| 1. |
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| 2. |
- Klionsky, Daniel J., et al.
(författare)
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Guidelines for the use and interpretation of assays for monitoring autophagy
- 2012
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Ingår i: Autophagy. - : Informa UK Limited. - 1554-8635 .- 1554-8627. ; 8:4, s. 445-544
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Forskningsöversikt (refereegranskat)abstract
- In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.
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| 3. |
- Kristan, Matej, et al.
(författare)
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The Ninth Visual Object Tracking VOT2021 Challenge Results
- 2021
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Ingår i: 2021 IEEE/CVF INTERNATIONAL CONFERENCE ON COMPUTER VISION WORKSHOPS (ICCVW 2021). - : IEEE COMPUTER SOC. - 9781665401913 ; , s. 2711-2738
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Konferensbidrag (refereegranskat)abstract
- The Visual Object Tracking challenge VOT2021 is the ninth annual tracker benchmarking activity organized by the VOT initiative. Results of 71 trackers are presented; many are state-of-the-art trackers published at major computer vision conferences or in journals in recent years. The VOT2021 challenge was composed of four sub-challenges focusing on different tracking domains: (i) VOT-ST2021 challenge focused on short-term tracking in RGB, (ii) VOT-RT2021 challenge focused on "real-time" short-term tracking in RGB, (iii) VOT-LT2021 focused on long-term tracking, namely coping with target disappearance and reappearance and (iv) VOT-RGBD2021 challenge focused on long-term tracking in RGB and depth imagery. The VOT-ST2021 dataset was refreshed, while VOT-RGBD2021 introduces a training dataset and sequestered dataset for winner identification. The source code for most of the trackers, the datasets, the evaluation kit and the results along with the source code for most trackers are publicly available at the challenge website(1).
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| 4. |
- Weinstein, John N., et al.
(författare)
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The cancer genome atlas pan-cancer analysis project
- 2013
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 45:10, s. 1113-1120
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Forskningsöversikt (refereegranskat)abstract
- The Cancer Genome Atlas (TCGA) Research Network has profiled and analyzed large numbers of human tumors to discover molecular aberrations at the DNA, RNA, protein and epigenetic levels. The resulting rich data provide a major opportunity to develop an integrated picture of commonalities, differences and emergent themes across tumor lineages. The Pan-Cancer initiative compares the first 12 tumor types profiled by TCGA. Analysis of the molecular aberrations and their functional roles across tumor types will teach us how to extend therapies effective in one cancer type to others with a similar genomic profile. © 2013 Nature America, Inc. All rights reserved.
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| 5. |
- Benter, Sandra, et al.
(författare)
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Tuneable 2D surface Bismuth incorporation on InAs nanosheets
- 2023
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Ingår i: Nanoscale. - : Royal Society of Chemistry. - 2040-3364 .- 2040-3372. ; 15:21, s. 9551-9559
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Tidskriftsartikel (refereegranskat)abstract
- The chemical bonding at the interface between compound semiconductors and metals is central in determining electronic and optical properties. In this study, new opportunities for controlling this are presented for nanostructures. We investigate Bi adsorption on 2D wurtzite InAs (1120) nanosheets and find that temperature-controlled Bi incorporation in either anionic- or cationic-like bonding is possible in the easily accesible range between room temperature and 400 degrees C. This separation could not be achieved for ordinary zinc blende InAs(110) surfaces. As the crystal structures of the two surfaces have identical nearest neighbour configurations, this indicates that overall geometric differences can significantly alter the adsorption and incorporation. Ab initio theoretical modelling confirms observed adsorption results, but indicate that both the formation energies as well as kinetic barriers contributes to the observed temperature dependent behaviour. Further, we find that the Bi adsorption rate can differ by at least 2.5 times between the two InAs surfaces while being negligible for standard Si substrates under similar deposition conditions. This, in combination with the observed interface control, provides an excellent opportunity for tuneable Bi integration on 2D InAs nanostructures on standard Si substrates.
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| 6. |
- Chen, Jingxuan, et al.
(författare)
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Regulating Thiol Ligands of p-Type Colloidal Quantum Dots for Efficient Infrared Solar Cells
- 2021
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Ingår i: ACS Energy Letters. - : American Chemical Society (ACS). - 2380-8195. ; 6:5, s. 1970-1989
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Tidskriftsartikel (refereegranskat)abstract
- The p-type semiconducting colloidal quantum dot (CQD), working as a hole conductor in CQD solar cells (CQDSCs), is critical for charge carrier extraction and therefore, to large extent, determines the device's photovoltaic performance. However, during the preparation of a p-type CQD solid film on the top of an n-type CQD solid film, forming a p-n heterojunction within the CQDSCs, the optoelectronic properties of the underlayered n-type CQD solid film are significantly affected by conventional 1,2-ethanedithiol (EDT) ligands due to its high reactivity. Herein, a series of thiol ligands are comprehensively studied for p-type CQDs, which suggests that, by finely controlling the interaction between the CQDs and thiol ligands during the preparation of p-type CQD solid films, the n-type CQD solid films can be well protected and avoid destruction induced by thiol ligands. The p-type CQD solid film with 4-aminobenzenethiol (ABT) passivating the CQD surface exhibits better optoelectronic properties than the conventional p-type EDT-based CQD solid films, resulting in an improved photovoltaic performance in CQDSCs.
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| 7. |
- Liu, Tao, et al.
(författare)
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16% efficiency all-polymer organic solar cells enabled by a finely tuned morphology via the design of ternary blend
- 2021
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Ingår i: Joule. - : CELL PRESS. - 2542-4351. ; 5:4, s. 914-930
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Tidskriftsartikel (refereegranskat)abstract
- A SUMMARY There is an urgent demand for all-polymer organic solar cells (AP-OSCs) to gain higher efficiency. Here, we successfully improve the performance to 16.09% by introducing a small amount of BN-T, a B <- N-type polymer acceptor, into the PM6:PY-IT blend. It has been found that BN-T makes the active layer, based on the PM6:PY-IT:BN-T ternary blend, more crystalline but meanwhile slightly reduces the phase separation, leading to enhancement of both exciton harvesting and charge transport. From a thermodynamic viewpoint, BN-T prefers to reside between PM6 and PY-IT, and the fraction of this fine-tunes the morphology. Besides, a significantly reduced nonradiative energy loss occurs in the ternary blend, along with the coexistence of energy and charge transfer between the two acceptors. The progressive performance facilitated by these improved properties demonstrates that AP-OSCs can possibly comparably efficient with those based on small molecule acceptors, further enhancing the competitiveness of this device type.
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| 8. |
- Ren, Zhenjing, et al.
(författare)
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Tetratricopeptide-containing SMALL KERNEL 11 is essential for the assembly of cytochrome c oxidase in maize mitochondria
- 2023
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Ingår i: Plant Physiology. - : Oxford University Press (OUP). - 0032-0889 .- 1532-2548. ; 192:1, s. 170-187
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Tidskriftsartikel (refereegranskat)abstract
- Assembly of the functional complexes of the mitochondrial respiratory chain requires sophisticated and efficient regulatory mechanisms. In plants, the subunit composition and assembly factors involved in the biogenesis of cytochrome c oxidase (complex IV) are substantially less defined than in mammals and yeast. In this study, we cloned maize (Zea mays) Small kernel 11 (Smk11) via map-based cloning. Smk11 encodes a mitochondria-localized tetratricopeptide repeat protein. Disruption of Smk11 severely affected the assembly and activity of mitochondrial complex IV, leading to delayed plant growth and seed development. Protein interactions studies revealed that SMK11 might interact with four putative complex IV assembly factors, Inner membrane peptidase 1A (ZmIMP1A), MYB domain protein 3R3 (ZmMYB3R-3), cytochrome c oxidase 23 (ZmCOX23), and mitochondrial ferredoxin 1 (ZmMFDX1), among which ZmMFDX1 might interact with subunits ZmCOX6a and ZmCOX-X1; ZmMYB3R-3 might also interact with ZmCOX6a. The mutation of SMK11 perturbed the normal assembly of these subunits, leading to the inactivation of complex IV. The results of this study revealed that SMK11 serves as an accessory assembly factor required for the normal assembly of subunits into complex IV, which will accelerate the elucidation of the assembly of complex IV in plant mitochondria.
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| 9. |
- Wei, Jianhua, et al.
(författare)
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Genome and proteomic analysis of risk factors for fatal outcome in children with severe community-acquired pneumonia caused by human adenovirus 7
- 2023
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Ingår i: Journal of Medical Virology. - : WILEY. - 0146-6615 .- 1096-9071. ; 95:11
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Human adenovirus 7 (HAdV-7) is an important viral pathogen of severe pneumonia in children and a serious threat to health. Methods: A cohort of 45 pediatric patients diagnosed with HAdV-7-associated severe pneumonia and admitted to the Pediatric Intensive Care Unit at the Children's Hospital of Chongqing Medical University from May 2018 to January 2020 were included. Risk factors of death were analyzed by the Cox proportional risk mode with Clinical data, serum, and nasopharyngeal aspirate adenovirus load, Genome analysis, Olink proteomics, and cytokine profile between dead and surviving patients were also analyzed. Results: A total of 45 children with a median age of 12.0 months (interquartile range [IQR]: 6.5, 22.0) were included (female 14), including 14 (31.1%) who died. High serum viral load was an independent risk factor for mortality (hazard ratio [HR] = 2.16, 95% confidence interval [CI], 1.04-4.49, p = 0.039). BTB and CNC homology 1 (BACH1), interleukin-5 (IL-5), and IL-9 levels were significantly correlated with serum viral load (p = 0.0400, 0.0499, and 0.0290; r = 0.4663, 0.3339, and -0.3700, respectively), with significant differences between the dead and survival groups (p = 0.021, 0.001, and 0.021). Conclusions: Severe cytokine storm-associated high serum viral load after HAdV-7 infection may be the main mechanism responsible for poor prognosis in children.
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| 10. |
- Feng, Kui, et al.
(författare)
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Fused Bithiophene Imide Dimer-Based n-Type Polymers for High-Performance Organic Electrochemical Transistors
- 2021
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Ingår i: Angewandte Chemie International Edition. - : WILEY-V C H VERLAG GMBH. - 1433-7851 .- 1521-3773. ; 60:45, s. 24198-24205
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Tidskriftsartikel (refereegranskat)abstract
- The development of n-type organic electrochemical transistors (OECTs) lags far behind their p-type counterparts. In order to address this dilemma, we report here two new fused bithiophene imide dimer (f-BTI2)-based n-type polymers with a branched methyl end-capped glycol side chain, which exhibit good solubility, low-lying LUMO energy levels, favorable polymer chain orientation, and efficient ion transport property, thus yielding a remarkable OECT electron mobility (mu(e)) of up to approximate to 10(-2) cm(2) V-1 s(-1) and volumetric capacitance (C*) as high as 443 F cm(-3), simultaneously. As a result, the f-BTI2TEG-FT-based OECTs deliver a record-high maximum geometry-normalized transconductance of 4.60 S cm(-1) and a maximum mu C* product of 15.2 F cm(-1) V-1 s(-1). The mu C* figure of merit is more than one order of magnitude higher than that of the state-of-the-art n-type OECTs. The emergence of f-BTI2TEG-FT brings a new paradigm for developing high-performance n-type polymers for low-power OECT applications.
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| 11. |
- Guangnan, Huang, et al.
(författare)
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Velocity Tomography Imaging Method with Variable Grid spacing/Interval
- 2013
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Ingår i: Oil Geophysical Prospecting. - 1000-7210. ; 48:3, s. 379-389
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Tidskriftsartikel (refereegranskat)abstract
- In variable grid spacing tomography the underground velocity distribution is parameterized with model cells of different sizes. This method can simultaneously take into account the spatially varying resolution inherent in most datasets. E.g., due to experimental design or logistic constraints, the shallow and deep subsurface velocity distribution may be very differently determined by the available data. The variable grid spacing tomography and regular grid spacing tomography are similar in most other aspects. There are two main differences between the variable grid spacing method and the regular grid spacing method. First, ray segments calculated in the forward model cells should be divided into the larger cells of the inversion model. Second, the smoothness constraint equations needed to inhibit wild velocity variations need to be modified where the cells change in size. In a synthetic checkerboard reconstruction test with differently sized checkers the variable grid spacing method recovers the small and large checkers better than the regular grid spacing method in both two and three-dimensional test cases. For a real dataset, the variable grid spacing method distinguishes two low velocity zones better than the regular grid spacing method. Finally, it can be concluded that when the effort is spent to identify the regions in a model with best data coverage, the variable grid spacing method can produce velocity images with higher fidelity than when a uniform cell size is used. Especially, in many cases this method can enhance the fidelity of the shallow subsurface velocity distribution. In addition, variable grid spacing tomography can reduce the underdetermined regions in an inverse problem when the data coverage is irregular.
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| 12. |
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| 13. |
- Jia, Donglin, et al.
(författare)
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Dual Passivation of CsPbI3 Perovskite Nanocrystals with Amino Acid Ligands for Efficient Quantum Dot Solar Cells
- 2020
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Ingår i: Small. - : WILEY-V C H VERLAG GMBH. - 1613-6810 .- 1613-6829. ; 16:24
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Tidskriftsartikel (refereegranskat)abstract
- Inorganic CsPbI3 perovskite quantum dot (PQD) receives increasing attention for the application in the new generation solar cells, but the defects on the surface of PQDs significantly affect the photovoltaic performance and stability of solar cells. Herein, the amino acids are used as dual-passivation ligands to passivate the surface defects of CsPbI3 PQDs using a facile single-step ligand exchange strategy. The PQD surface properties are investigated in depth by combining experimental studies and theoretical calculation approaches. The PQD solid films with amino acids as dual-passivation ligands on the PQD surface are thoroughly characterized using extensive techniques, which reveal that the glycine ligand can significantly improve defect passivation of PQDs and therefore diminish charge carrier recombination in the PQD solid. The power conversion efficiency (PCE) of the glycine-based PQD solar cell (PQDSC) is improved by 16.9% compared with that of the traditional PQDSC fabricated with Pb(NO3)(2) treating the PQD surface, owning to improved charge carrier extraction. Theoretical calculations are carried out to comprehensively understand the thermodynamic feasibility and favorable charge density distribution on the PQD surface with a dual-passivation ligand.
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| 14. |
- Jia, Donglin, et al.
(författare)
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Highly Stabilized Quantum Dot Ink for Efficient Infrared Light Absorbing Solar Cells
- 2019
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Ingår i: Advanced Energy Materials. - : WILEY-V C H VERLAG GMBH. - 1614-6832 .- 1614-6840. ; 9:44
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Tidskriftsartikel (refereegranskat)abstract
- Liquid-state ligand exchange provides an efficient approach to passivate a quantum dot (QD) surface with small binding species and achieve a QD ink toward scalable QD solar cell (QDSC) production. Herein, experimental studies and theoretical simulations are combined to establish the physical principles of QD surface properties induced charge carrier recombination and collection in QDSCs. Ammonium iodide (AI) is used to thoroughly replace the native oleic acid ligand on the PbS QD surface forming a concentrated QD ink, which has high stability of more than 30 d. The ink can be directly applied for the preparation of a thick QD solid film using a single deposition step method and the QD solid film shows better characteristics compared with that of the film prepared with the traditional PbX2 (X = I or Br) post-treated QD ink. Infrared light-absorbing QDSC devices are fabricated using the PbS-AI QD ink and the devices give a higher photovoltaic performance compared with the devices fabricated with the traditional PbS-PbX2 QD ink. The improved photovoltaic performance in PbS-AI-based QDSC is attributed to diminished charge carrier recombination induced by the sub-bandgap traps in QDs. A theoretical simulation is carried out to atomically link the relationship of QDSC device function with the QD surface properties.
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| 15. |
- Liu, Jianhua, et al.
(författare)
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Differential space-code modulation for interference suppression
- 2001
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Ingår i: IEEE Transactions on Signal Processing. - : Institute of Electrical and Electronics Engineers (IEEE). - 1053-587X .- 1941-0476. ; 49:8, s. 1786-1795
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Tidskriftsartikel (refereegranskat)abstract
- Space-time coding has been receiving much attention due to its potentials offered by fully exploiting the spatial and temporal diversities of multiple transmit and receive antennas. A differential space-time modulation (DSTM) scheme was previously proposed for demodulation without channel state information, which is attractive in fast fading channels where accurate channel estimates are difficult to obtain. However, this technique is sensitive to interference and is likely to deteriorate or even break down in a wireless environment, where interference (including intentional and unintentional jamming) signals exist. We propose a new coding and modulation scheme, referred to as the differential space-code modulation (DSCM), which is interference resistant. Our focus is on single-user communications. We show that DSCM outperforms DSTM significantly when interference is present. This advantage is achieved at the cost of a lower data rate or a wider bandwidth or a combination of both. To alleviate this problem, a high-rate DSCM (HR-DSCM) scheme is also presented, which increases the data rate considerably at the cost of a slightly higher bit-error rate (BER), while still maintaining the interference suppression capability.
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| 16. |
- Liu, Jianhua, et al.
(författare)
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Differential space-time block code modulation for DS-CDMA systems
- 2002
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Ingår i: EURASIP Journal on Advances in Signal Processing. - 1687-6172 .- 1687-6180. ; :3, s. 289-296
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Tidskriftsartikel (refereegranskat)abstract
- A differential space-time block code (DSTBC) modulation scheme is used to improve the performance of DS-CDMA systems in fast time-dispersive fading channels. The resulting scheme is referred to as the differential space-time block code modulation for DS-CDMA (DSTBC-CDMA) systems. The new modulation and demodulation schemes are especially studied for the down-link transmission of DS-CDMA systems. We present three demodulation schemes, referred to as the differential space-time block code Rake (D-Rake) receiver, differential space-time block code deterministic (D-Det) receiver, and differential space-time block code deterministic de-prefix (D-Det-DP) receiver, respectively. The D-Det receiver exploits the known information of the spreading sequences and their delayed paths deterministically besides the Rake type combination; consequently, it can outperform the D-Rake receiver, which employs the Rake type combination only. The D-Det-DP receiver avoids the effect of intersymbol interference and hence can offer better performance than the D-Det receiver.
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| 17. |
- Liu, Jianhua, et al.
(författare)
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High-rate differential space-code modulation for interference suppression
- 2001
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Ingår i: 2001 IEEE Third Workshop on Signal Processing Advances in Wireless Communications (SPAWC'01). Workshop Proceedings. - 0780367200 ; , s. 283-286
-
Konferensbidrag (refereegranskat)abstract
- Space-time coding has been receiving much research attention recently due to the potential offered by fully exploiting spatial and temporal diversity. A differential space-time modulation (DSTM) scheme was recently proposed to perform demodulation without channel state information, which is attractive in fast fading channels where accurate channel estimates are difficult to obtain. More recently, a differential space-code modulation (DSCM) scheme, which is an improvement of DSTM for combating interference (including intentional and unintentional jamming) signals, was proposed. DSCM significantly outperforms DSTM when interference is present. This advantage, however, is achieved at the cost of a lower transmission rate, a wider bandwidth, or a combination of both. To alleviate this problem, we extend DSCM to a so-called high-rate DSCM (HR-DSCM) scheme, which increases the data rate considerably at the cost of a slightly higher bit error rate, while still maintaining the interference suppression capability.
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| 18. |
- Liu, Jianhua, et al.
(författare)
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In situ growth of perovskite stacking layers for high-efficiency carbon-based hole conductor free perovskite solar cells
- 2019
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry (RSC). - 2050-7488 .- 2050-7496. ; 7:22, s. 13777-13786
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Tidskriftsartikel (refereegranskat)abstract
- The interfacial properties between a perovskite layer and carbon electrode are critical for the photovoltaic performance of carbon electrode-based perovskite solar cells (PSCs). Herein, a methylammonium lead mixed halide (MAPbIxBr3−x) perovskite layer is in situ grown on the top of a methylammonium lead iodide (MAPbI3) perovskite layer forming a MAPbI3/MAPbIxBr3−x perovskite stacking structure (PSS) to improve the interfacial properties at the perovskite/carbon electrode interface. The charge carrier dynamics in both the perovskite and the PSC device induced by the MAPbIxBr3−x perovskite stacking layer are studied using extensive characterization. The charge interfacial recombination at the perovskite/carbon electrode interface is significantly diminished using the PSS within the PSC, resulting in largely improved charge extraction and therefore high photovoltaic performance. The PSS-based PSC shows a power conversion efficiency of up to 16.2% (increased by 43% compared with that of a conventional MAPbI3-based PSC), which is among the highest efficiencies of carbon electrode-based hole conductor free PSCs. Meanwhile, the PSS-based PSC also exhibits good stability under both continuous illumination and storage under dark conditions. This work may provide a new avenue to fine tune the interfacial properties of carbon electrode-based PSCs for further improving their photovoltaic performance.
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| 19. |
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| 20. |
- Liu, Jianhua, et al.
(författare)
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Metal nanowire networks : Recent advances and challenges for new generation photovoltaics
- 2019
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Ingår i: Materials Today Energy. - : ELSEVIER SCI LTD. - 2468-6069. ; 13, s. 152-185
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Forskningsöversikt (refereegranskat)abstract
- Transparent conducting electrodes which allow photons passing through and simultaneously transfers the charge carriers are critical for the construction of high-performance photovoltaic cells. Electrodes based on metal oxides, such as indium-doped tin oxide (ITO) or fluorine-doped tin oxide (FTO), may have limited application in new generation flexible solar cells, which employ solution-processed roll-to-roll or ink-printing techniques toward large-area-fabrication approach, due to their brittleness and poor mechanical properties. Metal nanowire network (MNWN) emerges as a highly potential alternative candidate instead of ITO or FTO due to the high transparency, low sheet resistance, low cost, solution processable and compatibility with a flexible substrate for high throughput production. This feature article systematically summarizes the recent advances of the MNWNs, including new concepts and emerging strategies for the synthesis of metal nanowires (MNWs), various approaches for the preparation of MNWNs and comprehensively discusses the novel MNWN electrodes prepared on different substrates. The state-of-the-art new generation solar cell devices, such as transparent, flexible and light-weight solar cells, with MNWN as a transparent conductive electrode are emphasized. Finally, the opportunities and challenges for the development of MNWN electrodes toward application in the new generations of photovoltaic devices are discussed.
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| 21. |
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| 22. |
- Liu, Xiangdong, et al.
(författare)
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Cancer risk in patients with hepatitis C virus infection : A population-based study in Sweden
- 2017
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Ingår i: Cancer Medicine. - : Wiley. - 2045-7634. ; 6:5, s. 1135-1140
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Tidskriftsartikel (refereegranskat)abstract
- Increased risks of certain cancers have been observed in patients with hepatitis C virus (HCV) infection. However, data on other cancer sites/types are lacking. We analyzed systematically the risk of developing 35 common cancers in patients with HCV infection using a nationwide Swedish database. Patients with HCV infection were identified from the Swedish Hospital Inpatient and Outpatient Register and Primary Health Care Database, and followed until the diagnosis of cancer. Standardized incidence ratios (SIRs) were calculated for subsequent 35 common cancer sites/types between 1990 and 2010 in patients with HCV infection in Sweden. Increased risks were recorded for six cancers. The highest SIR was seen for liver cancer (36.67; 95% CI: 33.20-40.40). The decreased risk was for prostate cancer (0.73; 95% CI: 0.59-0.90) and melanoma (0.50; 95% CI: 0.30-0.79). A significant sex-difference for cancer was observed only for liver cancer (40.72; 95% CI: 36.36-45.45 for men and 27.21; 95% CI: 21.90-33.41 for women). Also, increased SIRs were noted only for liver cancer during the entire period of follow-up. HCV infection was associated with an increased incidence of liver cancer and additionally five other types of cancer. Active surveillance of other cancers may be needed in order to be diagnosed at an earlier stage.
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| 23. |
- Liu, Yapeng, et al.
(författare)
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A Robust Direction of Arrival Estimation Method for Coherently Distributed Sources in an Impulsive Noise Environment
- 2023
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Ingår i: IEEE Sensors Journal. - 1530-437X. ; 23:13, s. 14375-14387
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Tidskriftsartikel (refereegranskat)abstract
- In this work, a computationally efficient evolutionary algorithm is proposed for estimating the direction of arrival (DOA) of coherently distributed (CD) sources corrupted by additive impulsive noise. The typical method, such as distributed signal parameter estimation (DSPE) method, requires a 2-D spectral peak search and cannot allow for coherent signals. The proposed method in this article uses an infinite norm (IN) normalization combined with the maximum likelihood (ML) criteria. The resulting cost function is solved using the introduced multimodal quantum-inspired benchmarking algorithm (MQBA), which obviously reduces the computational complexity without grid errors. The Cramer-Rao bound (CRB) for the considered DOA estimation problem is also derived. Finally, numerical simulations are conducted to show that our algorithm can perform superior robustness and allow for coherent signals without any additional process compared with alternative approaches for the considered scenarios. In addition, the proposed scheme can be popularized to address other DOA estimation problems and promote the development of DOA estimation.
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| 24. |
- Pfeiffer, Thomas, et al.
(författare)
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Predicting the replicability of social and behavioural science claims in a crisis: The COVID-19 Preprint Replication Project
- 2023
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Replications are important for assessing the reliability of published findings. However, they are costly, and it is infeasible to replicate everything. Accurate, fast, lower-cost alternatives such as eliciting predictions could accelerate assessment for rapid policy implementation in a crisis. We elicited judgments from participants on 100 claims from preprints about an emerging area of research (COVID-19 pandemic) using an interactive structured elicitation protocol, and we conducted 29 new high-powered replications. After interacting with their peers, participant groups with lower task expertise (‘beginners’) updated their estimates and confidence in their judgements significantly more than groups with greater task expertise (‘experienced’). For experienced individuals, the average accuracy was 0.57 (95% CI: [0.53, 0.61]) after interaction, and they correctly classified 61% of claims; beginners’ average accuracy was 0.58 (95% CI: [0.54, 0.62]), correctly classifying 69% of claims. The difference in accuracy between groups was not statistically significant, and their judgments on the full set of claims were correlated (r=.48). These results suggest that both beginners and more experienced participants using a structured process have some ability to make better-than-chance predictions about the reliability of ‘fast science’ under conditions of high uncertainty. However, given the importance of such assessments for making evidence-based critical decisions in a crisis, more research is required to understand who the right experts in forecasting replicability are and how their judgements ought to be elicited.
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| 25. |
- Shiwei, Tian, et al.
(författare)
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Effect of Mo Element on Microstructure and Mechanical Properties of TiAl Alloys
- 2022
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Ingår i: Xiyou jinshu cailiao yu gongcheng. - : NORTHWEST INST NONFERROUS METAL RESEARCH. - 1002-185X. ; 51:7, s. 2336-2343
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Tidskriftsartikel (refereegranskat)abstract
- Four TiAl alloys with different Mo contents were designed, and the microstructure and mechanical properties of these MoTiAl alloys were studied by scanning electron microscope, nanoindentation, and hot compression simulation methods. Results show that with increasing the Mo content, the content of. phase is gradually decreased, while that of beta phase is gradually increased. The Mo element mainly exists in the form of beta phase in the TiAl alloy. During the hot isostatic pressing process, the Mo element is diffused from the. and a 2 phases to the beta phase. The nanoindentation hardness of Mo-TiAl alloy reaches the maximum when the Mo content is 1.59at%, and it is negatively correlated with the interlamellar space. As the content of Mo element increases, the flow stress of Mo-TiAl alloys decreases, and the TiAl alloys with 2.11at% and 3.94at% Mo addtion have poor plasticity due to the Al element segregation.
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| 26. |
- Shiwei, Tian, et al.
(författare)
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Oxidation resistance of TiAl alloy improved by hot-pack rolling and cyclic heat treatment
- 2021
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Ingår i: Materials Characterization. - : Elsevier BV. - 1044-5803 .- 1873-4189. ; 178
-
Tidskriftsartikel (refereegranskat)abstract
- The isothermal oxidation behavior of two TiAl alloys (as-HIP and as-RHT) were compared to explain the effect of microstructure on the oxidation resistance of TiAl alloy. After hot-pack rolling and cyclic heat treatment, the size of lamellar colonies was refined from 35.4 mu m to 21.5 mu m, and the beta/B2 phase was effectively removed. It is concluded that the as-RHT TiAl alloy has better oxidation resistance than the as-HIP TiAl alloy. The main reason is due to refinement of lamellar colony size, elimination of beta/B2 phase, uniform distribution of Nb and Mo, and the crushing of Y compounds.
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| 27. |
- Sun, Huiliang, et al.
(författare)
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Reducing energy loss via tuning energy levels of polymer acceptors for efficient all-polymer solar cells
- 2020
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Ingår i: Science China Chemistry. - : Springer Science and Business Media LLC. - 1869-1870 .- 1674-7291. ; 63:12, s. 1785-1792
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Tidskriftsartikel (refereegranskat)abstract
- The open-circuit voltage (Voc) of all-polymer solar cells (all-PSCs) is typically lower than 0.9 V even for the most efficient ones. Large energy loss is the main reason for limiting Voc and efficiency of all-PSCs. Herein, through materials design using electron deficient building blocks based on bithiophene imides, the lowest unoccupied molecular orbital (LUMO) energy levels of polymer acceptors can be effectively tuned, which resulted in a reduced energy loss induced by charge generation and recombination loss due to the suppressed charge-transfer (CT) state absorption. Despite a negligible driving force, all-PSC based on the polymer donor and acceptor combination with well-aligned energy levels exhibited efficient charge transfer and achieved an external quantum efficiency over 10% while maintaining a large Voc of 1.02 V, leading to a 9.21% efficiency. Through various spectroscopy approaches, this work sheds light on the mechanism of energy loss in all-PSCs, which paves an avenue to achieving efficient all-PSCs with large Voc and drives the further development of all-PSCs.
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| 28. |
- Sun, Huiliang, et al.
(författare)
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Reducing energy lossviatuning energy levels of polymer acceptors for efficient all-polymer solar cells
- 2020
-
Ingår i: Science China Chemistry. - : Science China Press and Springer-Verlag GmbH Germany. - 1674-7291 .- 1869-1870. ; 63, s. 1785-1792
-
Tidskriftsartikel (refereegranskat)abstract
- The open-circuit voltage (V-oc) of all-polymer solar cells (all-PSCs) is typically lower than 0.9 V even for the most efficient ones. Large energy loss is the main reason for limitingV(oc)and efficiency of all-PSCs. Herein, through materials design using electron deficient building blocks based on bithiophene imides, the lowest unoccupied molecular orbital (LUMO) energy levels of polymer acceptors can be effectively tuned, which resulted in a reduced energy loss induced by charge generation and recombination loss due to the suppressed charge-transfer (CT) state absorption. Despite a negligible driving force, all-PSC based on the polymer donor and acceptor combination with well-aligned energy levels exhibited efficient charge transfer and achieved an external quantum efficiency over 10% while maintaining a largeV(oc)of 1.02 V, leading to a 9.21% efficiency. Through various spectroscopy approaches, this work sheds light on the mechanism of energy loss in all-PSCs, which paves an avenue to achieving efficient all-PSCs with largeV(oc)and drives the further development of all-PSCs.
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| 29. |
- Tian, Shiwei, et al.
(författare)
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Investigation on the microstructure evolution and dynamic recrystallization mechanisms of TiAl alloy at elevated temperature
- 2021
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Ingår i: Journal of Materials Research and Technology. - : Elsevier BV. - 2238-7854. ; 14, s. 968-984
-
Tidskriftsartikel (refereegranskat)abstract
- The flow stress–strain curves appear to be sensitive to deformation conditions. The ratio of critical strain to peak strain εc/εp follows a linear relationship except when the temperature is 1240 °C and the strain rate is 0.001 s−1. During the deformation, the fragmentation and decomposition of γ/α2 lamellae are related to recrystallization of α2 and γ laths in the lamellae and the γ → α2 phase transformation, the former depends on dislocation slip and twinning, and the latter is related to temperature, local stress concentration and diffusion time. As for the recrystallization mechanisms, the γ phase is discontinuous dynamic recrystallization (DDRX) mode, while the α2 phase relies on continuous dynamic recrystallization (CDRX) mode. The β phase has more low-angle grain boundaries (LAGB) during deformation, indicating the continuous coordinated deformation, and this explains the enlarged hot working window of the TiAl alloy (1165–1240 °C/0.001 ~ 1 s−1 and 1120–1165 °C/0.001–0.4 s−1).
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| 30. |
- Wang, Fang, et al.
(författare)
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Emerging contaminants: A One Health perspective
- 2024
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Ingår i: Innovation. - 2666-6758. ; 5
-
Forskningsöversikt (refereegranskat)abstract
- Environmental pollution is escalating due to rapid global development that often prioritizes human needs over planetary health. Despite global efforts to mitigate legacy pollutants, the continuous introduction of new substances remains a major threat to both people and the planet. In response, global initiatives are focusing on risk assessment and regulation of emerging contaminants, as demonstrated by the ongoing efforts to establish the UN's Intergovernmental Science-Policy Panel on Chemicals, Waste, and Pollution Prevention. This review identifies the sources and impacts of emerging contaminants on planetary health, emphasizing the importance of adopting a One Health approach. Strategies for monitoring and addressing these pollutants are discussed, underscoring the need for robust and socially equitable environmental policies at both regional and international levels. Urgent actions are needed to transition toward sustainable pollution management practices to safeguard our planet for future generations.
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| 31. |
- Xiong, Shaobing, et al.
(författare)
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Additive-Induced Synergies of Defect Passivation and Energetic Modification toward Highly Efficient Perovskite Solar Cells
- 2021
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Ingår i: Advanced Energy Materials. - : WILEY-V C H VERLAG GMBH. - 1614-6832 .- 1614-6840. ; 11:29
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Tidskriftsartikel (refereegranskat)abstract
- Defect passivation via additive and energetic modification via interface engineering are two effective strategies for achieving high-performance perovskite solar cells (PSCs). Here, the synergies of pentafluorophenyl acrylate when used as additive, in which it not only passivates surface defect states but also simultaneously modifies the energetics at the perovskite/Spiro-OMeTAD interface to promote charge transport, are shown. The additive-induced synergy effect significantly suppresses both defect-assisted recombination and interface carrier recombination, resulting in a device efficiency of 22.42% and an open-circuit voltage of 1.193 V with excellent device stability. The two photovoltaic parameters are among the highest values for polycrystalline CsFormamidinium/Methylammonium (FAMA)/FAMA based n-i-p structural PSCs using low-cost silver electrodes reported to date. The findings provide a promising approach by choosing the dual functional additive to enhance efficiency and stability of PSCs.
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| 32. |
- Xiong, Shaobing, et al.
(författare)
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Direct Observation on p- to n-Type Transformation of Perovskite Surface Region during Defect Passivation Driving High Photovoltaic Efficiency
- 2021
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Ingår i: Joule. - : CELL PRESS. - 2542-4351. ; 5:2, s. 467-480
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Tidskriftsartikel (refereegranskat)abstract
- Perovskite solar cells (PSCs) suffer from significant nonradiative recombination, limiting their power conversion efficiencies. Here, for the first time, we directly observe a complete transformation of perovskite MAPbI(3) surface region energetics from p- to n-type during defect passivation caused by natural additive capsaicin, attributed to the spontaneous formation of a p-n homojunction in perovskite active layer. We demonstrate that the p-n homojunction locates at similar to 100 nm below perovskite surface. The energetics transformation and defect passivation promote charge transport in bulk perovskite layer and at perovskite/PCBM interface, suppressing both defect-assisted recombination and interface carrier recombination. As a result, an efficiency of 21.88% and a fill factor of 83.81% with excellent device stability are achieved, both values are the highest records for polycrystalline MAPbI(3) based p-i-n PSCs reported to date. The proposed new concept of synergetic defect passivation and energetic modification via additive provides a huge potential for further improvement of PSC performance.
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| 33. |
- Xu, Han, et al.
(författare)
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Dissecting the structure-stability relationship of Y-series electron acceptors for real-world solar cell applications
- 2023
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Ingår i: Joule. - 2542-4351. ; 7:9, s. 2135-2151
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Tidskriftsartikel (refereegranskat)abstract
- Despite striking progress toward improving the photovoltaic (PV) performance of organic solar cells (OSCs) with recent Y-series non-fullerene acceptors (Y-NFAs), knowledge about their outdoor performance under real-world conditions and photodegradation mechanisms remains elusive, which is urgently needed to close the lab-to-fab gap of OSCs. Herein, for the first time, we study the structure-outdoor-stability relationship of Y-NFAs. We show that Y-NFAs with long internal side-chains exhibit high energy barriers for photoisomerization, and fluorinated end-groups can enhance the structural confinement to inhibit the photodegradation pathway and thereby improve device stability. Furthermore, the performance loss of Y-NFA-based OSCs under illumination is mainly driven by increased trap-assisted recombination over time. The structure-stability correlation and demonstration of outdoor performance of these state-of-the-art Y-NFA cells provided in this study highlight molecular engineering of device stability control to minimize power output losses in real-world climates.
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| 34. |
- Yang, Jianming, et al.
(författare)
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Comprehensive understanding of heat-induced degradation of triple-cation mixed halide perovskite for a robust solar cell
- 2018
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Ingår i: Nano Energy. - : ELSEVIER SCIENCE BV. - 2211-2855 .- 2211-3282. ; 54, s. 218-226
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Tidskriftsartikel (refereegranskat)abstract
- The triple-cation mixed halide perovskite Cs-0.05(MA(0.17)FA(0.83))(0.95)Pb(I0.83Br0.17)(3) emerges as one of the most promising candidates for photovoltaics due to superior optoelectronic properties, but the thermal stability is still a major challenge for the viability of perovskite solar cells towards commercialization. Herein, we firstly explore the thermal response of the photovoltaic performances to access device physical changes. It is shown that the efficiency loss originates from decreased charge mobility, increased trap density and generation of PbI2 charge recombination centers near the interface. In-depth analysis of evolutions in morphology, chemical composition, dynamic and electronic structure of the perovskite layer at the nanometer scales indicates that it is initial dangling bonds and vacancies on the imperfect surfaces decrease the activation energy and cause the perovskite decomposition in a layer-by-layer pathway sequentially from the film surface to bulk. Based on the results, a strategy of surface passivation to improve the thermal stability is demonstrated and discussed. This work for the first time provides insights into the physical and chemical change of such triple-cation perovskite and indicates that more effort should be invested in surface treatment for enhancing perovskite device stability.
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| 35. |
- Yang, Jianming, et al.
(författare)
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Extremely Low-Cost and Green Cellulose Passivating Perovskites for Stable and High-Performance Solar Cells
- 2019
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 11:14, s. 13491-13498
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Tidskriftsartikel (refereegranskat)abstract
- The fast evolution of metal halide perovskite solar cells has opened a new chapter in the field of renewable energy. High-quality perovskite films as the active layers are essential for both high efficiency and long-term stability. Here, the perovskite films with enlarged crystal grain size and decreased defect density are fabricated by introducing the extremely low-cost and green polymer, ethyl cellulose (EC), into the perovskite layer. The addition of EC triggers hydrogen bonding interactions between EC and the perovskite, passivating the charge defect traps at the grain boundaries. The long chain of EC further acts as a scaffold for the perovskite structure, eliminating the annealing-induced lattice strain during the film fabrication process. The resulting devices with the EC additive exhibit a remarkably enhanced average power conversion efficiency from 17.11 to 19.27% and an improvement of all device parameters. The hysteresis index is found to decrease by three times from 0.081 to 0.027, which is attributed to suppressed ion migration and surface charge trapping. In addition, the defect passivation by EC significantly improves the environmental stability of the perovskite films, yielding devices that retain 80% of their initial efficiency after 30 days in ambient air at 45% relative humidity, whereas the pristine devices without EC fully degrade. This work provides a low-cost and green avenue for passivating defects that improves both the efficiency and operational stability of perovskite solar cells.
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| 36. |
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| 37. |
- Yao, Yao, et al.
(författare)
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Flexible and Stretchable Organic Electrochemical Transistors for Physiological Sensing Devices
- 2023
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Ingår i: Advanced Materials. - : WILEY-V C H VERLAG GMBH. - 0935-9648 .- 1521-4095. ; 35:35
-
Forskningsöversikt (refereegranskat)abstract
- Flexible and stretchable bioelectronics provides a biocompatible interface between electronics and biological systems and has received tremendous attention for in situ monitoring of various biological systems. Considerable progress in organic electronics has made organic semiconductors, as well as other organic electronic materials, ideal candidates for developing wearable, implantable, and biocompatible electronic circuits due to their potential mechanical compliance and biocompatibility. Organic electrochemical transistors (OECTs), as an emerging class of organic electronic building blocks, exhibit significant advantages in biological sensing due to the ionic nature at the basis of the switching behavior, low driving voltage (<1 V), and high transconductance (in millisiemens range). During the past few years, significant progress in constructing flexible/stretchable OECTs (FSOECTs) for both biochemical and bioelectrical sensors has been reported. In this regard, to summarize major research accomplishments in this emerging field, this review first discusses structure and critical features of FSOECTs, including working principles, materials, and architectural engineering. Next, a wide spectrum of relevant physiological sensing applications, where FSOECTs are the key components, are summarized. Last, major challenges and opportunities for further advancing FSOECT physiological sensors are discussed.
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| 38. |
- Zhang, Xiaoliang, et al.
(författare)
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Efficient charge-carrier extraction from Ag2Squantum dots prepared by the SILAR method for utilization of multiple exciton generation
- 2015
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Ingår i: Nanoscale. - 2040-3364 .- 2040-3372. ; 7:4, s. 1454-1462
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Tidskriftsartikel (refereegranskat)abstract
- The utilization of electron–hole pairs (EHPs) generated from multiple excitons in quantum dots (QDs) is of great interest toward efficient photovoltaic devices and other optoelectronic devices; however, extraction of charge carriers remains difficult. Herein, we extract photocharges from Ag2S QDs and investigate the dependence of the electric field on the extraction of charges from multiple exciton generation (MEG). Low toxic Ag2S QDs are directly grown on TiO2 mesoporous substrates by employing the successive ionic layer adsorption and reaction (SILAR) method. The contact between QDs is important for the initial charge separation after MEG and for the carrier transport, and the space between neighbor QDs decreases with more SILAR cycles, resulting in better charge extraction. At the optimal electric field for extraction of photocharges, the results suggest that the threshold energy (hνth) for MEG is 2.41Eg. The results reveal that Ag2S QD is a promising material for efficient extraction of charges from MEG and that QDs prepared by SILAR have an advantageous electrical contact facilitating charge separation and extraction.
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| 39. |
- Zhang, Xiaoliang, et al.
(författare)
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Enhanced charge carrier extraction by a highly ordered wrinkled MgZnO thin film for colloidal quantum dot solar cells
- 2017
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Ingår i: Journal of Materials Chemistry C. - 2050-7526 .- 2050-7534. ; 5:42, s. 11111-11120
-
Tidskriftsartikel (refereegranskat)abstract
- Efficient charge carrier extraction from a colloidal quantum dot (CQD) solid is crucial for highperformance of CQD solar cells (CQDSCs). Herein, highly ordered wrinkled MgZnO (MZO) thin films aredemonstrated to improve the charge carrier extraction of PbS CQDSCs. The highly ordered wrinkledMZO thin films are prepared using a low-temperature combustion method. The photovoltaicperformances of CQDSCs with a combustion-processed MZO (CP-MZO) thin film as an electrontransport material (ETM) are compared to those of CQDSCs with a conventional sol–gel processed MZO(SGP-MZO) thin film as an ETM. We performed photoluminescence quenching measurements of thecolloidal quantum dot (CQD) solid and charge carrier dynamic analysis of full solar cell devices. Theresults show that the highly ordered wrinkled CP-MZO thin film significantly increases the chargecarrier extraction from the CQD solid and therefore diminishes the charge interfacial recombination atthe CQD/ETM junction, leading to a 15.5% increase in power conversion efficiency. The improvedefficiency in the CP-MZO based CQDSC is also attributed to the compact and pin-hole free CP-MZOthin film.
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| 40. |
- Zhang, Xiaoliang, et al.
(författare)
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FTO-free top-illuminated colloidal quantum dot electro-optics in devices
- 2017
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Ingår i: Solar Energy. - : Elsevier BV. - 0038-092X .- 1471-1257. ; 158, s. 533-542
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Tidskriftsartikel (refereegranskat)abstract
- A solar cell device architecture with top-illumination, where the light does not pass through the substrate, is advantageous for many applications. It is also specifically useful for the construction of tandem or multiple junction photovoltaic devices, with illumination through the top solar cell. Here, a top-illuminated colloidal quantum dot solar cell (TI-CQDSC) is demonstrated and compared with a conventional colloidal quantum dot solar cell (C-CQDSC) constructed on a FTO (fluorine doped tin oxide) glass substrate both theoretically and experimentally. The optical electric field distribution in the solar cells with different configuration is simulated using transfer matrix formalism and a more intense optical electric field was observed in TI-CQDSC, leading to a higher exciton generation rate within the colloidal quantum dot solid. The TI-CQDSCs are constructed on both nonconductive glass and flexible substrates, and a maximum power conversion efficiency of 6.4% and 5.6% is achieved, respectively, comparing to that of 5.9% for the C-CQDSC. The improved performance of the top illuminated solar cell is attributed to a combination of enhanced optical electric field intensity in the colloidal quantum dot solid and superior conductivity of the transparent metal film electrode.
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| 41. |
- Zhang, Xiaoliang, et al.
(författare)
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Highly photostable and efficient semitransparent quantum dot solar cells by using solution-phase ligand exchange
- 2018
-
Ingår i: Nano Energy. - : Elsevier BV. - 2211-2855 .- 2211-3282. ; 53, s. 373-382
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Tidskriftsartikel (refereegranskat)abstract
- For semitransparent solar cells (SSCs) the photovoltaic efficiency and the transparency are the two primary objectives for utilization in for example building integrated photovoltaics. Solution-processed PbS colloidal quantum dot (CQD) has strong light absorption in the ultraviolent region and possess the advantages of tunable bandgap in the visible and infrared region. Herein we report a PbS CQD-SSC with tunable infrared light absorption and high photostability by combining experimental studies and numerical theoretical simulations. Through fine-controlling the electro-optics in the CQD-SSC and by using a solution-phase ligand exchange for the CQD solid film deposition, the power loss in the device is significantly decreased, yielding a CQD-SSC with a power conversion efficiency of 8.4% and an average visible transmittance of 21.4%, respectively. After 540 h continuous 100 mW cm(-2) illumination the solar cell still shows similar to 85% of its initial power conversion efficiency, and then recovers to the initial performance after storage in dark. This work provides a strong progress and an approach toward the development of low-cost, highly efficient and stable semitransparent CQD solar cells. Meanwhile this study also provides insight and quantitative guidelines for further improving the SSC photovoltaic efficiency and transparency in general.
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| 42. |
- Zhang, Xiaoliang, et al.
(författare)
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Inorganic CsPbI3 Perovskite Coating on PbS Quantum Dot for Highly Efficient and Stable Infrared Light Converting Solar Cells
- 2018
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Ingår i: Advanced Energy Materials. - : Wiley-VCH Verlagsgesellschaft. - 1614-6832 .- 1614-6840. ; 8:6
-
Tidskriftsartikel (refereegranskat)abstract
- Solution-processed colloidal quantum dot (CQD) solar cells harvesting the infrared part of the solar spectrum are especially interesting for future use in semitransparent windows or multilayer solar cells. To improve the device power conversion efficiency (PCE) and stability of the solar cells, surface passivation of the quantum dots is vital in the research of CQD solar cells. Herein, inorganic CsPbI3 perovskite (CsPbI3-P) coating on PbS CQDs with a low-temperature, solution-processed approach is reported. The PbS CQD solar cell with CsPbI3-P coating gives a high PCE of 10.5% and exhibits remarkable stability both under long-term constant illumination and storage under ambient conditions. Detailed characterization and analysis reveal improved passivation of the PbS CQDs with the CsPbI3-P coating, and the results suggest that the lattice coherence between CsPbI3-P and PbS results in epitaxial induced growth of the CsPbI3-P coating. The improved passivation significantly diminishes the sub-bandgap trap-state assisted recombination, leading to improved charge collection and therefore higher photovoltaic performance. This work therefore provides important insight to improve the CQD passivation by coating with an inorganic perovskite ligand for photovoltaics or other optoelectronic applications.
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| 43. |
- Zhang, Xiaoliang, et al.
(författare)
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Probing and Controlling Surface Passivation of PbS Quantum Dot Solid for Improved Performance of Infrared Absorbing Solar Cells
- 2019
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Ingår i: Chemistry of Materials. - : AMER CHEMICAL SOC. - 0897-4756 .- 1520-5002. ; 31:11, s. 4081-4091
-
Tidskriftsartikel (refereegranskat)abstract
- Surface properties of colloidal quantum dots (CQDs) are critical for the transportation and recombination of the photoinduced charge carrier in CQD solar cells, therefore dominating the photovoltaic performance. Herein, PbS CQD passivated using liquid-state ligand exchange (LSLX) and solid-state ligand exchange (SSLX) strategies are in detail investigated using photoelectron spectroscopy (PES), and solar cell devices are prepared to understand the link between the CQD surface properties and the solar cell function. PES using different energies in the soft and hard Xray regime is applied to study the surface and bulk properties of the CQDs, and the results show more effective surface passivation of the CQDs prepared with the LSLX strategy and less formation of lead-oxide. The CQD solar cells prepared with LSLX strategy show higher performance, and the photoelectric measurements suggest that the recombination of photoinduced charges is reduced for the solar cell prepared with the LSLX approach. Meanwhile, the fabricated solar cells exhibit good stability. This work provides important insights into how to fine-tune the CQD surface properties by improving the CQD passivation, and how this is linked to further improvements of the device photovoltaic performance.
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| 44. |
- Zhang, Xiaoliang, et al.
(författare)
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Slow recombination in quantum dot solid solar cellusing p–i–n architecture with organic p-type holetransport material
- 2015
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry (RSC). - 2050-7488 .- 2050-7496. ; 3:41, s. 20579-20585
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Tidskriftsartikel (refereegranskat)abstract
- The interfaces between different materials in the heterojunction colloidal quantum dot (QD) solar cell playan important role for charge carrier separation, recombination and collection. Here, an organic–inorganichybrid p–i–n architecture for the heterojunction PbS QD solid solar cell is constructed to increase thecharge extraction and reduce charge recombination. Heavily doped poly(3-hexylthiophene-2,5-diyl)(P3HT) is applied as hole transport interlayer between the QD film and metal contact electrode. Theresults show that the P3HT interlayer diminishes the charge carrier recombination at the QD film/metalcontact electrode interface leading to increased open-circuit voltage and increased electron life time.Furthermore, after incorporation of P3HT interlayer an additional p–i heterojunction might form atP3HT/QD film interface resulting in increased depletion region, which promotes charge carrierextraction under working conditions. Two other organic p-type interlayers are also investigated,however, the results indicate that a barrier for charge extraction is formed for these devices, which isexplained by the difference in energy levels. The solar cell with the P3HT interlayer exhibits a powerconversion efficiency of 5.1% at 1 sun of illumination and ambient atmosphere, which is 20% highercompared to the solar cell without any hole transport interlayer.
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| 45. |
- Zhang, Xiaoliang, et al.
(författare)
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Solution processed flexible and bending durable heterojunction colloidal quantum dot solar cell
- 2015
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Ingår i: Nanoscale. - : Royal Society of Chemistry (RSC). - 2040-3364 .- 2040-3372. ; 7:27, s. 11520-11524
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Tidskriftsartikel (refereegranskat)abstract
- A flexible hybrid heterojunction PbS colloidal quantum dot solar cell, where the photoactive layers are deposited using a solution processed fabrication approach under ambient condition and at room temperature is presented. The bending stability of the obtained solar cell is evaluated. The results show that the solar cell exhibits high bending stability and even under the bent state the cell also maintains a high performance, which shows the potential of the quantum dot solar cell toward a lightweight, bendable power source with many possible applications.
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| 46. |
- Zhang, Xiaoliang, et al.
(författare)
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ZnO@Ag2S core-shell nanowire arrays for environmentally friendly solid-state quantum dot-sensitized solar cells with panchromatic light capture and enhanced electron collection
- 2015
-
Ingår i: Physical Chemistry, Chemical Physics - PCCP. - : Royal Society of Chemistry (RSC). - 1463-9076 .- 1463-9084. ; 17:19, s. 12786-12795
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Tidskriftsartikel (refereegranskat)abstract
- A solid-state environmentally friendly Ag2S quantum dot-sensitized solar cell (QDSSC) is demonstrated. The photovoltaic device is fabricated by applying ZnO@Ag2S core-shell nanowire arrays (NWAs) as light absorbers and electron conductors, and poly-3-hexylthiophene (P3HT) as a solid-state hole conductor. Ag2S quantum dots (QDs) were directly grown on the ZnO nanowires by the successive ionic layer adsorption and reaction (SILAR) method to obtain the core-shell nanostructure. The number of SILAR cycles for QD formation and the length of the core-shell NWs significantly affect the photocurrent. The device with a core-shell NWAs photoanode shows a power conversion efficiency increase by 32% compared with the device based on a typical nanoparticle-based photoanode with Ag2S QDs. The enhanced performance is attributed to enhanced collection of the photogenerated electrons utilizing the ZnO nanowire as an efficient pathway for transporting the photogenerated electrons from the QD to the contact.
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