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  • 1.
    Dev, Apurba
    et al.
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Dev Choudhury, Bikash
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Abedin, Ahmad
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Anand, Srinivasan
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Fabrication of Periodic Nanostructure Assemblies by Interfacial Energy Driven Colloidal Lithography2014In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 24, no 29, p. 4577-4583Article in journal (Refereed)
    Abstract [en]

    A novel interfacial energy driven colloidal lithography technique to fabricate periodic patterns from solution-phase is presented and the feasibility and versatility of the technique is demonstrated by fabricating periodically arranged ZnO nanowire ensembles on Si substrates. The pattern fabrication method exploits different interfaces formed by sol-gel derived ZnO seed solution on a hydrophobic Si surface covered by a monolayer of colloidal silica spheres. While the hydrophobic Si surface prevents wetting by the seed solution, the wedge shaped regions surrounding the contact point between the colloidal particles and the Si substrate trap the solution due to interfacial forces. This technique allows fabrication of uniform 2D micropatterns of ZnO seed particles on the Si substrate. A hydrothermal technique is then used to grow well-defined periodic assemblies of ZnO nanowires. Tunability is demonstrated in the dimensions of the patterns by using silica spheres with different diameters. The experimental data show that the periodic ZnO nanowire assembly suppresses the total reflectivity of bare Si by more than a factor of 2 in the wavelength range 400-1300 nm. Finite-difference time-domain simulations of the wavelength-dependent reflectivity show good qualitative agreement with the experiments. The demonstrated method is also applicable for other materials synthesized by solution chemistry.

  • 2. Fang, Yeyu
    et al.
    Dumas, R. K.
    Nguyen Thi Ngooc, Ahn
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Material Physics, MF.
    Mohseni, Seyed Majid
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Material Physics, MF.
    Chung, Sunjae
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Material Physics, MF.
    Miller, C. W.
    Åkerman, Johan
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Material Physics, MF.
    A Nonvolatile Spintronic Memory Element with a Continuum of Resistance States2013In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 23, no 15, p. 1919-1922Article in journal (Refereed)
    Abstract [en]

    A continuum of stable remanent resistance states is reported in perpendicularly magnetized pseudo spin valves with a graded anisotropy free layer. The resistance states can be systematically set by an externally applied magnetic field. The gradual reversal of the free layer with applied field and the field-independent fixed layer leads to a range of stable and reproducible remanent resistance values, as determined by the giant magnetoresistance of the device. An analysis of first-order reversal curves combined with magnetic force microscopy shows that the origin of the effect is the field-dependent population of up and down domains in the free layer.

  • 3.
    Fischer, Andreas C.
    et al.
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Belova, Lyubov M.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Engineering Material Physics.
    Malm, Gunnar B.
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Kolahdouz, Mohammadreza
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Radamson, Henry
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Gylfason, Kristinn B.
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Niklaus, Frank
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    3D Free-Form Patterning of Silicon by Ion Implantation, Silicon Deposition, and Selective Silicon Etching2012In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 22, no 19, p. 4004-4008Article in journal (Refereed)
    Abstract [en]

    A method for additive layer-by-layer fabrication of arbitrarily shaped 3D silicon micro- and nanostructures is reported. The fabrication is based on alternating steps of chemical vapor deposition of silicon and local implantation of gallium ions by focused ion beam (FIB) writing. In a final step, the defined 3D structures are formed by etching the silicon in potassium hydroxide (KOH), in which the local ion implantation provides the etching selectivity. The method is demonstrated by fabricating 3D structures made of two and three silicon layers, including suspended beams that are 40 nm thick, 500 nm wide, and 4 μm long, and patterned lines that are 33 nm wide.

  • 4.
    Granskog, Viktor
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Andren, Oliver C. J.
    Cai, Yanling
    Gonzalez-Granillo, Marcela
    Fellander-Tsai, Li
    von Holst, Hans
    KTH, School of Technology and Health (STH), Health Systems Engineering, Ergonomics.
    Haldosen, Lars-Arne
    Malkoch, Michael
    Linear Dendritic Block Copolymers as Promising Biomaterials for the Manufacturing of Soft Tissue Adhesive Patches Using Visible Light Initiated Thiol-Ene Coupling Chemistry2015In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 25, no 42, p. 6596-6605Article in journal (Refereed)
    Abstract [en]

    A library of dendritic-linear-dendritic (DLD) materials comprising linear poly(ethylene glycol) and hyperbranched dendritic blocks based on 2,2-bis(hydroxymethyl) propionic acid is successfully synthesized and post-functionalized with peripheral allyl groups. Reactive DLDs with pseudo-generations of 3 to 6 (G3-G6) are isolated in large scale allowing their thorough evaluation as important components for the development of biomedical adhesives. Due to their branched nature and inherent degradable ester-bonds, promising biomaterial resins are accomplished with suitable viscosity, eliminating the excessive use of co-solvents. By utilizing benign high-energy visible light initiated thiol-ene coupling chemistry, DLDs together with tris[2-(3-mercaptopropionyloxy) ethyl] isocyanurate and surgical mesh enable the fabrication of soft tissue adhesive patches (STAPs) within a total irradiation time of 30 s. The STAPs display the ability to create good adhesion to wet soft tissue and encouraging results in cytotoxicity tests. All crosslinked materials are also found to degrade after being stored in human blood plasma and phosphate buffered saline. The proposed benign methodology coupled with the promising features of the crosslinked materials is herein envisioned as a soft tissue adhesive with properties that do not exist in currently available tissue adhesives.

  • 5.
    Granskog, Viktor
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Coating Technology.
    García-Gallego, Sandra
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Coating Technology.
    von Kieseritzky, Johanna
    Department of Clinical Science and Education and the Department of Hand Surgery, Karolinska Institutet.
    Rosendahl, Jennifer
    RISE Research Institutes of Sweden, Bioscience and Materials–Medical Device Technology.
    Stenlund, Patrik
    RISE Research Institutes of Sweden, Bioscience and Materials–Medical Device Technology.
    Zhang, Yuning
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Coating Technology.
    Petronis, Sarunas
    RISE Research Institutes of Sweden, Bioscience and Materials–Medical Device Technology.
    Lyvén, Benny
    RISE Research Institutes of Sweden, Bioscience and Materials–Medical Device Technology.
    Arner, Marianne
    Department of Clinical Science and Education and the Department of Hand Surgery, Karolinska Institutet.
    Håkansson, Joakim
    RISE Research Institutes of Sweden, Bioscience and Materials–Medical Device Technology.
    Malkoch, Michael
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Coating Technology.
    High-Performance Thiol–Ene Composites Unveil a New Era of Adhesives Suited for Bone Repair2018In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 28, no 26, article id 1800372Article in journal (Refereed)
    Abstract [en]

    The use of adhesives for fracture fixation can revolutionize the surgical procedures toward more personalized bone repairs. However, there are still no commercially available adhesive solutions mainly due to the lack of biocompatibility, poor adhesive strength, or inadequate fixation protocols. Here, a surgically realizable adhesive system capitalizing on visible light thiol–ene coupling chemistry is presented. The adhesives are carefully designed and formulated from a novel class of chemical constituents influenced by dental resin composites and self-etch primers. Validation of the adhesive strengthis conducted on wet bone substrates and accomplished via fiber-reinforced adhesive patch (FRAP) methodology. The results unravel, for the first time, on the promise of a thiol–ene adhesive with an unprecedented shear bondstrength of 9.0 MPa and that surpasses, by 55%, the commercially available acrylate dental adhesive system Clearfil SE Bond of 5.8 MPa. Preclinical validation of FRAPs on rat femur fracture models details good adhesion to the bone throughout the healing process, and are found biocompatible not giving rise to any inflammatory response. Remarkably, the FRAPs are found to withstand loads up to 70 N for 1000 cycles on porcine metacarpal fractures outperforming clinically used K-wires and match metal plates and screw implants.

  • 6. He, Yuhui
    et al.
    Scheicher, Ralph H.
    Grigoriev, Anton
    Ahuja, Rajeev
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Long, Shibing
    Huo, ZongLiang
    Liu, Ming
    Enhanced DNA Sequencing Performance Through Edge-Hydrogenation of Graphene Electrodes2011In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 21, no 14, p. 2674-2679Article in journal (Refereed)
    Abstract [en]

    The use of graphene electrodes with hydrogenated edges for solid-state nanopore-based DNA sequencing is proposed, and molecular dynamics simulations in conjunction with electronic transport calculations are performed to explore the potential merits of this idea. The results of the investigation show that, compared to the unhydrogenated system, edge-hydrogenated graphene electrodes facilitate the temporary formation of H-bonds with suitable atomic sites in the translocating DNA molecule. As a consequence, the average conductivity is drastically raised by about 3 orders of magnitude while exhibiting significantly reduced statistical variance. Furthermore, the effect of the distance between opposing electrodes is investigated and two regimes identified: for narrow electrode separation, the mere hindrance due to the presence of protruding hydrogen atoms in the nanopore is deemed more important, while for wider electrode separation, the formation of H-bonds becomes the dominant effect. Based on these findings, it is concluded that hydrogenation of graphene electrode edges represents a promising approach to reduce the translocation speed of DNA through the nanopore and substantially improve the accuracy of the measurement process for whole-genome sequencing.

  • 7.
    Horak, Josef
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science, Protein Engineering.
    Jansson, Ronnie
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science, Protein Engineering.
    Dev, Apurba
    Uppsala Univ, Ångström Lab, Solid State Elect, Uppsala Box 534, SE-75121 Uppsala, Sweden..
    Nilebäck, Linnea
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science, Protein Engineering.
    Behnam, Kiarash
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science, Protein Engineering.
    Linnros, Jan
    KTH, School of Engineering Sciences (SCI), Applied Physics, Photonics.
    Hedhammar, My
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science, Protein Engineering.
    Eriksson Karlström, Amelie
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science, Protein Engineering.
    Recombinant Spider Silk as Mediator for One-Step, Chemical-Free Surface Biofunctionalization2018In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 28, no 21, article id 1800206Article in journal (Refereed)
    Abstract [en]

    A unique strategy for effective, versatile, and facile surface biofunctionalization employing a recombinant spider silk protein genetically functionalized with the antibody-binding Z domain (Z-4RepCT) is reported. It is demonstrated that Z-silk can be applied to a variety of materials and platform designs as a truly one-step and chemical-free surface modification that site specifically captures antibodies while simultaneously reducing nonspecific adsorption. As a model surface, SiO2 is used to optimize and characterize Z-silk performance compared to the Z domain immobilized by a standard silanization method. First, Z-silk adsorption is investigated and verified its biofunctionality in a long-term stability experiment. To assess the binding capacity and protein-protein interaction stability of Z-silk, the coating is used to capture human antibodies in various assay formats. An eightfold higher binding capacity and 40-fold lower detection limit are obtained in the immunofluorescence assay, and the complex stability of captured antibodies is shown to be improved by a factor of 20. Applicability of Z-silk to functionalize microfluidic devices is demonstrated by antibody detection in an electrokinetic microcapillary biosensor. To test Z-silk for biomarker applications, real-time detection and quantification of human immunoglobulin G are performed in a plasma sample and C1q capture from human serum using an anti-C1q antibody.

  • 8.
    Hou, Jungang
    et al.
    DUT, Inst Energy Sci & Technol, DUT KTH Joint Educ & Res Ctr Mol Devices, State Key Lab Fine Chem, Dalian 116024, Peoples R China..
    Sun, Yiqing
    DUT, Inst Energy Sci & Technol, DUT KTH Joint Educ & Res Ctr Mol Devices, State Key Lab Fine Chem, Dalian 116024, Peoples R China..
    Li, Zhuwei
    DUT, Inst Energy Sci & Technol, DUT KTH Joint Educ & Res Ctr Mol Devices, State Key Lab Fine Chem, Dalian 116024, Peoples R China..
    Zhang, Bo
    DUT, Inst Energy Sci & Technol, DUT KTH Joint Educ & Res Ctr Mol Devices, State Key Lab Fine Chem, Dalian 116024, Peoples R China..
    Cao, Shuyan
    DUT, Inst Energy Sci & Technol, DUT KTH Joint Educ & Res Ctr Mol Devices, State Key Lab Fine Chem, Dalian 116024, Peoples R China..
    Wu, Yunzhen
    DUT, Inst Energy Sci & Technol, DUT KTH Joint Educ & Res Ctr Mol Devices, State Key Lab Fine Chem, Dalian 116024, Peoples R China..
    Gao, Zhanming
    DUT, Inst Energy Sci & Technol, DUT KTH Joint Educ & Res Ctr Mol Devices, State Key Lab Fine Chem, Dalian 116024, Peoples R China..
    Sun, Licheng
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry. DUT, Inst Energy Sci & Technol, DUT KTH Joint Educ & Res Ctr Mol Devices, State Key Lab Fine Chem, Dalian 116024, Peoples R China.
    Electrical Behavior and Electron Transfer Modulation of Nickel-Copper Nanoalloys Confined in Nickel-Copper Nitrides Nanowires Array Encapsulated in Nitrogen-Doped Carbon Framework as Robust Bifunctional Electrocatalyst for Overall Water Splitting2018In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 28, no 37, article id 1803278Article in journal (Refereed)
    Abstract [en]

    Probing robust electrocatalysts for overall water splitting is vital in energy conversion. However, the catalytic efficiency of reported catalysts is still limited by few active sites, low conductivity, and/or discrete electron transport. Herein, bimetallic nickel-copper (NiCu) nanoalloys confined in mesoporous nickel-copper nitride (NiCuN) nanowires array encapsulated in nitrogen-doped carbon (NC) framework (NC-NiCu-NiCuN) is constructed by carbonization-/nitridation-induced in situ growth strategies. The in situ coupling of NiCu nanoalloys, NiCuN, and carbon layers through dual modulation of electrical behavior and electron transfer is not only beneficial to continuous electron transfer throughout the whole system, but also promotes the enhancement of electrical conductivity and the accessibility of active sites. Owing to strong synergetic coupling effect, such NC-NiCu-NiCuN electrocatalyst exhibits the best hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performance with a current density of 10 mA cm(-2) at low overpotentials of 93 mV for HER and 232 mV for OER, respectively. As expected, a two-electrode cell using NC-NiCu-NiCuN is constructed to deliver 10 mA cm(-2) water-splitting current at low cell voltage of 1.56 V with remarkable durability over 50 h. This work serves as a promising platform to explore the design and synthesis of robust bifunctional electrocatalyst for overall water splitting.

  • 9. Hou, Jungang
    et al.
    Sun, Yiqing
    Wu, Yunzhen
    Cao, Shuyan
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Promoting Active Sites in Core-Shell Nanowire Array as Mott-Schottky Electrocatalysts for Efficient and Stable Overall Water Splitting2018In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 28, no 4, article id 1704447Article in journal (Refereed)
    Abstract [en]

    Developing earth-abundant, active, and robust electrocatalysts for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) remains a vital challenge for efficient conversion of sustainable energy sources. Herein, metal-semiconductor hybrids are reported with metallic nanoalloys on various defective oxide nanowire arrays (Cu/CuOx, Co/CoOx, and CuCo/CuCoOx) as typical Mott-Schottky electrocatalysts. To build the highway of continuous electron transport between metals and semiconductors, nitrogen-doped carbon (NC) has been implanted on metal-semiconductor nanowire array as core-shell conductive architecture. As expected, NC/CuCo/CuCoOx nanowires arrays, as integrated Mott-Schottky electrocatalysts, present an overpotential of 112 mV at 10 mA cm(-2) and a low Tafel slope of 55 mV dec(-1) for HER, simultaneously delivering an overpotential of 190 mV at 10 mA cm(-2) for OER. Most importantly, NC/CuCo/CuCoOx architectures, as both the anode and the cathode for overall water splitting, exhibit a current density of 10 mA cm(-2) at a cell voltage of 1.53 V with excellent stability due to high conductivity, large active surface area, abundant active sites, and the continuous electron transport from prominent synergetic effect among metal, semiconductor, and nitrogen-doped carbon. This work represents an avenue to design and develop efficient and stable Mott-Schottky bifunctional electrocatalysts for promising energy conversion.

  • 10. Jansson, Ronnie
    et al.
    Courtin, Christophe M.
    Sandgren, Mats
    Hedhammar, My
    KTH, School of Biotechnology (BIO), Protein Technology. Swedish University of Agricultural Sciences, Sweden.
    Rational Design of Spider Silk Materials Genetically Fused with an Enzyme2015In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 25, no 33, p. 5343-5352Article in journal (Refereed)
    Abstract [en]

    Enzyme immobilization is an attractive route for achieving catalytically functional surfaces suitable for both continuous and repeated use. Herein, genetic engineering is used to combine the catalytic ability of a xylanase with the self-assembly properties of recombinant spider silk, realizing silk materials with enzymatic activity. Under near-physiological conditions, soluble xylanase-silk fusion proteins assembled into fibers displaying catalytic activity. Also, a xylanase-silk protein variant with the silk part miniaturized to contain only the C-terminal domain of the silk protein formed fibers with catalytic activity. The repertoire of xylanase-silk formats is further extended to include 2D surface coatings and 3D foams, also being catalytically active, showing the versatile range of possible silk materials. The stability of the xylanase-silk materials is explored, demonstrating the possibility of storage, reuse, and cleaning with ethanol. Interestingly, fibers can also be stored dried with substantial residual activity after rehydration. Moreover, a continuous enzymatic reaction using xylanase-silk is demonstrated, making enzymatic batch reactions not the sole possible implementation. The proof-of-concept for recombinantly produced enzyme-silk, herein shown with a xylanase, implies that also other enzymes can be used in similar setups. It is envisioned that the concept of enzyme-silk can find its applicability in, for example, multienzyme reaction systems or biosensors.

  • 11.
    Jiang, Xiao
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Karlsson, Karl Martin
    KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD. KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Gabrielsson, Erik
    KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD. KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Johansson, Erik M. J.
    KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Quintana, Maria
    KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Karlsson, Martin
    KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD. KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Boschloo, Gerrit
    KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Hagfeldt, Anders
    KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Highly Efficient Solid-State Dye-Sensitized Solar Cells Based on Triphenylamine Dyes2011In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 21, no 15, p. 2944-2952Article in journal (Refereed)
    Abstract [en]

    Two triphenylamine-based metal-free organic sensitizers, D35 with a single anchor group and M14 with two anchor groups, have been applied in dye-sensitized solar cells (DSCs) with a solid hole transporting material or liquid iodide/triiodide based electrolyte. Using the molecular hole conductor 2,2',7,7'-tetrakis-(N,N-di-p-methoxyphenyl-amine)9,9'-spirobifluorene (spiro-OMeTAD), good overall conversion efficiencies of 4.5% for D35 and 4.4% for M14 were obtained under standard AM 1.5G illumination (100 mW cm(-2)). Although M14 has a higher molar extinction coefficient (by similar to 60%) and a slightly broader absorption spectrum compared to D35, the latter performs slightly better due to longer lifetime of electrons in the TiO(2), which can be attributed to differences in the molecular structure. In iodide/triiodide electrolyte-based DSCs, D35 outperforms M14 to a much greater extent, due to a very large increase in electron lifetime. This can be explained by both the greater blocking capability of the D35 monolayer and the smaller degree of interaction of triiodide (iodine) with D35 compared to M14. The present work gives some insight into how the molecular structure of sensitizer affects the performance in solid-state and iodide/triiodide-based DSCs.

  • 12.
    Jiang, Xue
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Zhao, J.
    Li, Y. -L
    Ahuja, Rajeev
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Tunable assembly of sp3 cross-linked 3D graphene monoliths: A first-principles prediction2013In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 23, no 47, p. 5846-5853Article in journal (Refereed)
    Abstract [en]

    One of the biggest challenges in graphene applications is how one can fabricate 3D architectures comprising graphene sheets in which the resulting architectures have inherited graphene's excellent intrinsic properties but have overcome its shortcomings. Two series of 3D graphene monoliths (GMs) using zigzag or armchair graphene nanoribbons as building blocks and sp3 carbon chains as junction nodes are constructued, and calculations based on first principles are performed in order to predict their mechanical and electronic properties. The perfect match between sp2 nanoribbons and sp3 linkers results in favorable energy and mechanical/dynamic stability. Owing to their tailored motifs, wine-rack-like pores, and rigid sp3 linkers, these GMs possess high surface areas, appreciable mechanical strength, and tunable band gaps. Negative linear compressibilities in a wide range are found for the zigzag GMs. By solving the problems of zero gap and dimensionality of graphene sheets simultaneously, these GMs offer a viable strategy towards many applications, e.g., microelectronic devices, energy storage, molecular sieves, sensitive pressure detectors, and telecommunication line systems.

  • 13.
    Li, Jiantong
    et al.
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Naiini, Maziar M.
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Vaziri, Sam
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Lemme, Max C.
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits. University of Siegen, Germany.
    Östling, Mikael
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Inkjet Printing of MoS22014In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 24, no 41, p. 6524-6531Article in journal (Refereed)
    Abstract [en]

    A simple and efficient inkjet printing technology is developed for molybdenum disulfide (MoS2), one of the most attractive two-dimensional layered materials. The technology effectively addresses critical issues associated with normal MoS2 liquid dispersions (such as incompatible rheology, low concentration, and solvent toxicity), and hence can directly and reliably write uniform patterns of high-quality (5-7 nm thick) MoS2 nanosheets at a resolution of tens of micrometers. The technology efficiency facilitates the integration of printed MoS2 patterns with other components (such as electrodes), and hence allows fabricating various functional devices, including thin film transistors, photoluminescence patterns, and photodetectors, in a simple, massive and cost-effective manner while retains the unique properties of MoS2. The technology has great potential in a variety of applications, such as photonics, optoelectronics, sensors, and energy storage.

  • 14.
    Li, Shanghua
    et al.
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Furberg, Richard
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Toprak, Muhammet S.
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Palm, Björn E.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Muhammed, Mamoun
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Nature-inspired boiling enhancement by novel nanostructured macroporous surfaces2008In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 18, no 15, p. 2215-2220Article in journal (Refereed)
    Abstract [en]

    World energy crisis has triggered more attention to energy saving and energy conversion systems. Enhanced surfaces for boiling are among the applications of great interest since they can improve the energy efficiency of heat pumping equipment (i.e., air conditioners, heat pumps, refrigeration machines). Methods that are used to make the state-of-the-art enhanced Surfaces are often based on complicated mechanical machine tools, are quite material-consuming and give limited enhancement of the boiling heat transfer. Here, we present a new approach to fabricate enhanced surfaces by using a simple electrodeposition method with in-situ grown dynamic gas bubble templates. As a result, a well-ordered 3D macro-porous metallic surface layer with nanostructured porosity is obtained. Since the structure is built based on the dynamic bubbles, it is perfect for the bubble generation applications Such as nucleate boiling. At heat flux of 1W cm(-2), the heat transfer coefficient is enhanced over 17 times compared to a plain reference Surface. It's estimated that such ail effective boiling surface Would improve the energy efficiency of many heat Pumping machines with 10-30%. The extraordinary boiling performance is explained based on the structure characteristics.

  • 15. Ling, L.
    et al.
    Yuan, S.
    Wang, P.
    Zhang, H.
    Tu, L.
    Wang, J.
    Zhan, Y.
    Zheng, Lirong
    KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Solar Cells: Precisely Controlled Hydration Water for Performance Improvement of Organic–Inorganic Perovskite Solar Cells (Adv. Funct. Mater. 28/2016)2016In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 26, no 28Article in journal (Refereed)
  • 16. Ling, Li
    et al.
    Yuan, Sijian
    Wang, Pengfei
    Zhang, Huotian
    Tu, Li
    Wang, Jiao
    Zhan, Yiqiang
    Zheng, Lirong
    KTH, School of Information and Communication Technology (ICT), Industrial and Medical Electronics. KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK. Fudan Univ, Peoples R China.
    Precisely Controlled Hydration Water for Performance Improvement of Organic-Inorganic Perovskite Solar Cells2016In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 26, no 28, p. 5028-5034Article in journal (Refereed)
    Abstract [en]

    Recently, intensive studies on the role of water molecule in the formation of organic-inorganic perovskite film have been reported. However, not only the contradictive phenomena but also the complex processing technique has hindered the widespread use of water molecule in perovskite preparation. Here the hydration water is introduced into the precursors instead of water. By precisely controlling the content of hydration water, a smoother and more uniform perovskite film is obtained through a simple one-step spin coating method. The improvement of perovskite film quality leads to highly efficient planar perovskite solar cells. Summing up the device studies and the investigation of morphology, crystallization, and optical properties, the impact of water molecule in the formation of perovskite crystal and consequences of device performance is understood. Due to its universal adaptability and simplified process, precise control of hydration water is therefore of great utility to high quality perovskite films fabrication and large-scale production of this upcoming photovoltaic technology.

  • 17.
    Liu, Yingxin
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center. Stockholm Univ, Dept Mat & Environm Chem, S-10691 Stockholm, Sweden.
    Yu, Shu-Hong
    Univ Sci & Technol China, CAS Ctr Excellence Nanosci, Collaborat Innovat Ctr Suzhou Nano Sci & Technol, Div Nanomat & Chem,Hefei Natl Lab Phys Sci, Hefei 230026, Anhui, Peoples R China..
    Bergström, Lennart
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center. Stockholm Univ, Dept Mat & Environm Chem, S-10691 Stockholm, Sweden.
    Transparent and Flexible Nacre-Like Hybrid Films of Aminoclays and Carboxylated Cellulose Nanofibrils2018In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 28, no 27, article id 1703277Article in journal (Refereed)
    Abstract [en]

    Nacre and other biological composites are important inspirations for the design and fabrication of multifunctional composite materials. Transparent, strong, and flexible hybrid films of aminoclays (AC) and carboxylated cellulose nanofibrils (CNF) with a nacre-like microstructure at AC contents up to 60 wt% are prepared. The high transmittance of visible light is attributed to the high homogeneity of the hybrid films and to the relatively small refractive index contrast between the CNF-based matrix and synthetic AC. The strength and strain to failure of the hybrids are significantly higher than biogenic nacre and other nacre-mimicking nanocellulose-based materials, e.g., montmorillonite-CNF and graphene oxide-CNF composite films. The excellent mechanical properties are related to the ionic bonds between the negatively charged carboxylic groups on the CNF and the positively charged amine groups on the AC nanoparticles. This work illustrates the significance of tailoring the interactions between small clay particles and biopolymers in multifunctional materials with potential applications as printable barrier coatings and sub-strates for optoelectronics.

  • 18. MacLachlan, Andrew J
    et al.
    Rath, Thomas
    Cappel, Ute B
    Dowland, Simon A
    Amenitsch, Heinz
    Knall, Astrid-Caroline
    Buchmaier, Christine
    Trimmel, Gregor
    Nelson, Jenny
    Haque, Saif A
    Polymer/Nanocrystal Hybrid Solar Cells: Influence of Molecular Precursor Design on Film Nanomorphology, Charge Generation and Device Performance.2015In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 25, no 3, p. 409-420Article in journal (Refereed)
    Abstract [en]

    In this work, molecular tuning of metal xanthate precursors is shown to have a marked effect on the heterojunction morphology of hybrid poly(3-hexylthiophene-2,5-diyl) (P3HT)/CdS blends and, as a result, the photochemical processes and overall performance of in situ fabricated hybrid solar cells. A series of cadmium xanthate complexes is synthesized for use as in situ precursors to cadmium sulfide nanoparticles in hybrid P3HT/CdS solar cells. The formation of CdS domains is studied by simultaneous GIWAXS (grazing incidence wide-angle X-ray scattering) and GISAXS (grazing incidence small-angle X-ray scattering), revealing knowledge about crystal growth and the formation of different morphologies observed using TEM (transmission electron microscopy). These measurements show that there is a strong relationship between precursor structure and heterojunction nanomorphology. A combination of TAS (transient absorption spectroscopy) and photovoltaic device performance measurements is used to show the intricate balance required between charge photogeneration and percolated domains in order to effectively extract charges to maximize device power conversion efficiencies. This study presents a strong case for xanthate complexes as a useful route to designing optimal heterojunction morphologies for use in the emerging field of hybrid organic/inorganic solar cells, due to the fact that the nanomorphology can be tuned via careful design of these precursor materials.

  • 19.
    McCracken, J. M.
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Rauzan, B. M.
    Kjellman, J. C. E.
    Su, H. X.
    Rogers, S. A.
    Nuzzo, R. G.
    Ionic Hydrogels with Biomimetic 4D-Printed Mechanical Gradients: Models for Soft-Bodied Aquatic Organisms2019In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 29, no 28Article in journal (Refereed)
    Abstract [en]

    Direct-ink writing (DIW), a rapidly growing and advancing form of additive manufacturing, provides capacities for on-demand tailoring of materials to meet specific requirements for final designs. The penultimate challenge faced with the increasing demand of customization is to extend beyond modification of shape to create 4D structures, dynamic 3D structures that can respond to stimuli in the local environment. Patterning material gradients is foundational for assembly of 4D structures, however, there remains a general need for useful materials chemistries to generate gray scale gradients via DIW. Here, presented is a simple materials assembly paradigm using DIW to pattern ionotropic gradients in hydrogels. Using structures that architecturally mimic sea-jelly organisms, the capabilities of spatial patterning are highlighted as exemplified by selectively programming the valency of the ion-binding agents. Spatial gradients, when combined with geometry, allow for programming the flexibility and movement of iron oxide nanoparticle-loaded ionotropic hydrogels to generate 4D-printed structures that actuate in the presence of local magnetic fields. This work highlights approaches to 4D design complexity that exploits 3D-printed gray-scale/gradient mechanics.

  • 20.
    Mongkhontreerat, Surinthra
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Walter, Marie V.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Andrén, Oliver C. J.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Cai, Yanling
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Beyond state of the art honeycomb membranes: High performance ordered arrays from multi-programmable linear-dendritic block copolymers2015In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 25, no 30Article in journal (Refereed)
    Abstract [en]

    A new generation of honeycomb membranes is herein described from a novel library of multipurpose linear-dendritic block copolymers. These are accomplished by combining atom transfer radical polymerization together with dendrimer chemistry and click reactions. The resulted amorphous block copolymers, with T-g between 30 and 40 degrees C, display three important functions, i.e., pore generating aromatic groups, crosslinking azides, and multiple dendritic functional groups. All block copolymers enable the successful fabrication of honeycomb membranes through the facile breath figure method. The peripheral dendritic functionality is found to influence the porous morphologies from closed pored structure with pore size of 1.12 mu m(2) to open pore structure with pore size 10.26 mu m(2). Facile UV crosslinking of the azides yields membranes with highly durable structural integrity. Upon crosslinking, the pH and thermal stability are extended beyond the noncrosslinked membranes in which the porous integrity is maintained up to 400 degrees C and pH 1-14. Taking into account the straightforward and cost-efficient strategy to generate ordered, functional, and structurally stable honeycomb membranes on various solid substrates, it is apparent that these multipurpose block copolymers may unlock future applications including use as molds for soft lithography.

  • 21.
    Naureen, Shagufta
    et al.
    KTH, School of Information and Communication Technology (ICT), Material Physics, Semiconductor Materials, HMA.
    Shahid, Naeem
    KTH, School of Information and Communication Technology (ICT), Material Physics, Semiconductor Materials, HMA.
    Sanatinia, Reza
    KTH, School of Information and Communication Technology (ICT), Material Physics, Semiconductor Materials, HMA.
    Anand, Srinivasan
    KTH, School of Information and Communication Technology (ICT), Material Physics, Semiconductor Materials, HMA.
    Top-Down Fabrication of High Quality III–V Nanostructures by Monolayer Controlled Sculpting and Simultaneous Passivation2013In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 23, no 13, p. 1620-1627Article in journal (Refereed)
    Abstract [en]

    In the fabrication of IIIV semiconductor nanostructures for electronic and optoelectronic devices, techniques that are capable of removing material with monolayer precision are as important as material growth to achieve best device performances. A robust chemical treatment is demonstrated using sulfur (S)-oleylamine (OA) solution, which etches layer by layer in an inverse epitaxial fashion and simultaneously passivates the surface. The application of this process to push the limits of top-down nanofabrication is demonstrated by the realization of InP-based high optical quality nanowire arrays, with aspect ratios more than 50, and nanostructures with new topologies. The findings are relevant for other IIIV semiconductors and have potential applications in IIIV device technologies.

  • 22. Rehman, Hafeez Ur
    et al.
    Chen, Yujie
    Hedenqvist, Mikael S.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Li, Hua
    Xue, Wenchao
    Guo, Yunlong
    Guo, Yiping
    Duan, Huanan
    Liu, Hezhou
    Self-Healing Shape Memory PUPCL Copolymer with High Cycle Life2018In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 28, no 7, article id 1704109Article in journal (Refereed)
    Abstract [en]

    New polyurethane-based polycaprolactone copolymer networks, with shape recovery properties, are presented here. Once deformed at ambient temperature, they show 100% shape fixation until heated above the melting point, where they recover the initial shape within 22 s. In contrast to current shape memory materials, the new materials do not require deformation at elevated temperature. The stable polymer structure of polyurethane yields a copolymer network that has strength of 10 MPa with an elongation at break of 35%. The copolymer networks are self-healing at a slightly elevated temperature (70 degrees C) without any external force, which is required for existing self-healing materials. This allows for the new materials to have a long life of repeated healing cycles. The presented copolymers show features that are promising for applications as temperature sensors and activating elements.

  • 23. Shi, Shengwei
    et al.
    Sun, Zhengyi
    Bedoya-Pinto, Amilcar
    Graziosi, Patrizio
    Li, Xin
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Liu, Xianjie
    Hueso, Luis
    Dediu, Valentin A.
    Luo, Yi
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Fahlman, Mats
    Hybrid Interface States and Spin Polarization at Ferromagnetic Metal-Organic Heterojunctions: Interface Engineering for Efficient Spin Injection in Organic Spintronics2014In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 24, no 30, p. 4812-4821Article in journal (Refereed)
    Abstract [en]

    Ferromagnetic metal-organic semiconductor (FM-OSC) hybrid interfaces have been shown to play an important role for spin injection in organic spintronics. Here, 11,11,12,12-tetracyanonaptho-2,6-quinodimethane (TNAP) is introduced as an interfacial layer in Co-OSCs heterojunctions with an aim to tune the spin injection. The Co/TNAP interface is investigated by use of X-ray and ultraviolet photoelectron spectroscopy (XPS/UPS), near edge X-ray absorption fine structure (NEXAFS) and X-ray magnetic circular dichroism (XMCD). Hybrid interface states (HIS) are observed at Co/TNAP interfaces, resulting from chemical interactions between Co and TNAP. The energy level alignment at the Co/TNAP/OSCs interface is also obtained, and a reduction of the hole injection barrier is demonstrated. XMCD results confirm sizeable spin polarization at the Co/TNAP hybrid interface.

  • 24. Stuer, Michael
    et al.
    Bowen, Paul
    Cantoni, Marco
    Pecharroman, Carlos
    Zhao, Zhe
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Ceramics.
    Nanopore Characterization and Optical Modeling of Transparent Polycrystalline Alumina2012In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 22, no 11, p. 2303-2309Article in journal (Refereed)
    Abstract [en]

    Production of transparent ceramics has become a topic of resurgent interest in recent years, with its promise of near-net shaping appealing to applications ranging from biomedicine to solar energy. However, the mechanisms governing ceramic transparency, translucency, and opaqueness are not entirely understood. Models of both grain boundary and pore scattering have been proposed, but too often without sufficient experimental corroboration. An extensive experimental analysis of transparent alumina samples is presented, establishing a first direct link between the observed transparency, defect size, and porosity. Given the unprecedented experimental detail from the full 3D pore reconstruction from the FIB tomography, how to correctly interpret the experimentally observed transparency is additionally shown. The unprecedented experimental and theoretical agreement for the first time identifies the relative contributions of different scattering mechanisms, thereby paving the way forward for microstructural tuning of transparent polycrystalline alumina.

  • 25. Tian, Haining
    et al.
    Yang, Xichuan
    Pan, Jingxi
    Chen, Ruikui
    Liu, Ming
    Zhang, Qingyu
    Hagfeldt, Anders
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    A Triphenylamine Dye Model for the Study of Intramolecular Energy Transfer and Charge Transfer in Dye-Sensitized Solar Cells2008In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 18, no 21, p. 3461-3468Article in journal (Refereed)
    Abstract [en]

    A novel dye (2TPA-R), containing two triphenylamine (TPA) units connected by a vinyl group and rhodanine-3-acetic acid as the electron acceptor, is designed and synthesized successfully to reveal the working principles of organic dye in dye-sensitized solar cells (DSSCs). 2TPA and TPA-R, which consist of two TPA units connected by vinyl and a TPA unit linked with rhodanine-3-acetic acid, respectively, are also synthesized as references to study the intramolecular energy transfer (EnT) and charge transfer (ICT) processes of 2TPA-R in CH2Cl2 solution and on a TiO2 surface. The results suggest that the intramolecular EnT and ICT processes show a positive effect on the performance of DSSCs. However, the flexible structure and less-adsorbed amount of dye on TiO2 may make it difficult to improve the efficiency of DSSCs. This study on intramolecular EnT and ICT processes acts as a guide for the design and synthesis of efficient organic dyes in the future.

  • 26.
    Toprak, Muhammet S.
    et al.
    KTH, Superseded Departments, Materials Science and Engineering.
    Stiewe, C
    Platzek, D
    Williams, S
    Bertini, L
    Muller, Eckhard
    Gatti, C
    Zhang, Yu
    KTH, Superseded Departments, Materials Science and Engineering.
    Rowe, M
    Muhammed, Mamoun
    KTH, Superseded Departments, Materials Science and Engineering.
    The impact of nanostructuring on the thermal conductivity of thermoelectric CoSb32004In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 14, no 12, p. 1189-1196Article in journal (Refereed)
    Abstract [en]

    The high concentration of grain boundaries provided by nanostructuring is expected to lower the thermal conductivity of thermoelectric materials, which favors an increase in their thermoelectric figure-of-merit, ZT. A novel chemical alloying method has been used for the synthesis of nanoengineered-skutterudite CoSb3. The CoSb3 powders were annealed for different durations to obtain a set of samples with different particle sizes. The samples were then compacted into pellets by uniaxial pressing under various conditions and used for the thermoelectric characterization. The transport properties were investigated by measuring the Seebeck coefficient and the electrical and thermal conductivities in the temperature range 300 K to 650 K. A substantial reduction in the thermal conductivity of CoSb3 was observed with decreasing grain size in the nanometer region. For an average grain size of 140 nm, the thermal conductivity was reduced by almost an order of magnitude compared to that of a single crystalline or highly annealed polycrystalline material. The highest ZT value obtained was 0.17 at 611 K for a sample with an average grain size of 220 nm. The observed decrease in the thermal conductivity with decreasing grain size is quantified using a model that combines the macroscopic effective medium approaches with the concept of the Kapitza resistance. The compacted samples exhibit Kapitza resistances typical of semiconductors and comparable to those of Si-Ge alloys.

  • 27. Valenta, Jan
    et al.
    Fucikova, Anna
    Vacha, Frantisek
    Adamec, Frantisek
    Humpolickova, Jana
    Hof, Martin
    Pelant, Ivan
    Kusova, Katerina
    Dohnalova, Katerina
    Linnros, Jan
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Light-Emission Performance of Silicon Nanocrystals Deduced from Single Quantum Dot Spectroscopy2008In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 18, no 18, p. 2666-2672Article in journal (Refereed)
    Abstract [en]

    Spectra of individual silicon nanocrystals within porous Si grains are studied by the wide-field imaging microspectroscopy and their ON-OFF, blinking is detected by the confocal single-photon-counting microscopy. Observed spectral and blinking properties comprise all features reported before in differently prepared single Si nanocrystals (SiNCs). Former apparently contradictory results are shown to be due to different experimental conditions. When the effect of dark periods (OFF switching) is removed the common ultimate photoluminescence properties Of SiO2 passivated SiNCs are found, namely the quantum efficiency (QE) of about 10-20% up to the pumping rate corresponding to one exciton average excitation per quantum dot. At higher pump rates the QE is slowly decreasing as the 0.7th power of excitation. This is most likely due to Auger recombination which, however, seems to be weakened compared with measurements of nanocrystal assemblies. We conclude that SiNCs may be pumped above one exciton occupancy to yield a higher light emission, being advantageous for applications.

  • 28. Wang, Yajuan
    et al.
    Liang, Yongqi
    Zhang, Yongfei
    Yang, Wei
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry.
    Xu, Dongsheng
    Pushing the Envelope: Achieving an Open-Circuit Voltage of 1.18 V for Unalloyed MAPbI(3) Perovskite Solar Cells of a Planar Architecture2018In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 28, no 30, article id 1801237Article in journal (Refereed)
    Abstract [en]

    After an overwhelmingly fast increase during the period from 2009 to 2016, the power conversion efficiency of hybrid perovskite solar cells levels at approximate to 22% during the past two years. Every small advance to theoretical limits of the photovoltaic metrics will significantly deepen the understanding of internal processes inside the perovskite solar cells. Here, by introducing chloroform as the antisolvent, the one-step deposition method to fabricate methylammonium lead tri-iodide (MAPbI(3)) perovskite films under ambient air condition is optimized. With MAPbI(3) solar cells of a planar architecture, a record high V-oc of 1.18 V is obtained under simulated AM1.5 sunlight. The achievement helps pure MAPbI(3) to reestablish its potential as a model compound for research in hybrid perovskite solar cells. After systematic comparison on different electron transport layers (SnO2 and TiO2) and fluorine doped tin oxide (FTO) substrates of different roughness for photon trapping inside MAPbI(3) solar cells, the remaining 0.14 V V-oc loss is elucidated to be due to the poor luminescent property of the MAPbI(3) films.

  • 29.
    Westlund, Robert
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Malmström, Eva E.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Lopes, Cesar
    Öhgren, Johan
    Rodgers, Thomas
    Saito, Y.
    Kawata, S.
    Glimsdal, E.
    Lindgren, Mikael
    Efficient Nonlinear Absorbing Platinum(II) Acetylide Chromophores in Solid PMMA Matrices2008In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 18, no 13, p. 1939-1948Article in journal (Refereed)
    Abstract [en]

    Platinum(II) acetylides were incorporated into poly(methyl methacrylate) (PMMA) glasses to obtain solid-state nonlinear optical devices. We report on device fabrication, structural, chemical, and mechanical properties, as well as the optical limiting capabilities of the final solids. Two different guest-host systems are presented: 1) Dye molecules functionalized to be readily dispersed in methyl methacrylate (MMA) and subsequent in situ polymerization of the MMA yielding solid PMMA host matrices. 2) Dye molecules functionalized to copolymerize with MMA forming covalent bonds between the guest and the PMMA host matrix. A range of doped organic solids were prepared, reaching concentrations up to 13 wt% of the guest molecule. Raman spectra of the doped solid devices indicate that the chemical structure of the nonlinear dyes remains intact upon the polymerization of the solid matrix. Luminescence spectra confirm that the basic photophysical properties observed for the same solute molecules in THF are maintained also in the solid state. Optical power limiting (OPL) characterization reveal clamping levels for the dyes nonbonded to the solid host being less than 4 μJ at pulse energies up to 110 μJ at 532 nm (f/5 arrangement and 5 ns pulses), which is comparable to the performance of similar dyes in THF solutions. In contrast, the highly crosslinked solid possesses a higher clamping level (8 μj) at the same nominal concentration.

  • 30. Wigenius, Jens
    et al.
    Hamedi, Mahiar
    Inganäs, Olle
    Limits to Nanopatterning of Fluids on Surfaces in Soft Lithography2008In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 18, no 17, p. 2563-2571Article in journal (Refereed)
    Abstract [en]

    Soft lithographic microcontact printing using the residual polydimethylsiloxane (PDMS) found in elastomeric PDMS stamps is demonstrated to lead to unstable prints with sub-micrometer dimensions. The statics and dynamics of the process have been followed with time-resolved atomic force microscopy, imaging ellipsometry, water contact angle measurement, and optical diffraction. It is proposed that this instability places a fundamental limitation on patterning by macromolecular fluids, which is of general relevance to soft lithography and nanoimprint lithography with low viscosity polymers.

  • 31.
    Wu, Yunzhen
    et al.
    Dalian Univ Technol, Inst Energy Sci & Technol, DUT KTH Joint Educ & Res Ctr Mol Devices, State Key Lab Fine Chem, Dalian 116024, Peoples R China..
    Meng, Yanan
    Chinese Acad Sci, Changchun Inst Appl Chem, State Key Lab Rare Earth Resource Utilizat, Changchun 130022, Jilin, Peoples R China.;Univ Sci & Technol China, Sch Appl Chem & Engn, Hefei 230026, Anhui, Peoples R China..
    Hou, Jungang
    Dalian Univ Technol, Inst Energy Sci & Technol, DUT KTH Joint Educ & Res Ctr Mol Devices, State Key Lab Fine Chem, Dalian 116024, Peoples R China..
    Cao, Shuyan
    Dalian Univ Technol, Inst Energy Sci & Technol, DUT KTH Joint Educ & Res Ctr Mol Devices, State Key Lab Fine Chem, Dalian 116024, Peoples R China..
    Gao, Zhanming
    Dalian Univ Technol, Inst Energy Sci & Technol, DUT KTH Joint Educ & Res Ctr Mol Devices, State Key Lab Fine Chem, Dalian 116024, Peoples R China..
    Wu, Zhijian
    Chinese Acad Sci, Changchun Inst Appl Chem, State Key Lab Rare Earth Resource Utilizat, Changchun 130022, Jilin, Peoples R China..
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry.
    Orienting Active Crystal Planes of New Class Lacunaris Fe2PO5 Polyhedrons for Robust Water Oxidation in Alkaline and Neutral Media2018In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 28, no 35, article id 1801397Article in journal (Refereed)
    Abstract [en]

    Developing efficient and stable oxygen evolution reaction (OER) electrocatalysts is essential for realizing sustainable energy conversion, such as solar fuels. Although modulating active sites and electron transfer is of great significance to boost electrocatalysis activity, it still remains a big challenge to desirably actualize this goal. Herein, engineering of active sites and electronic framework is implemented via oriented modulation of crystal planes and construction of lacunaris architecture supported by ammonification-elicited simultaneous incorporation of nitrogen and oxygen-defect strategy. The new class porous nitrogen-incorporated Fe2PO5 with oxygen-defect (N-Fe2PO5-x) polyhedron with dominantly exposed {110} reactive facets exhibits superior performance toward water oxidation, achieving current densities of 10 mA cm(-2) at quite low overpotentials of 235 and 315 mV in alkaline and neutral media, respectively. Furthermore, density functional theoretical calculations reveal the energetically favorable {110} planes of lower absorption energy of intermediates and remolding of electronic density framework arising from the ammoniated elicitation process, contributing to excellent OER performance of lacunaris N-Fe2PO5-x polyhedrons. This work may offer a feasible guideline for regulating active sites and electron transfer to develop low-cost and highly efficient OER electrocatalysts in energy conversion systems.

  • 32.
    Xia, Chen
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Natural hematite for next-generation solid oxide fuel cells2015In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 26, no 6, p. 938-942Article in journal (Refereed)
    Abstract [en]

    Natural hematite ore is used as a novel electrolyte material for advanced solid oxide fuel cells (SOFCs). This hematite-based system exhibits a maximum power density of 225 mW cm −2 at 600 °C and reaches 467 mW cm −2 whenthe hematite is mixed with perovskite-structured La 0.6Sr0.4Co0.2Fe0.8O3–δ.These results demonstrate that natural materials for next-generation SOFCs can infl uence the multiutilization of natural resources, thereby affecting the environment and energy sustainability.

  • 33.
    Xia, Senlin
    et al.
    Tech Univ Munich, Dept Phys, Lehrstuhl Funkt Mat, James Franck Str 1, D-85748 Garching, Germany..
    Song, Lin
    Tech Univ Munich, Dept Phys, Lehrstuhl Funkt Mat, James Franck Str 1, D-85748 Garching, Germany..
    Hohn, Nuri
    Tech Univ Munich, Dept Phys, Lehrstuhl Funkt Mat, James Franck Str 1, D-85748 Garching, Germany..
    Wang, Kun
    Tech Univ Munich, Dept Phys, Lehrstuhl Funkt Mat, James Franck Str 1, D-85748 Garching, Germany..
    Grott, Sebastian
    Tech Univ Munich, Dept Phys, Lehrstuhl Funkt Mat, James Franck Str 1, D-85748 Garching, Germany..
    Opel, Matthias
    Bayer Akad Wissensch, Walther Meissner Inst, Walther Meissner Str 8, D-85748 Garching, Germany..
    Schwartzkopf, Matthias
    Deutsch Elektronen Synchrotron DESY, Notkestr 85, D-22603 Hamburg, Germany..
    Roth, Stephan V.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. Deutsch Elektronen Synchrotron DESY, Notkestr 85, D-22603 Hamburg, Germany..
    Mueller-Buschbaum, Peter
    Tech Univ Munich, Dept Phys, Lehrstuhl Funkt Mat, James Franck Str 1, D-85748 Garching, Germany.;Tech Univ Munich, Heinz Maier Leibnitz Zentrum MLZ, Lichtenbergstr 1, D-85748 Garching, Germany..
    Spray-Coating Magnetic Thin Hybrid Films of PS-b-PNIPAM and Magnetite Nanoparticles2019In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 29, no 15, article id 1808427Article in journal (Refereed)
    Abstract [en]

    Spray coating is employed to fabricate magnetic thin films composed of the diblock copolymer polystyrene-block-poly(N-isopropylacrylamide) and Fe3O4 magnetic nanoparticles (MNPs) functionalized with hydrophobic coatings. The kinetics of structure formation of the hybrid films is followed in situ with grazing incidence small angle X-ray scattering during the spray deposition. To gain a better understanding of the influence of MNPs on the overall structure formation, the pure polymer film is also deposited as a reference via an identical spray protocol. At the initial spraying stage, the hybrid film (containing 2 wt% of MNPs) exhibits a faster formation process of a complete film as compared to the reference. The existence of MNPs depresses the dewetting behavior of polymer films on the substrate at macroscale and simultaneously alters the polymer microphase separation structure orientation from parallel to vertical. As spraying proceeds, MNPs aggregate into agglomerates with increasing sizes. After the spray deposition is finished, both samples gradually reach an equilibrium state and magnetic films with stable structures are achieved in the end. Superconducting quantum interference device investigation reveals the superparamagnetic property of the sprayed hybrid film. Consequently, potential application of sprayed films in fields such as magnetic sensors or data storage appears highly promising.

  • 34. Xiao, Kai
    et al.
    Fu, Ying
    KTH, School of Biotechnology (BIO), Theoretical Chemistry.
    Liu, Yunqi
    Yu, Gui
    Zhai, Jin
    Jiang, Lei
    Hu, Wenping
    Shuai, Zhigang
    Luo, Yi
    KTH, School of Biotechnology (BIO), Theoretical Chemistry.
    Zhu, Daoben
    Photoelectrical characteristics of a C/CNx multiwalled nanotube2007In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 17, no 15, p. 2842-2846Article in journal (Refereed)
    Abstract [en]

    A nanotube diode fabricated from a single C/CNx multiwalled nanotube exhibits a large photocurrent and a large photovoltage under illumination. The current-voltage (I-V) characteristics of the diode indicate a clear rectification effect. By comparing the I-V characteristics of C, CNx, and C/CNx nanotube diodes, we show that the rectifying characteristics of the C/CNx diode arises from the molecular junction formed at the C/CNx interface where the C and CNx segments are chemically bonded. External radiation photochernically generates electrons and holes in the C/CNx nanotube, producing a large photocurrent because of the influence of the strong electric field in the vicinity of the C/CNx junction. These unique photoresponsive characteristics of C/CNx, nanotube junction diodes points to potential applications such as photovoltaic devices and photodiodes.

  • 35.
    Zhang, Yuning
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Andrén, Oliver C. J.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Coating Technology.
    Nordström, R.
    Fan, Yanmiao
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Malmsten, M.
    Mongkhontreerat, S.
    Malkoch, Michael
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Coating Technology.
    Off-Stoichiometric Thiol-Ene Chemistry to Dendritic Nanogel Therapeutics2019In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 29, no 18, article id 1806693Article in journal (Refereed)
    Abstract [en]

    A novel platform of dendritic nanogels is herein presented, capitalizing on the self-assembly of allyl-functional polyesters based on dendritic-linear-dendritic amphiphiles followed by simple cross-linking with complementary monomeric thiols via UV initiated off-stoichiometric thiol-ene chemistry. The facile approach enabled multigram creation of allyl reactive nanogel precursors, in the size range of 190–295 nm, being readily available for further modifications to display a number of core functionalities while maintaining the size distribution and characteristics of the master batch. The nanogels are evaluated as carriers of a spread of chemotherapeutics by customizing the core to accommodate each individual cargo. The resulting nanogels are biocompatible, displaying diffusion controlled release of cargo, maintained therapeutic efficacy, and decreased cargo toxic side effects. Finally, the nanogels are found to successfully deliver pharmaceuticals into a 3D pancreatic spheroids tumor model. © 2019 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

  • 36.
    Zhou, Xiamo
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Haraldsson, Klas Tommy
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Nania, Salvatore
    Karolinska Univ Hosp, Dept Clin Sci Intervent & Technol, Novum Hiss 6A, S-14196 Huddinge, Sweden..
    Ribet, Federico
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Palano, Giorgia
    Karolinska Univ Hosp, Dept Clin Sci Intervent & Technol, Novum Hiss 6A, S-14196 Huddinge, Sweden..
    Heuchel, Rainer
    Karolinska Univ Hosp, Dept Clin Sci Intervent & Technol, Novum Hiss 6A, S-14196 Huddinge, Sweden..
    Loehr, Matthias
    Karolinska Univ Hosp, Dept Clin Sci Intervent & Technol, Novum Hiss 6A, S-14196 Huddinge, Sweden..
    van der Wijngaart, Wouter Metsola
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Human Cell Encapsulation in Gel Microbeads with Cosynthesized Concentric Nanoporous Solid Shells2018In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 28, no 21, article id 1707129Article in journal (Refereed)
    Abstract [en]

    Encapsulation of therapeutic cells in core-shell microparticles has great promise for the treatment of a range of health conditions. Unresolved challenges related to control of the particle morphology, mechanical stability, and immunogenicity hinder dissemination of this promising approach. Here, a novel polymer material for cell encapsulation and a combined novel, easy to control, synthesis method are introduced. Core-shell cell encapsulation is demonstrated with a concentric core-shell morphology formed during a single UV exposure, resulting in particles that consist of a synthetic hydrogel core of polyethylene glycol diacrylate and a solid, but porous, shell of off-stoichiometric thiol-ene. The encapsulated human cells in 100 mu m diameter particles have >90% viability. The average shell thickness is controlled between 7 and 13 mu m by varying the UV exposure, and the shell is measured to be permeable to low molecular weight species (<180 Da) but impermeable to higher molecular weight species (>480 Da). The unique material properties and the orthogonal control of the microparticle core size, shell thickness, shell permeability, and shell surface properties address the key unresolved challenges in the field, and are expected to enable faster translation of novel cell therapy concepts from research to clinical practice.

  • 37.
    Zhu, Bin
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Raza, Rizwan
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Abbas, Ghazanfar
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Singh, Manish
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    An Electrolyte-Free Fuel Cell Constructed from One Homogenous Layer with Mixed Conductivity2011In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 21, no 13, p. 2465-2469Article in journal (Refereed)
    Abstract [en]

    Rather than using three layers, including an electrolyte, a working fuel cell is created that employs only one homogenous layer with mixed conductivity. The layer is a composite made from a mixture of metal oxide, Li(0.15)Ni(0.45)Zn(0.4) oxide, and an ionic conductor; ion-doped ceria. The single-component layer has a total conductivity of 0.1-1 S cm(-1) and exhibits both ionic and semiconducting properties. This homogenous one-layer device has a power output of more than 600 mW cm(-2) at 550 degrees C operating with H(2) and air. Overall conversion is completed in a similar way to a traditional fuel cell, even though the device does not include the electrolyte layer critical for traditional fuel-cell technologies using the three-component anode-electrolyte-cathode structure.

1 - 37 of 37
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