scholarly journals Charge Carrier Transport in Van Der Waals Semiconductor InSe Intercalated with RbNO3 Probed by Direct Current Methods

2021 ◽  
Vol 11 (11) ◽  
pp. 5181
Author(s):  
Zakhar R. Kudrynskyi ◽  
Illya V. Mintyanskii ◽  
Petro I. Savitskii ◽  
Zakhar D. Kovalyuk

Layered van der Waals (vdW) semiconductors show great promise to overcome limitations imposed by traditional semiconductor materials. The synergistic combination of vdW semiconductors with other functional materials can offer novel working principles and device concepts for future nano- and optoelectronics. Herein, we investigate the influence of the intercalation of semiconducting n-type InSe vdW crystals with ferroelectric rubidium nitrate (RbNO3) on the transport of charge carriers along and across the layers. The apparent maxima in the temperature dependences of the Hall coefficient are explained in the framework of a model that predicts, along with three-dimensional carriers, the existence of two-dimensional ones contributing only to the conductivity along the layers. The revealed increase of the conductivity anisotropy and its activation variation with temperature, which is mainly due to a decrease of the conductivity across the layers, confirm a two-dimensionalization of electron gas in n-InSe after insertion of the ferroelectric. From the numerical analysis, we determined the densities of carriers of both types, concentrations of donors and acceptors, as well as the value of the interlayer barrier.

2014 ◽  
Vol 1706 ◽  
Author(s):  
Hiroaki Wakayama ◽  
Hirotaka Yonekura ◽  
Yasuaki Kawai

ABSTRACTPeriodically ordered nanohetero inorganic structures offer great promise due to their unique electric, ionic, magnetic, and photonic properties. Many studies have focused on the formation of periodically ordered nano-hetero inorganic structures through layer-by-layer adsorption, sputtering, and self-assembly methods. However, the construction of three-dimensional periodically ordered nanohetero inorganic structures with desired sizes and morphologies remains a great challenge. We present a simple method for producing three-dimensional periodically ordered inorganic nanoheterostructures with controlled shape and size by replicating self-assembled block copolymers (BCPs) containing precursors of metals and metal oxides. Precursors were dissolved with BCPs in a solvent. Upon evaporation of the solvent, each precursor was selectively introduced into a separate polymer block. Application of an external magnetic field (10 T) to the BCP-precursor composites resulted in a phase transition of from spheres to hexagonal cylinders. Subsequent pyrolytic removal of the BCPs produced periodically ordered nanoheterostructures that were structural replicates of the precursor–BCP composites. Self-assembled nano-hetero inorganic structures of nanoparticles, nanorods and layers in a matrix were produced. The morphology and domain size can be tailored by controlling the molecular weight and relative block length of block copolymers. The controlled size and morphology of the inorganic nanoheterostructures demonstrate the method’s utility for producing highly functional materials.


2003 ◽  
Vol 8 (5-6) ◽  
pp. 30-32
Author(s):  
B.E. Paton ◽  
◽  
E.A. Asnis ◽  
S.P. Zabolotin ◽  
P.I. Baranskii ◽  
...  

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 430
Author(s):  
Vasso Apostolopoulos ◽  
Joanna Bojarska ◽  
Tsun-Thai Chai ◽  
Sherif Elnagdy ◽  
Krzysztof Kaczmarek ◽  
...  

Peptides are fragments of proteins that carry out biological functions. They act as signaling entities via all domains of life and interfere with protein-protein interactions, which are indispensable in bio-processes. Short peptides include fundamental molecular information for a prelude to the symphony of life. They have aroused considerable interest due to their unique features and great promise in innovative bio-therapies. This work focusing on the current state-of-the-art short peptide-based therapeutical developments is the first global review written by researchers from all continents, as a celebration of 100 years of peptide therapeutics since the commencement of insulin therapy in the 1920s. Peptide “drugs” initially played only the role of hormone analogs to balance disorders. Nowadays, they achieve numerous biomedical tasks, can cross membranes, or reach intracellular targets. The role of peptides in bio-processes can hardly be mimicked by other chemical substances. The article is divided into independent sections, which are related to either the progress in short peptide-based theranostics or the problems posing challenge to bio-medicine. In particular, the SWOT analysis of short peptides, their relevance in therapies of diverse diseases, improvements in (bio)synthesis platforms, advanced nano-supramolecular technologies, aptamers, altered peptide ligands and in silico methodologies to overcome peptide limitations, modern smart bio-functional materials, vaccines, and drug/gene-targeted delivery systems are discussed.


2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Michael R. Sinko ◽  
Sergio C. de la Barrera ◽  
Olivia Lanes ◽  
Kenji Watanabe ◽  
Takashi Taniguchi ◽  
...  

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1510 ◽  
Author(s):  
Mohammad Ehsan Taghavizadeh Yazdi ◽  
Simin Nazarnezhad ◽  
Seyed Hadi Mousavi ◽  
Mohammad Sadegh Amiri ◽  
Majid Darroudi ◽  
...  

The use of naturally occurring materials in biomedicine has been increasingly attracting the researchers’ interest and, in this regard, gum tragacanth (GT) is recently showing great promise as a therapeutic substance in tissue engineering and regenerative medicine. As a polysaccharide, GT can be easily extracted from the stems and branches of various species of Astragalus. This anionic polymer is known to be a biodegradable, non-allergenic, non-toxic, and non-carcinogenic material. The stability against microbial, heat and acid degradation has made GT an attractive material not only in industrial settings (e.g., food packaging) but also in biomedical approaches (e.g., drug delivery). Over time, GT has been shown to be a useful reagent in the formation and stabilization of metal nanoparticles in the context of green chemistry. With the advent of tissue engineering, GT has also been utilized for the fabrication of three-dimensional (3D) scaffolds applied for both hard and soft tissue healing strategies. However, more research is needed for defining GT applicability in the future of biomedical engineering. On this object, the present review aims to provide a state-of-the-art overview of GT in biomedicine and tries to open new horizons in the field based on its inherent characteristics.


Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4164
Author(s):  
Elizabeth Diederichs ◽  
Maisyn Picard ◽  
Boon Peng Chang ◽  
Manjusri Misra ◽  
Amar Mohanty

Three-dimensional (3D) printing manufactures intricate computer aided designs without time and resource spent for mold creation. The rapid growth of this industry has led to its extensive use in the automotive, biomedical, and electrical industries. In this work, biobased poly(trimethylene terephthalate) (PTT) blends were combined with pyrolyzed biomass to create sustainable and novel printing materials. The Miscanthus biocarbon (BC), generated from pyrolysis at 650 °C, was combined with an optimized PTT blend at 5 and 10 wt % to generate filaments for extrusion 3D printing. Samples were printed and analyzed according to their thermal, mechanical, and morphological properties. Although there were no significant differences seen in the mechanical properties between the two BC composites, the optimal quantity of BC was 5 wt % based upon dimensional stability, ease of printing, and surface finish. These printable materials show great promise for implementation into customizable, non-structural components in the electrical and automotive industries.


1994 ◽  
Vol 340 ◽  
Author(s):  
L. E. Rumaner ◽  
F.S. Ohuchi

ABSTRACTAlthough heteroepitaxy of lattice-matched and lattice-mismatched materials leading to artificially structured materials has resulted in impressive performance in various electronics devices, material combinations are usually limited by lattice matching constraints. A new concept for fabricating material systems using the atomically abrupt and low dimensional nature of layered materials, called van der Waals epitaxy (VDWE), has been developed. GaSe (Eg = 2.1 eV) has been deposited on the three dimensional surface of GaAs (111) using a molecular beam deposition system. GaSe was evaporated from a single Knudsen source, impinging on a heated substrate. Even with a lattice mismatch of 6% between the substrate and the growing film, good quality single crystal films were grown as determined by RHEED. The films have further been analyzed using a complementary combination of XPS and X-ray reflectivity.


2006 ◽  
Vol 62 (6) ◽  
pp. 1010-1018 ◽  
Author(s):  
Vladislav A. Blatov ◽  
Gregory D. Ilyushin ◽  
Olga A. Blatova ◽  
Nataly A. Anurova ◽  
Alexej K. Ivanov-Schits ◽  
...  

In terms of the Voronoi–Dirichlet partition of the crystal space, definitions are given for such concepts as `void', `channel' and `migration path' for inorganic structures with three-dimensional networks of chemical bonds. A number of criteria are proposed for selecting significant voids and migration channels for alkali cations Li+–Cs+ based on the average characteristics of the Voronoi–Dirichlet polyhedra for alkali metals in oxygen-containing compounds. A general algorithm to analyze the voids in crystal structures has been developed and implemented in the computer package TOPOS. This approach was used to predict the positions of Li+ and Na+ cations and to analyze their possible migration paths in the solid superionic materials Li3 M 2P3O12 (M = Sc, Fe; LIPHOS) and Na1 + x Zr2Si x P3 − x O12 (NASICON), whose framework structures consist of connected M octahedra and T tetrahedra. Using this approach we determine the most probable places for charge carriers (coordinates of alkali cations) and the dimensionality of their conducting sublattice with high accuracy. The theoretically calculated coordinates of the alkali cations in MT frameworks are found to correlate to within 0.33 Å with experimental data for various phases of NASICON and LIPHOS. The proposed method of computer analysis is universal and suitable for investigating fast-ion conductors with other conducting components.


Author(s):  
Yuchuan Pan ◽  
Xiaochi Liu ◽  
Junqiang Yang ◽  
Won Jong Yoo ◽  
Jian Sun

2007 ◽  
Vol 994 ◽  
Author(s):  
Pawel Kaminski ◽  
Stanislaw Jankowski ◽  
Roman Kozlowski ◽  
Janusz Bedkowski

AbstractA computational intelligence algorithm has been applied to extracting trap parameters from the photocurrent relaxation waveforms recorded at the temperature range of 20-320 K for semi-insulating (SI) InP samples. Using the inverse Laplace transform procedure, the spectral surfaces, visualized in the three dimensional space as functions of temperature and emission rate, are calculated. The processes of thermal emission of charge carriers from defect centers manifest themselves as the sharp folds on the spectral surface. Using a set of Gaussian functions, the approximating surface is created and the ridgelines of the folds, giving the temperature dependences of the emission rate for the detected traps, are determined. The approximation is performed using the support vector machine (SVM) algorithm which allows for trading off between the model complexity and fitting accuracy. The new approach is exemplified by comparing the defect structure of SI InP wafers after annealing in iron phosphide and pure phosphorous atmospheres.


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