92 results match your criteria: "Institute of Material Physics[Affiliation]"

Organic Thin Films Based on DPP-DTT:C60 Blends Deposited by MAPLE.

Nanomaterials (Basel)

November 2020

National Institute for Lasers, Plasma and Radiation Physics, 409 Atomistilor Street, 077125 Magurele, Romania.

The matrix-assisted pulsed laser evaporation (MAPLE) technique was used for depositing thin films based on a recently developed conjugated polymer, poly[2,5-(2-octyldodecyl)-3,6-diketopyrrolopyrrole-alt-5,5-(2,5-di(thien-2-yl)thieno [3,2-b]thiophene)] (DPP-DTT) and fullerene C60 blends. The targets used in the MAPLE process were obtained by freezing chloroform solutions with different DPP-DTT:C60 weight ratios, with the MAPLE deposition being carried at a low laser fluence, varying the number of laser pulses. The structural, morphological, optical, and electrical properties of the DPP-DTT:C60 blend layers deposited by MAPLE were investigated in order to emphasize the influence of the DPP-DTT:C60 weight ratio and the number of laser pulses on these features.

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The ubiquitin-proteasome system regulates the level of proteins within cells through controlled proteolysis. In some diseases, the system function is dysregulated turning the ubiquitin-proteasome complex into a target for drug development. The redox behavior of proteasome inhibitors, epoxyketone and boronated peptides carfilzomib, oprozomib and delanzomib was investigated by voltammetric methods using glassy carbon and boron doped diamond electrodes.

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Efficient charge collection in photovoltaics is a key issue toward their high performance. Despite the promising performance of colloidal quantum dot (CQD)-based photovoltaics (CQDPVs), they suffer significant dissipation of photocurrent due to imperfect surface passivation of the CQD hole transport layer (HTL) by a single 1,2-ethaneditihol (EDT) ligand. To address the critical drawback of existing CQDPVs, we offer a hybrid passivation strategy, including both EDT and thiocyanate (SCN).

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In the present study, a magnetic adsorbent, rhein-coated magnetic FeO nanoparticle (RMNP), for Pb and Mg had been developed, and adsorption mechanism was studied via low-field NMR. RMNP was characterized by TEM, FTIR, and XRD. RMNP could adsorb and remove Pb and Mg from water and was successfully applied to remove Pb and Mg from wastewater, with satisfactory recovery rates and high adsorption capacities.

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Epitaxial growth of highly stable perovskite CsPbBr/nZnS/Al core/multi-shell quantum dots with aluminium self-passivation.

Nanotechnology

September 2020

School of Materials Science and Engineering, Institute of Material Physics, Key Laboratory of Display Materials and Photoelectric Devices, Ministry of Education, and Tianjin Key Laboratory for Photoelectric Materials and Devices, and National Demonstration Center for Experimental Function Materials Education, Tianjin University of Technology, Tianjin 300384, People's Republic of China.

As a new type of colloidal nanocrystals, perovskite quantum dots (QDs) have received widespread attention. Water and oxygen in the air can affect the luminous efficiency of quantum dots, which can degrade the surface of QDs and affect their luminescence efficiency. Herein we discuss the synthesis of high-quality QDs using an uncomplicated coating method by which an ultrathin epitaxial Al self-passivation layer bearing homogeneous ligands can be coated on the QDs.

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Novel Self-Powered Photodetector with Binary Photoswitching Based on SnS/TiO Heterojunctions.

ACS Appl Mater Interfaces

May 2020

School of Materials Science and Engineering, Institute of Material Physics, Key Laboratory of Display Materials and Photoelectric Devices, Ministry of Education, and Tianjin Key Laboratory for Photoelectric Materials and Devices, Tianjin University of Technology, Tianjin 300384, China.

Binary photoresponse characteristics can help realize optical signal processing and logic operations. UV photodetectors (PDs) with SnS nanoflakes and TiO nanorod arrays (NRs) show a novel binary photoswitching behavior (change in current from positive to negative) by manipulating the light wavelength without an external power source, utilizing the interfacial recombination of the photogenerated carriers in the type-I SnS/TiO heterojunctions. The enhanced responsivity (), detectivity (), and fast photoresponse time for self-powered SnS/TiOPDs can be achieved by adjusting the phase ratio of SnS and SnS nanoflakes.

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EIS and XPS investigations on the interaction of hemin with p- and n-doped GaAs(100) electrodes in PBS solution revealed significant differences concerning both the adsorbed species and the mechanism of the redox process caused by dopant nature. XPS data show that hemin is adsorbed on p-GaAs(100) by its carboxyl groups and adopts a vertical position favorable to a polymeric film formation whereas on n-GaAs(100), the adsorbed hemin is monomeric and has a rather planar configuration involving mainly the OH groups of the organic molecule. Hemin gives rise to a reversible redox process at the p-GaAs(100) electrode whereas at n-GaAs(100), there is only one reduction wave of a considerably lower current density appearing at a more negative potential.

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Segregation is a crucial phenomenon, which has to be considered in functional material design. Segregation processes in perovskite oxides have been the subject of ongoing scientific interest, since they can lead to a modification of properties and a loss of functionality. Many studies in oxide thin films have focused on segregation toward the surface using a variety of surface-sensitive analysis techniques.

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Stable Luminescence of CsPbBr/CdS Core/Shell Perovskite Quantum Dots with Al Self-Passivation Layer Modification.

ACS Appl Mater Interfaces

October 2019

School of Materials Science and Engineering, Institute of Material Physics, Key Laboratory of Display Materials and Photoelectric Devices, Ministry of Education, and Tianjin Key Laboratory for Photoelectric Materials and Devices, and National Demonstration Center for Experimental Function Materials Education , Tianjin University of Technology, Tianjin 300384 , China.

Perovskite quantum dots (PQDs) are among the most important luminescent semiconducting materials; however, they are unstable. Exposure to light, heat, and air can lead to irreversible degradation, which results in fluorescence quenching. Therefore, defects in PQDs significantly limit their practical application.

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Hydrogen polysulfides (HS, n > 1), as the oxidized forms of HS, have attracted increasing attention these years due to their involvement in signaling transduction and cytoprotective processes. It is necessary to detect HS in living systems for the study of their functions. In this work, we report a BODIPY-based near-infrared emitting fluorescence probe NIR-PHS1, with "turn-on" response, rapid response rate (within 10 min), outstanding selectivity and excellent sensitivity (detection limit = 12 nM) response towards HS.

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Operando magnetic susceptibility measurements of sodium ion cathode materials during repetitive electrochemical cycling enable a continuous and bulk sensitive monitoring of the transition metal oxidation states. Such measurements on NaxV2(PO4)3 identified vanadium to be the only ion undergoing oxidation/reduction processes upon battery operation. For the initial battery charging-discharging cycle as well as for the first cycle after prolonged room temperature storage, however, peculiarities within the magnetic susceptibility measurements indicate parasitic side reactions, likely on the cathode surface.

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The majority of eukaryotic regulated protein turnover is performed by the proteasome, a multi-catalytic enzyme. Due to the fact that proteasome enzyme abnormal functioning was observed in different malignant cells, the proteasome is becoming a target for medical treatment. In order to evaluate the mechanisms of action of pharmaceutical compounds on proteasome enzyme inhibition, detecting and characterizing its activity is essential.

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Behavior of Molybdenum⁻Vanadium Mixed Oxides in Selective Oxidation and Disproportionation of Toluene.

Materials (Basel)

March 2019

University of Bucharest, Department of Organic Chemistry, Biochemistry & Catalysis, Faculty of Chemistry, 4-12, Blv. Regina Elisabeta, 030018 Bucharest, Romania.

This study deals with the behavior of molybdenum⁻vanadium (Mo/V) mixed oxides catalysts in both disproportionation and selective oxidation of toluene. Samples containing different Mo/V ratios were prepared by a modified method using tetradecyltrimethylammonium bromide and acetic acid. The catalysts were characterized using several techniques: nitrogen adsorption⁻desorption isotherms, X-Ray diffraction (XRD), ammonia temperature-programmed desorption (TPD-NH₃), temperature-programmed reduction by hydrogen (H₂-TPR), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, Fourier-transform infrared-spectroscopy (FTIR) and ultraviolet-visible spectroscopies (UV⁻VIS).

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Atomic scale analyses of {\bb Z}-module defects in an NiZr alloy.

Acta Crystallogr A Found Adv

November 2018

CNRS-Laboratoire de Métallurgie de l'UMR 8247, IRCP Chimie-ParisTech, 11 rue Pierre et Marie Curie, 75005 Paris, France.

Some specific structures of intermetallic alloys, like approximants of quasicrystals, have their unit cells and most of their atoms located on a periodic fraction of the nodes of a unique {\bb Z}-module [a set of the irrational projections of the nodes of a (N > 3-dimensional) lattice]. Those hidden internal symmetries generate possible new kinds of defects like coherent twins, translation defects and so-called module dislocations that have already been discussed elsewhere [Quiquandon et al. (2016).

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We report significant photoelectrochemical activity of Y-doped BiFeO (Y-BFO) epitaxial thin films deposited on Nb:SrTiO substrates. The Y-BFO photoanodes exhibit a strong dependence of the photocurrent values on the thickness of the films, and implicitly on the induced epitaxial strain. The peculiar crystalline structure of the Y-BFO thin films and the structural changes after the PEC experiments have been revealed by high resolution X-ray diffraction and transmission electron microscopy investigations.

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Antimicrobial properties of ternary eutectic aluminum alloys.

Biometals

October 2018

Radiation Biology Department, German Aerospace Center (DLR e.V.), Institute of Aerospace Medicine, Cologne, Germany.

Several Escherichia coli deletion mutants of the Keio collection were selected for analysis to better understand which genes may play a key role in copper or silver homeostasis. Each of the selected E. coli mutants had a deletion of a single gene predicted to encode proteins for homologous recombination or contained functions directly linked to copper or silver transport or transformation.

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TiO Nanorod Arrays Based Self-Powered UV Photodetector: Heterojunction with NiO Nanoflakes and Enhanced UV Photoresponse.

ACS Appl Mater Interfaces

April 2018

School of Materials Science and Engineering, Institute of Material Physics, Key Laboratory of Display Materials and Photoelectric Devices, Ministry of Education, Tianjin Key Laboratory for Photoelectric Materials and Devices, and National Demonstration Center for Experimental Function Materials Education , Tianjin University of Technology, Tianjin 300384 , China.

The self-powered ultraviolet photodetectors (UV PDs) have attracted increasing attention due to their potential applications without consuming any external power. It is important to obtain the high-performance self-powered UV PDs by a simple method for the practical application. Herein, TiO nanorod arrays (NRs) were synthesized by hydrothermal method, which were integrated with p-type NiO nanoflakes to realize a high performance pn heterojunction for the efficient UV photodetection.

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Transparent Nb-doped TiO films with the [001] preferred orientation for efficient photocatalytic oxidation performance.

Dalton Trans

November 2017

Institute of Material Physics, Key Laboratory of Display Materials and Photoelectric Devices of Ministry of Education, Key Laboratory for Optoelectronic Materials and Devices of Tianjin, College of Materials Science and Engineering, Tianjin University of Technology, Tianjin 300191, China.

Doping and tailoring of the crystal orientation are two main strategies to improve the photocatalytic properties of TiO films. Herein, we introduce a novel route for obtaining Nb-doped TiO anatase films with the [001] preferred orientation by thermal oxidation of the [100]-oriented Nb-doped TiN film prepared by magnetron sputtering. Comprehensive analyses with X-ray diffraction, Raman scattering, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy indicate that the proportion of high-energy (001) facets of the Nb-doped TiO film is more than 90% and the Nb ion is successfully doped into the film without destroying the crystallinity and orientation.

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Non-volatile resistance change under electric stimulation in many metal-oxides is a promising path to next generation memory devices. However, the underlying mechanisms are still not fully understood. In situ transmission electron microscopy experiments provide a powerful tool to elucidate these mechanisms.

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Photoelectric response properties under UV/red light irradiation of ZnO nanorod arrays coated with vertically aligned MoS nanosheets.

Nanotechnology

October 2017

Institute of Material Physics, Key Laboratory of Display Materials and Photoelectric Devices, Ministry of Education, and Tianjin Key Laboratory for Photoelectric Materials and Devices, Tianjin University of Technology, Tianjin 300384, People's Republic of China.

MoS with layered structure and distinct physical properties has attracted attention for electronic or optoelectronic devices. The photoelectric response properties of MoS/ZnO heterojunctions based devices fabricated by spin-coating MoS nanosheets solutions on ZnO nanorod arrays (NRs) were investigated. The results revealed that MoS nanosheets were vertically aligned on the surface of ZnO NRs and the devices exhibit good photoresponse stability and reproducibility under UV and red light illuminations.

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Influence of TiO and Si on the exciton-phonon interaction in PbI and CdS semiconductors evidenced by Raman spectroscopy.

J Phys Condens Matter

September 2017

Laboratory of Optical Processes in Nanostructured Materials, National Institute of Material Physics, PO Box MG-7, Magurele-Bucharest 077125, Romania. Faculty of Physics, University of Bucharest, POB MG-11, Magurele-Bucharest 077125, Romania.

The exciton-phonon interaction, considered as a stimulated Raman scattering process, is studied in different semiconductor mixtures: PbI/TiO, PbI/Si and CdS/Si. Raman spectra recorded at excitation wavelengths of 514.5 and 488 nm for PbI and CdS, respectively, reveal a strong enhancement of the Raman lines peaked at 97 and 305 cm, evaluated by the ratio I /I between the relative intensities of the spectra recorded in the temperature range of 88-300 K.

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Magnetic Nanoparticles for Hepatocellular Carcinoma Diagnosis and Therapy.

J Gastrointestin Liver Dis

September 2016

Research Center of Gastroenterology and Hepatology of Craiova, Craiova, Romania; Department of Endoscopy, Gastrointestinal Unit, Copenhagen University Herlev Hospital, Copenhagen, Denmark.

Hepatocellular carcinoma (HCC) is the most common primary tumor of the liver, ranking as the second most common cause of death from cancer worldwide. Magnetic nanoparticles (MNPs) have been used so far in tumor diagnosis and treatment, demonstrating great potential and promising results. In principle, three different approaches can be used in the treatment of tumors with superparamagnetic iron oxide nanoparticles: magnetically induced hyperthermia, drug targeting and selective suppression of tumor growth.

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Development of Solution-Processed ZnO Nanorod Arrays Based Photodetectors and the Improvement of UV Photoresponse via AZO Seed Layers.

ACS Appl Mater Interfaces

August 2016

Institute of Material Physics, Key Laboratory of Display Materials and Photoelectric Devices, Ministry of Education, and Tianjin Key Laboratory for Photoelectric Materials and Devices, Tianjin University of Technology, Tianjin 300384, China.

Designing a rational structure and developing an efficient fabrication technique for bottom-up devices offer a promising opportunity for achieving high-performance devices. In this work, we studied how Al-doped ZnO (AZO) seed layer films influence the morphology and optical and electrical properties for ZnO aligned nanorod arrays (NRs) and then the performance of ZnO NRs based ultraviolet photodetectors (UV PDs) with Au/ZnO NRs Schottky junctions and p-CuSCN/n-ZnO NRs heterojunctions. The PD with AZO thin film with 0.

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BiFeO3 is one of the most promising multiferroic materials but undergoes two major drawbacks: low dielectric susceptibility and high dielectric loss. Here we report high in-plane dielectric permittivity (ε' ∼2500) and low dielectric loss (tan δ < 0.01) obtained on Bi0.

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Continuous white luminescence of ZnS:Pb2+ and core/shell ZnS:Pb2+/ZnS nanocrystals.

J Nanosci Nanotechnol

November 2011

Institute of Material Physics, Tianjin University of Technology, Tianjin 300384, People's Republic of China.

High-quality water-soluble ZnS:Pb2+ nanocrystals were synthesized via a simple chemical codepositing method. The as-synthesized ZnS:Pb2+ nanocrystals show high monodispersity and crystallinity with a narrow size distribution (3.2 +/- 0.

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