22.62 %, and superior stability maintaining 92 % efficiency at a maximum power point tracking under one sun illumination for 1000 h.
|
|
8. |
- Wang, Tong, et al.
(författare)
-
Deep defect passivation and shallow vacancy repair via an ionic silicone polymer toward highly stable inverted perovskite solar cells
- 2022
-
Ingår i: Energy & Environmental Science. - : Royal Society of Chemistry. - 1754-5692 .- 1754-5706. ; 15:10, s. 4414-4424
-
Tidskriftsartikel (refereegranskat)abstract
- Additive engineering is an effective strategy for defect passivation and performance improvement of perovskite solar cells (PSCs). However, few additives have achieved outstanding stability with high efficiency by simultaneously passivating deep and shallow defects. Herein, we design a novel ionic silicone polymer (PECL) with multi-active sites as an additive to modify inverted PSCs. The C-O groups in the PECL polymer can chelate with undercoordinated Pb2+ and Pb clusters to passivate deep defects; and the ionic groups in the PECL polymer can generate electrostatic interaction with both positively and negatively charged vacancies, which help to repair shallow defects. Moreover, we quantitatively reveal the effect of deep and shallow defects on the efficiency and stability of PSCs separately, by establishing the correlation between additives with different functional groups and the performance of devices. Consequently, the power conversion efficiency of the PECL-modified inverted PSC increases from 20.02% to 23.11%. More importantly, the encapsulated PSCs maintain 95% of their initial steady-state power output after 1500 hours under AM 1.5 illumination at the maximum power point at 45 degrees C. Therefore, we provide a universal guideline of polymer structure design for defect healing in stabilizing PSCs with high efficiency.
|
|
9. |
- Yang, Jiabao, et al.
(författare)
-
Inhibiting metal-inward diffusion-induced degradation through strong chemical coordination toward stable and efficient inverted perovskite solar cells
- 2022
-
Ingår i: Energy & Environmental Science. - : Royal Society of Chemistry. - 1754-5692 .- 1754-5706. ; 15:5, s. 2154-2163
-
Tidskriftsartikel (refereegranskat)abstract
- The inward diffusion of metal electrodes is one of the main reasons for the deterioration of the long-term device stability of perovskite solar cells (PSCs). Thus, herein, we adopt a simple additive engineering strategy to modify the barrier material bathocuproine (BCP) with 1,3,5-triazine-2,4,6-trithiol trisodium salt (TTTS). Different from the traditional physical blocking strategies, TTTS could prevent the metal electrodes (e.g., gold, silver, and copper) from diffusing inward through the strong chemical coordination between TTTS and the metal electrode. The TTTS additive also improved the conductivity and band structure of BCP, thus enhancing the ability of BCP to extract electrons from the perovskite layer to the electrode. Consequently, the inverted device modified with TTTS exhibited a high efficiency of 22.59%, which is among the highest efficiencies reported to date for inverted PSCs. More importantly, it showed excellent operational, ambient, and thermal stability. The target device maintained its initial efficiency with no loss under continuous one-sun illumination at maximum power point tracking after 1000 h (the champion device), 91% in air (50% +/- 5% RH) for 5000 h, and 93% after heating at 85 degrees C for 1500 h (average efficiency from ten devices).
|
|
10. |
- Yang, Jiabao, et al.
(författare)
-
Overcome Low Intrinsic Conductivity of NiOx Through Triazinyl Modification for Highly Efficient and Stable Inverted Perovskite Solar Cells
- 2022
-
Ingår i: Solar RRL. - : John Wiley & Sons. - 2367-198X. ; 6:9
-
Tidskriftsartikel (refereegranskat)abstract
- Nickel oxide (NiOx) is a promising hole transport material in inverted organic-inorganic metal halide perovskite solar cells. However, its low intrinsic conductivity hinders its further improvement in device performance. Here, we employ a trimercapto-s-triazine trisodium salt (TTTS) as a chelating agent of Ni2+ in the NiOx layer to improve its conductivity. Due to the electron-deficient triazine ring, the TTTS complexes with Ni2+ in NiOx via a strong Ni2+-N coordination bond and increases the ratio of Ni3+:Ni2+. The increased Ni3+ concentration adjusts the band structure of NiOx, thus enhancing hole density and mobility, eventually improving the intrinsic conductivity of NiOx. As a result, the device with TTTS modification displays a champion power conversion efficiency (PCE) of 22.81%. The encapsulated device based on a modified-NiOx layer maintains 94% of its initial power output at the maximum power point and continuous one-sun illumination for 1000 h at 45 degrees C. In addition, the unencapsulated target devices also maintain 92% at 60 +/- 5% relative humidity and 25 degrees C in the air for 5000 h; and 91% at 85 degrees C in a nitrogen atmosphere for 1000 h. The research provides an effective strategy to enhance PCE and stability of inverted PSCs via modifying NiOx films with triazine molecule.
|
|
11. |
|
|
12. |
- Bravo, L, et al.
(författare)
-
- 2021
-
swepub:Mat__t
|
|
13. |
- Tabiri, S, et al.
(författare)
-
- 2021
-
swepub:Mat__t
|
|
14. |
- Alharbi, Essa A., et al.
(författare)
-
Formation of High-Performance Multi-Cation Halide Perovskites Photovoltaics by delta-CsPbI3/delta-RbPbI3 Seed-Assisted Heterogeneous Nucleation
- 2021
-
Ingår i: Advanced Energy Materials. - : John Wiley & Sons. - 1614-6832 .- 1614-6840. ; 11:16
-
Tidskriftsartikel (refereegranskat)abstract
- The performance of perovskite solar cells is highly dependent on the fabrication method; thus, controlling the growth mechanism of perovskite crystals is a promising way towards increasing their efficiency and stability. Herein, a multi-cation halide composition of perovskite solar cells is engineered via the two-step sequential deposition method. Strikingly, it is found that adding mixtures of 1D polymorphs of orthorhombic delta-RbPbI3 and delta-CsPbI3 to the PbI2 precursor solution induces the formation of porous mesostructured hexagonal films. This porosity greatly facilitates the heterogeneous nucleation and the penetration of FA (formamidinium)/MA (methylammonium) cations within the PbI2 film. Thus, the subsequent conversion of PbI2 into the desired multication cubic alpha-structure by exposing it to a solution of formamidinium methylammonium halides is greatly enhanced. During the conversion step, the delta-CsPbI3 also is fully integrated into the 3D mixed cation perovskite lattice, which exhibits high crystallinity and superior optoelectronic properties. The champion device shows a power conversion efficiency (PCE) over 22%. Furthermore, these devices exhibit enhanced operational stability, with the best device retaining more than 90% of its initial value of PCE under 1 Sun illumination with maximum power point tracking for 400 h.
|
|
15. |
- Bogachuk, Dmitry, et al.
(författare)
-
Perovskite Solar Cells with Carbon-Based Electrodes - Quantification of Losses and Strategies to Overcome Them
- 2022
-
Ingår i: Advanced Energy Materials. - : John Wiley & Sons. - 1614-6832 .- 1614-6840. ; 12:10
-
Tidskriftsartikel (refereegranskat)abstract
- Carbon-based electrodes represent a promising approach to improve stability and up-scalability of perovskite photovoltaics. The temperature at which these contacts are processed defines the absorber grain size of the perovskite solar cell: in cells with low-temperature carbon-based electrodes (L-CPSCs), layer-by-layer deposition is possible, allowing perovskite crystals to be large (>100 nm), while in cells with high-temperature carbon-based contacts (H-CPSCs), crystals are constrained to 10-20 nm in size. To enhance the power conversion efficiency of these devices, the main loss mechanisms are identified for both systems. Measurements of charge carrier lifetime, quasi-Fermi level splitting (QFLS) and light-intensity-dependent behavior, supported by numerical simulations, clearly demonstrate that H-CPSCs strongly suffer from non-radiative losses in the perovskite absorber, primarily due to numerous grain boundaries. In contrast, large crystals of L-CPSCs provide a long carrier lifetime (1.8 mu s) and exceptionally high QFLS of 1.21 eV for an absorber bandgap of 1.6 eV. These favorable characteristics explain the remarkable open-circuit voltage of over 1.1 V in hole-selective layer-free L-CPSCs. However, the low photon absorption and poor charge transport in these cells limit their potential. Finally, effective strategies are provided to reduce non-radiative losses in H-CPSCs, transport losses in L-CPSCs, and to improve photon management in both cell types.
|
|
16. |
- Bogachuk, Dmitry, et al.
(författare)
-
Rethinking Electrochemical Deposition of Nickel Oxide for Photovoltaic Applications
- 2024
-
Ingår i: Solar RRL. - : John Wiley & Sons. - 2367-198X. ; 8:2
-
Tidskriftsartikel (refereegranskat)abstract
- A thin layer of sputtered or wet-processed nickel oxide (NiOx) is often used to fabricate perovskite solar cells (PSCs). Remarkably, NiOx can also be deposited by a recently developed electrochemical method, which is considered promising due to its short processing time, absence of high-vacuum conditions, and ease of manufacturing. Such electrochemically deposited NiOx (eleNiOx) is obtained by applying an electric bias to the front electrode of a PSC or perovskite solar module (PSM). Therefore, the electrode sheet resistance affects the current distribution through it, creating a gradient in the amount of charge provided for the electrochemical reaction. Consequently, this leads to the inhomogeneity in the formed eleNiOx, which has numerous implications on the final photovoltaic performance of PSMs. In this work, the interdependencies between the electrode sheet resistance, current distribution, eleNiOx thickness gradient, and the caused power losses of large area PSMs are discussed. By coupling the experimental findings with our numerical simulations, it is found that heterogeneity in surface potential of even small-sized modules can lead to severe differences in local eleNiOx thickness and photovoltaic performance. Therefore the potential drop across the front electrode is an inherent problem of this deposition method and potential approaches are proposed to minimize it. The synergy between several numerical simulation methods and the experimental work provides an additional critical insight into the electrochemical deposition process of nickel oxide and how important it is for the performance and stability of the large-area perovskite photovoltaic modules. It is believed that the conclusions drawn from this study are universally applicable to other electrochemically deposited layers as well.image (c) 2023 WILEY-VCH GmbH
|
|
17. |
- Campanari, Valerio, et al.
(författare)
-
Reevaluation of Photoluminescence Intensity as an Indicator of Efficiency in Perovskite Solar Cells
- 2022
-
Ingår i: Solar RRL. - : John Wiley & Sons. - 2367-198X. ; 6:8
-
Tidskriftsartikel (refereegranskat)abstract
- The photoluminescence (PL) intensity is often used as an indicator of the performance of perovskite solar cells and indeed the PL technique is often used for the characterization of these devices and their constituent materials. Herein, a systematic approach is presented to the comparison of the conversion efficiency and the PL intensity of a cell in both open-circuit (OC) and short-circuit (SC) conditions and its application to multiple heterogeneous devices. It is shown that the quenching of the PL observed in SC conditions is a good parameter to assess the device efficiency. The authors explain the dependence of the PL quenching ratio between OC and SC on the cell efficiency with a simple model that is also able to estimate the carrier extraction time of a device.
|
|
18. |
- Choi, Hyeon-Seo, et al.
(författare)
-
Oriented Crystal Growth during Perovskite Surface Reconstruction
- 2022
-
Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 14:45, s. 51149-51156
-
Tidskriftsartikel (refereegranskat)abstract
- Surface passivation has become a key strategy for an improvement in power conversion efficiency (PCE) of perovskite solar cells (PSCs) since PSCs experienced a steep increase in PCE and reached a comparably matured point. Recently, surface passivation using a mixed salt of fluorinated alkyl ammonium iodide and formamidinium bromide demon-strated a remarkable improvement in both performance and stability, which can be tuned by the length of the alkyl chain. Nevertheless, the role of the alkyl chain in manipulating surface-limited crystal growth was not fully understood, preventing a further progress in interface control. In this study, we found that the length of the fluorine-substituted alkyl chain governed the crystal formation dynamics by manipulating surface tensions of different crystal orientations. The overall enhancement of the (001) plane, being the most favored, commonly resulted from the surface reformation of the perovskite film regardless of the chain length, while the highly oriented (001) over (111) was monitored with a particular chain length. The enhanced crystal orientation during surface recrystallization was responsible for the low trap density and thus effectively suppressed charge recombination at the interface, resulting in a considerable increase in open-circuit voltage and fill factor.
|
|
19. |
- Hu, Tianyu, et al.
(författare)
-
Steric hindrance induced low exciton binding energy enables low-driving-force organic solar cells
- 2024
-
Ingår i: Aggregate. - 2692-4560 .- 2766-8541. ; In Press
-
Tidskriftsartikel (refereegranskat)abstract
- Exciton binding energy (Eb) has been regarded as a critical parameter in charge separation during photovoltaic conversion. Minimizing the Eb of the photovoltaic materials can facilitate the exciton dissociation in low-driving force organic solar cells (OSCs) and thus improve the power conversion efficiency (PCE); nevertheless, diminishing the Eb with deliberate design principles remains a significant challenge. Herein, bulky side chain as steric hindrance structure was inserted into Y-series acceptors to minimize the Eb by modulating the intra- and intermolecular interaction. Theoretical and experimental results indicate that steric hindrance-induced optimal intra- and intermolecular interaction can enhance molecular polarizability, promote electronic orbital overlap between molecules, and facilitate delocalized charge transfer pathways, thereby resulting in a low Eb. The conspicuously reduced Eb obtained in Y-ChC5 with pinpoint steric hindrance modulation can minimize the detrimental effects on exciton dissociation in low-driving-force OSCs, achieving a remarkable PCE of 19.1% with over 95% internal quantum efficiency. Our study provides a new molecular design rationale to reduce the Eb.
|
|
20. |
- Khatri, C, et al.
(författare)
-
Outcomes after perioperative SARS-CoV-2 infection in patients with proximal femoral fractures: an international cohort study
- 2021
-
Ingår i: BMJ open. - : BMJ. - 2044-6055. ; 11:11, s. e050830-
-
Tidskriftsartikel (refereegranskat)abstract
- Studies have demonstrated high rates of mortality in people with proximal femoral fracture and SARS-CoV-2, but there is limited published data on the factors that influence mortality for clinicians to make informed treatment decisions. This study aims to report the 30-day mortality associated with perioperative infection of patients undergoing surgery for proximal femoral fractures and to examine the factors that influence mortality in a multivariate analysis.SettingProspective, international, multicentre, observational cohort study.ParticipantsPatients undergoing any operation for a proximal femoral fracture from 1 February to 30 April 2020 and with perioperative SARS-CoV-2 infection (either 7 days prior or 30-day postoperative).Primary outcome30-day mortality. Multivariate modelling was performed to identify factors associated with 30-day mortality.ResultsThis study reports included 1063 patients from 174 hospitals in 19 countries. Overall 30-day mortality was 29.4% (313/1063). In an adjusted model, 30-day mortality was associated with male gender (OR 2.29, 95% CI 1.68 to 3.13, p<0.001), age >80 years (OR 1.60, 95% CI 1.1 to 2.31, p=0.013), preoperative diagnosis of dementia (OR 1.57, 95% CI 1.15 to 2.16, p=0.005), kidney disease (OR 1.73, 95% CI 1.18 to 2.55, p=0.005) and congestive heart failure (OR 1.62, 95% CI 1.06 to 2.48, p=0.025). Mortality at 30 days was lower in patients with a preoperative diagnosis of SARS-CoV-2 (OR 0.6, 95% CI 0.6 (0.42 to 0.85), p=0.004). There was no difference in mortality in patients with an increase to delay in surgery (p=0.220) or type of anaesthetic given (p=0.787).ConclusionsPatients undergoing surgery for a proximal femoral fracture with a perioperative infection of SARS-CoV-2 have a high rate of mortality. This study would support the need for providing these patients with individualised medical and anaesthetic care, including medical optimisation before theatre. Careful preoperative counselling is needed for those with a proximal femoral fracture and SARS-CoV-2, especially those in the highest risk groups.Trial registration numberNCT04323644
|
|
21. |
- Kim, YeonJu, et al.
(författare)
-
Additives-free indolo[3,2-b]carbazole-based hole-transporting materials for perovskite solar cells with three yeses : Stability, efficiency, simplicity
- 2022
-
Ingår i: Nano Energy. - : Elsevier. - 2211-2855 .- 2211-3282. ; 101
-
Tidskriftsartikel (refereegranskat)abstract
- Indolo[3,2-b]carbazole-based hole transporting materials (HTM1-3) are developed for dopant-free pemvskite solar cells (PSCs). The newly synthesized compounds are studied as alternatives of conventional hole-transporting materials which typically require additives, are characterized by low resistivity to penetration of water, complicated synthesis and purification. The influence of substituents of derivatives of indolo[3,2-b]carbazole on their physical properties, e.g. ionization potentials, hole mobilities, the temperatures of thermal transitions, is investigated using experimental and theoretical tools. Ionization potentials in the order HTM2 < HTM1 < HTM3 indicate good energy level alignment with the valence band maximum of the pemvskite layer. Time-of-flight hole mobilities in the order HTM3 (5.26 x 10(-3) cm(2)V(-1)s(-1)) > HTM1 (1.1 x 10(-3) cm(2)V(-1)s(-1)) > HTM2 (0.55 x 10(-3) cm(2)V(-1)s(-1)) without additives indicate good hole transporting properties, principally stemming from their small degrees of energetic disorder following the order HTM3 (73.4 meV) similar to HTM2 (73.2 meV) > HTM1 (59.5 meV). The influence of different combinations of these parameters results in the different power conversion efficiencies of the developed dopant-free PSCs: [19.45% for the device containing HTM2] similar to [18.75% for PCS containing HTM3] > [14.46% for the device containing HTM1]. The devices demonstrate considerably higher stability and practically comparable efficiency as additives-containing reference PSCs with conventional hole-transporting material spiro-OMeTAD.
|
|
22. |
- Li, Chao, et al.
(författare)
-
Federated Hierarchical Trust-based Interaction Scheme for Cross-domain Industrial IoT
- 2023
-
Ingår i: IEEE Internet of Things Journal. - : IEEE. - 2327-4662 .- 2372-2541. ; 10:1, s. 447-457
-
Tidskriftsartikel (refereegranskat)abstract
- The Industrial Internet of Things (IIoT) is considered to be one of the most promising revolutionary technologies to increase productivity. With the refined development of manufacturing, the entire manufacturing process is split up into several areas of IoT production. Devices from different domains cooperate to perform the same task, which cause security problems in interacted communication among them. Existing authentication methods cause heavy key management overhead or rely on a trusted third party. It is imperative to protect privacy and ensure the credibility of the device during device interaction. This paper proposes a federated hierarchical trust interaction scheme (FHTI) for the cross-domain industrial IoT. It builds a low-privacy network platform through blockchain and protects the data privacy of the IIoT. A hierarchical trust mechanism based on federated detection is designed to realize the unified trust evaluation of cross-domain devices. A trusted cross-domain method based on device trust value is designed to ensure the security and trustworthiness of cross-domain devices. The simulation results show that the FHTI scheme can improve the speed of identity authentication and the detection accuracy of malicious devices.
|
|
23. |
- Li, Shangyu, et al.
(författare)
-
Tethered Small-Molecule Acceptors Simultaneously Enhance the Efficiency and Stability of Polymer Solar Cells
- 2023
-
Ingår i: Advanced Materials. - : WILEY-V C H VERLAG GMBH. - 0935-9648 .- 1521-4095. ; 35
-
Tidskriftsartikel (refereegranskat)abstract
- For polymer solar cells (PSCs), the mixture of polymer donors and small-molecule acceptors (SMAs) is fine-tuned to realize a favorable kinetically trapped morphology and thus a commercially viable device efficiency. However, the thermodynamic relaxation of the mixed domains within the blend raises concerns related to the long-term operational stability of the devices, especially in the record-holding Y-series SMAs. Here, a new class of dimeric Y6-based SMAs tethered with differential flexible spacers is reported to regulate their aggregation and relaxation behavior. In their polymer blends with PM6, it is found that they favor an improved structural order relative to that of Y6 counterpart. Most importantly, the tethered SMAs show large glass transition temperatures to suppress the thermodynamic relaxation in mixed domains. For the high-performing dimeric blend, an unprecedented open circuit voltage of 0.87 V is realized with a conversion efficiency of 17.85%, while those of regular Y6-base devices only reach 0.84 V and 16.93%, respectively. Most importantly, the dimer-based device possesses substantially reduced burn-in efficiency loss, retaining more than 80% of the initial efficiency after operating at the maximum power point under continuous illumination for 700 h. The tethering approach provides a new direction to develop PSCs with high efficiency and excellent operating stability.
|
|
24. |
- Lingard, Helen, et al.
(författare)
-
What have we learnt from the COVID-19 global pandemic: improving the construction industry’s abilities to foresee, respond to and recover from future endemic catastrophes (Special issue)
- 2021
-
Ingår i: Construction Management and Economics. - : Informa UK Limited. - 1466-433X .- 0144-6193. ; 39:2, s. 192-197
-
Tidskriftsartikel (refereegranskat)abstract
- Public health experts have strongly supported the need for companies to play their part in the global management of the COVID-19 pandemic, by providing training, screening, health surveillance and care. Occupational health and safety issues have become critical strategic concerns for organizations and industry sectors when making decisions about the management of business operations during the pandemic. There is emerging research documenting successful adaptations made by construction organisations to minimise the health and safety impacts of COVID-19, including modified work practices, flexible work arrangements, improved hygiene practices and welfare facilities. While the COVID-19 pandemic has created significant challenges for the construction industry, it has also prompted researchers and practitioners to reflect on the lessons that have been and continue to be learned and the role that the effective management of health, safety and well-being has played (and can continue to play) in ensuring organizational resilience and business continuity. The aim of this special issue is to analyse, understand and document the way in which construction industries across the globe have responded to and experienced (and continue to experience) the COVID-19 pandemic, as well as what they have learnt during this extraordinary period. The special issue seeks to collate evidence as to what worked well and what did not, and why, and to identify and share lessons learned in relation to strengthening the global construction industry’s risk governance mechanisms, bolstering organizational resilience and reducing vulnerability to transboundary crises that might arise in the future. This special issue focuses on the variety and effectiveness of health and safety management responses at: macro (industry/policy), meso (organizational/project) and micro (workgroup/individual) levels implemented by the global construction industry in response to the COVID-19 pandemic.
|
|
25. |
|
|
26. |
|
|
27. |
- Suo, Jiajia, et al.
(författare)
-
Interfacial engineering from material to solvent : A mechanistic understanding on stabilizing alpha-formamidinium lead triiodide perovskite photovoltaics
- 2022
-
Ingår i: Nano Energy. - : Elsevier. - 2211-2855 .- 2211-3282. ; 94
-
Tidskriftsartikel (refereegranskat)abstract
- Formamidinium lead triiodide (FAPbI3) has recently been considered as the most promising candidate to achieve highly efficient perovskite solar cells (PSCs). Excitingly, the state-of-the-art highest efficiency of FAPbI3 based PSCs have reached over 25%. However, their device stability still lags behind other compositions of mixed-cation and mixed-halide perovskites. Interfacial engineering is a very powerful method to address this issue and passivation agents have been intensively developed, however there is a lack of in-depth understanding regarding the solvent selection during post-treatment. Here, we employed cyclohexylmethylammonium iodide (CMAI) as passivation agent, which is investigated using either isopropanol (IPA) or chloroform (CF) as carrier mediator to study the solvent influence on the stabilization of FAPbI3. We observed a suppressed-defect perovskite surface toward distinguished composition with 2D CMA2PbI4 domain and CMAI domain induced by IPA and CF, respectively. Remarkably, post-treatment with solution of CMAI in CF creates a strain-free environment on the perovskite surface, leading to an improved efficiency of approaching 24% and concurrently an extraordinarily stable alpha-phase FAPbI3 PSCs under operation condition, retaining 95% of its initial efficiency after 1050-hour aging. Our resulting device stability is one of the most stable FAPbI3 based PSCs reported in literature.
|
|
28. |
- Suo, Jiajia, et al.
(författare)
-
Multifunctional sulfonium-based treatment for perovskite solar cells with less than 1% efficiency loss over 4,500-h operational stability tests
- 2024
-
Ingår i: Nature Energy. - : NATURE PORTFOLIO. - 2058-7546.
-
Tidskriftsartikel (refereegranskat)abstract
- The stabilization of grain boundaries and surfaces of the perovskite layer is critical to extend the durability of perovskite solar cells. Here we introduced a sulfonium-based molecule, dimethylphenethylsulfonium iodide (DMPESI), for the post-deposition treatment of formamidinium lead iodide perovskite films. The treated films show improved stability upon light soaking and remains in the black alpha phase after two years ageing under ambient condition without encapsulation. The DMPESI-treated perovskite solar cells show less than 1% performance loss after more than 4,500 h at maximum power point tracking, yielding a theoretical T80 of over nine years under continuous 1-sun illumination. The solar cells also display less than 5% power conversion efficiency drops under various ageing conditions, including 100 thermal cycles between 25 degrees C and 85 degrees C and an 1,050-h damp heat test. Suo et al. show that sulfonium-based molecules afford formamidinium lead iodide perovskites protection against environmental stress factors, improved phase stability and solar cells retaining efficiency over 4,500-h operational stability tests.
|
|
29. |
- Suo, Jiajia, et al.
(författare)
-
Passivation Strategies through Surface Reconstruction toward Highly Efficient and Stable Perovskite Solar Cells on n-i-p Architecture
- 2021
-
Ingår i: Energies. - : MDPI. - 1996-1073. ; 14:16
-
Forskningsöversikt (refereegranskat)abstract
- Perovskite solar cells have achieved remarkable enhancement in their performance in recent years. However, to get an entrance to the photovoltaic market, great effort is still necessary to further improve their efficiency as well as their long-term stability under various conditions. Among various types of approaches (including compositional engineering, dopant engineering, self-assembled monolayers (SAMs), et al.), interfacial engineering through passivation treatment has been considered as one of the most effective strategies to reduce the non-radiative recombination within the PSCs. Thus, this short review summaries recent efforts on chemical interfacial passivation strategies from a different perspective owing to their common phenomena of reconstructing the perovskite surface via the formation of three-dimensional perovskite, low-dimensional perovskite and synergistic effect provided by a mixed-salt passivation system, respectively.
|
|
30. |
- Suo, Jiajia, et al.
(författare)
-
Surface Reconstruction Engineering with Synergistic Effect of Mixed-Salt Passivation Treatment toward Efficient and Stable Perovskite Solar Cells
- 2021
-
Ingår i: Advanced Functional Materials. - : John Wiley & Sons. - 1616-301X .- 1616-3028. ; 31:34
-
Tidskriftsartikel (refereegranskat)abstract
- Surface passivation treatment is a widely used strategy to resolve trap-mediated nonradiative recombination toward high-efficiency metal-halide perovskite photovoltaics. However, a lack of passivation with mixture treatment has been investigated, as well as an in-depth understanding of its passivation mechanism. Here, a systematic study on a mixed-salt passivation strategy of formamidinium bromide (FABr) coupled with different F-substituted alkyl lengths of ammonium iodide is demonstrated. It is obtained better device performance with decreasing chain length of the F-substituted alkyl ammonium iodide in the presence of FABr. Moreover, they unraveled a synergistic passivation mechanism of the mixed-salt treatment through surface reconstruction engineering, where FABr dominates the reformation of the perovskite surface via reacting with the excess PbI2. Meanwhile, ammonium iodide passivates the perovskite grain boundaries both on the surface and top perovskite bulk through penetration. This synergistic passivation engineer results in a high-quality perovskite surface with fewer defects and suppressed ion migration, leading to a champion efficiency of 23.5% with mixed-salt treatment. In addition, the introduction of the moisture resisted F-substituted groups presents a more hydrophobic perovskite surface, thus enabling the decorated devices with excellent long-term stability under a high humid atmosphere as well as operational conditions.
|
|
31. |
- Vesce, Luigi, et al.
(författare)
-
Hysteresis-Free Planar Perovskite Solar Module with 19.1% Efficiency by Interfacial Defects Passivation
- 2022
-
Ingår i: Solar RRL. - : John Wiley & Sons. - 2367-198X. ; 6:7
-
Tidskriftsartikel (refereegranskat)abstract
- In few years, perovskite solar devices have reached high efficiency on lab scale cells. Upscaling to module size, effective perovskite recipe and posttreatment are of paramount importance to the breakthrough of the technology. Herein this work, the development of a low-temperature planar n-i-p perovskite module (11 cm(2) aperture area, 91% geometrical fill factor) is reported on, exploiting the defect passivation strategy to achieve an efficiency of 19.1% (2% losses stabilized) with near-zero hysteresis, that is the most unsolved issue in the perovskite photovoltaic technology. The I/Br (iodine/bromide) halide ion ratio of the triple-cation perovskite formulation and deposition procedure are optimized to move from small area to module device and to avoid the detrimental effect of dimethyl sulfoxide (DMSO) solvent. The organic halide salt phenethylammonium iodide (PEAI) is adopted as surface passivation material on module size to suppress perovskite defects. Finally, homogeneous and defect-free layers from cell to module with only 8% relative efficiency losses, high reproducibility, and optimized interconnections are scaled by laser ablation methods. The homogeneity of the perovskite layers and of the full stack was assessed by optical, morphological, and light beam-induced current (LBIC) mapping characterizations.
|
|
32. |
- Wagner, Lukas, et al.
(författare)
-
The resource demands of multi-terawatt-scale perovskite tandem photovoltaics
- 2024
-
Ingår i: Joule. - : Elsevier. - 2542-4351. ; 8:4, s. 1142-1160
-
Tidskriftsartikel (refereegranskat)abstract
- Photovoltaics (PV) and wind are the most important energy -conversion technologies for cost-efficient climate change mitigation. To reach international climate goals, the annual PV module production must be expanded to multi-terawatt (TW) scale. Economic and resource restraints demand the implementation of cost-efficient multi -junction technologies, for which perovskite-based tandem technologies are highly promising. In this work, the resource demand of the emerging perovskite PV technology is investigated, considering two factors of supply criticality, namely, mining capacity for minerals and the production capacity for synthetic materials. Overall, the expansion of perovskite PV to a multi-TW scale may not be limited by material supply if certain materials, especially indium, can be replaced. Moreover, organic charge -transport materials face currently unresolved scalability challenges. This study demonstrates that, besides the improvement of efficiency and stability, perovskite PV research and development also need to be guided by sustainable materials choices and design -for -recycling considerations.
|
|
33. |
- Yang, Bowen, et al.
(författare)
-
A universal ligand for lead coordination and tailored crystal growth in perovskite solar cells
- 2024
-
Ingår i: Energy & Environmental Science. - : Royal Society of Chemistry. - 1754-5692 .- 1754-5706. ; 17:4, s. 1549-1558
-
Tidskriftsartikel (refereegranskat)abstract
- Chemical environment and precursor-coordinating molecular interactions within a perovskite precursor solution can lead to important implications in structural defects and crystallization kinetics of a perovskite film. Thus, the opto-electronic quality of such films can be boosted by carefully fine-tuning the coordination chemistry of perovskite precursors via controllable introduction of additives, capable of forming intermediate complexes. In this work, we employed a new type of ligand, namely 1-phenylguanidine (PGua), which coordinates strongly with the PbI2 complexes in the perovskite precursor, forming new intermediate species. These strong interactions effectively retard the perovskite crystallization process and form homogeneous films with enlarged grain sizes and reduced density of defects. In combination with an interfacial treatment, the resulted champion devices exhibit a 24.6% efficiency with outstanding operational stability. Unprecedently, PGua can be applied in various PSCs with different perovskite compositions and even in both configurations: n-i-p and p-i-n, highlighting the universality of this ligand.
|
|
34. |
- Yang, Bowen, et al.
(författare)
-
Interfacial Passivation Engineering of Perovskite Solar Cells with Fill Factor over 82% and Outstanding Operational Stability on n-i-p Architecture
- 2021
-
Ingår i: ACS Energy Letters. - : American Chemical Society (ACS). - 2380-8195. ; 6:11, s. 3916-3923
-
Tidskriftsartikel (refereegranskat)abstract
- Tremendous efforts have been dedicated toward minimizing the open-circuit voltage deficits on perovskite solar cells (PSCs), and the fill factors are still relatively low. This hinders their further application in large scalable modules. Herein, we employ a newly designed ammonium salt, cyclohexylethylammonium iodide (CEAI), for interfacial engineering between the perovskite and hole-transporting layer (HTL), which enhanced the fill factor to 82.6% and consequent PCE of 23.57% on the target device. This can be associated with a reduction of the trap-assisted recombination rate at the 3D perovskite surface, via formation of a 2D perovskite interlayer. Remarkably, the property of the 2D perovskite interlayer along with the cyclohexylethyl group introduced by CEAI treatment also determines a pronounced enhancement in the surface hydrophobicity, leading to an outstanding stability of over 96% remaining efficiency of the passivated devices under maximum power point tracking with one sun illumination under N-2 atmosphere at room temperature after 1500 h.
|
|
35. |
- Yang, Bowen, et al.
(författare)
-
Strain effects on halide perovskite solar cells
- 2022
-
Ingår i: Chemical Society Reviews. - : Royal Society of Medicine Press. - 0306-0012 .- 1460-4744. ; 51:17, s. 7509-7530
-
Forskningsöversikt (refereegranskat)abstract
- Halide perovskite solar cells (PSCs) have achieved power conversion efficiencies (PCEs) approaching 26%, however, the stability issue hinders their commercialization. Due to the soft ionic nature of perovskite materials, the strain effect on perovskite films has been recently recognized as one of the key factors that affects their opto-electronic properties and the device stability. Herein, we summarized the origins of strain, characterization techniques, and implications of strain on both perovskite film and solar cells as well as various strategies to control the strain. Finally, we proposed effective strategies for future strain engineering. We believe this comprehensive review could further facilitate researchers with a deeper understanding of strain effect and enhance the research activity in engineering the strain to further improve performance and especially the device stability toward commercialization.
|
|
36. |
- Yang, Hui, et al.
(författare)
-
BrainIoT : Brain-Like Productive Services Provisioning with Federated Learning in Industrial IoT
- 2022
-
Ingår i: IEEE Internet of Things Journal. - : IEEE. - 2327-4662. ; 9:3, s. 2014-2024
-
Tidskriftsartikel (refereegranskat)abstract
- The Industrial Internet of Things (IIoT) accommodates a huge number of heterogeneous devices to bring vast services under a distributed computing scenarios. Most productive services in IIoT are closely related to production control and require distributed network support with low delay. However, the resource reservation based on gross traffic prediction ignores the importance of productive services and treats them as ordinary services, so it is difficult to provide stable low delay support for large amounts of productive service requests. For many productions, unexpected communication delays are unacceptable, and the delay may lead to serious production accidents causing great losses, especially when the productive service is security related. In this article, we propose a brain-like productive service provisioning scheme with federated learning (BrainIoT) for IIoT. The BrainIoT scheme is composed of three algorithms, including industrial knowledge graph-based relation mining, federated learning-based service prediction, and globally optimized resource reservation. BrainIoT combines production information into network optimization, and utilizes the interfactory and intrafactory relations to enhance the accuracy of service prediction. The globally optimized resource reservation algorithm suitably reserves resources for predicted services considering various resources. The numerical results show that the BrainIoT scheme utilizes interfactory relation and intrafactory relation to make an accurate service prediction, which achieves 96% accuracy, and improves the quality of service.
|
|
37. |
- Zhang, Ming, et al.
(författare)
-
Tethered Small-Molecule Acceptor Refines Hierarchical Morphology in Ternary Polymer Solar Cells: Enhanced Stability and 19% Efficiency
- 2023
-
Ingår i: Advanced Materials. - : WILEY-V C H VERLAG GMBH. - 0935-9648 .- 1521-4095.
-
Tidskriftsartikel (refereegranskat)abstract
- Polymer solar cells (PSCs) are promising for efficient solar energy conversion, but achieving high efficiency and device longevity within a bulk-heterojunction (BHJ) structure remains a challenge. Traditional small-molecule acceptors (SMAs) in the BHJ blend show thermodynamic instability affecting the morphology. In contrast, tethered SMAs exhibit higher glass transition temperatures, mitigating these concerns. Yet, they might not integrate well with polymer donors, causing pronounced phase separation and overpurification of mixed domains. Herein, a novel ternary device is introduced that uses DY-P2EH, a tethered dimeric SMA with conjugated side-chains as host acceptor, and BTP-ec9, a monomeric SMA as secondary acceptor, which respectively possess hypomiscibility and hypermiscibility with the polymer donor PM6. This unique combination affords a parallel-connected ternary BHJ blend, leading to a hierarchical and stable morphology. The ternary device achieves a remarkable fill factor of 80.61% and an impressive power conversion efficiency of 19.09%. Furthermore, the ternary device exhibits exceptional stability, retaining over 85% of its initial efficiency even after enduring 1100 h of thermal stress at 85 degrees C. These findings highlight the potential advantage of tethered SMAs in the design of ternary devices with a refined hierarchical structure for more efficient and durable solar energy conversion technologies. A ternary-device design is proposed that fully utilizes the individual thermodynamic properties of both dimeric acceptor and monomeric acceptor. The high Tg value of dimeric acceptor significantly impedes the molecular movement of monomeric acceptor, while hypermiscible properties of monomeric acceptor promote percolation of the mixed domain for enhancing charge dynamics.image
|
|
38. |
- Zhang, Y., et al.
(författare)
-
A comprehensive review on self-powered smart bearings
- 2023
-
Ingår i: Renewable & sustainable energy reviews. - : Elsevier. - 1364-0321 .- 1879-0690. ; 183
-
Forskningsöversikt (refereegranskat)abstract
- Recently, with the development of industrial informatization and intellectualization, the development of smart bearings has attracted a lot of significant attention in an attempt to reduce maintenance costs and increase reliability by providing online health condition monitoring. As a result of advances in miniaturization and low power consumption of wireless sensor nodes (WSNs), self-powered technologies have been considered as a promising method to achieve autonomous WSNs in smart bearings. Although the self-powered technology has received considerable achievements, there are less reviews covering the development of self-powered structures towards smart bearing and providing potential guidelines for the future development. To bridge the gap, this paper presents a comprehensive state-of-the-art review and guidelines on self-powered methods to create smart bearings, including outlining the underlying theory, modeling methods, methodologies and technologies. The topology of a self-powered smart bearing is clarified, and the mechanisms and benefits of piezoelectricity, electromagnetism, triboelectricity, thermoelectricity and wireless power transfer for powering WSNs in smart bearing are discussed. To improve the applicability of self-powered smart bearing in a range of working conditions, the design methodologies and technologies of a variety of transducers are reviewed to provide guidelines for performance enhancement. Finally, the future challenges and perspectives are proposed for outlining potential research directions and opportunities in future self-powered smart bearing systems, including the impact on bearing performance, engineering implementation, reliability, power management and storage.
|
|
39. |
- Zhang, Youzi, et al.
(författare)
-
Gradient Heating Epitaxial Growth Gives Well Lattice-Matched Mo2C-Mo2N Heterointerfaces that Boost Both Electrocatalytic Hydrogen Evolution and Water Vapor Splitting
- 2022
-
Ingår i: Angewandte Chemie International Edition. - : Wiley-Blackwell. - 1433-7851 .- 1521-3773. ; 61:47
-
Tidskriftsartikel (refereegranskat)abstract
- An optimized approach to producing lattice-matched heterointerfaces for electrocatalytic hydrogen evolution has not yet been reported. Herein, we present the synthesis of lattice-matched Mo2C-Mo2N heterostructures using a gradient heating epitaxial growth method. The well lattice-matched heterointerface of Mo2C-Mo2N generates near-zero hydrogen-adsorption free energy and facilitates water dissociation in acid and alkaline media. The lattice-matched Mo2C-Mo2N heterostructures have low overpotentials of 73 mV and 80 mV at 10 mA cm(-2) in acid and alkaline solutions, respectively, comparable to commercial Pt/C. A novel photothermal-electrocatalytic water vapor splitting device using the lattice-matched Mo2C-Mo2N heterostructure as a hydrogen evolution electrocatalyst displays a competitive cell voltage for electrocatalytic water splitting.
|
|