Sodium chloride-assisted CVD enables controlled synthesis of large single-layered MoS.

Thin-layer MoS has attracted much interest because of its potential in diverse technologies, including electronics, optoelectronics and catalysis these few years. In particular, finding a simple and effective solution for large-scale growth of thin-layer semiconductor nanosheets is a prerequisite for achieving their excellent performance. In this paper, we investigated four different substrates under identical conditions for MoS film growth and observed a strong correlation between substrate surface conditions and MoS growth.

Piezoelectricity of BiSe Nanosheet.

BiSe, one of the most extensively studied topological insulators, has received significant attention, and abundant research has been dedicated to exploring its surface electronic properties. However, little attention has been given to its piezoelectric properties. Herein, we investigate the piezoelectric response in a five-layer BiSe nanosheet using scanning probe microscopy (SPM) techniques.

Defect engineering of two-dimensional Nb-based oxynitrides for visible-light-driven water splitting to produce H and O.

Two-dimensional (2D) Nb-based oxynitrides are promising visible-light-responsive photocatalysts for the water splitting reaction, but their photocatalytic activity is degraded by the formation of reduced Nb species and O vacancies. To understand the influence of nitridation on the formation of crystal defects, this study synthesized a series of Nb-based oxynitrides through the nitridation of LaKNaNbTaO ( = 0, 0.2, 0.

Preparation of mesoporous nitrogen-doped titania comprising large crystallites with low thermal conductivity.

Reducing the thermal conductivity () of mesoporous N-doped titania (TiO) is crucial for the development of TiO-based materials that exhibit excellent electronic, photochemical, and thermoelectric properties. Mesopores can contribute to the reduction of phonon scattering, and the scattering effect due to the randomness of crystal interfaces should be significantly reduced to clarify the role of mesopores in reducing thermal conductivity. Highly ordered mesoporous N-doped TiO comprising large crystallites was prepared with silica colloidal crystals as a template into which a Ti source was introduced, followed by calcination with urea.

Ferroelectricity and Piezoelectricity in 2D Van der Waals CuInPS Ferroelectric Tunnel Junctions.

CuInP2S6 (CIPS) is a novel two-dimensional (2D) van der Waals (vdW) ferroelectric layered material with a Curie temperature of ~315 K, making it promising for great potential applications in electronic and photoelectric devices. Herein, the ferroelectric and electric properties of CIPS at different thicknesses are carefully evaluated by scanning probe microscopy techniques. Some defects in some local regions due to Cu deficiency lead to a CuInP2S6-InPS (CIPS-IPS) paraelectric phase coexisting with the CIPS ferroelectric phase.

Flexible -Type Abundant Chalcopyrite/PEDOT:PSS/Graphene Hybrid Film for Thermoelectric Device Utilizing Low-Grade Heat.

Combining inorganic thermoelectric (TE) materials with conductive polymers is one promising strategy to develop flexible thermoelectric (FTE) films and devices. As most inorganic materials tried up until now in FTE composites are composed of scarce or toxic elements, and -type FTE materials are particularly desired, we combined the abundant, inexpensive, nontoxic Zn-doped chalcopyrite (CuZnFeS, = 0.01, 0.

Preparation of Ordered Nanoporous Indium Tin Oxides with Large Crystallites and Individual Control over Their Thermal and Electrical Conductivities.

Metal oxides are considered suitable candidates for thermoelectric materials owing to their high chemical stabilities. The formation of ordered nanopores within these materials, which decreases thermal conductivity (κ), has attracted significant interest. However, the electrical conductivity (σ) of reported nanoporous metal oxides is low, owing to electron scattering at the thin pore walls and many grain boundaries formed by small crystallites.

Thermoelectric Performance of Cr Doped and Cr-Fe Double-Doped Higher Manganese Silicides with Adjusted Carrier Concentration and Significant Electron-Phonon Interaction.

Polycrystalline higher manganese silicides MnCrSi ( = 0, 0.10, 0.20) with Cr single doping and MnCrFeSi ( = 0.

Thermoelectric Enhancement of Silicon Membranes by Ultrathin Amorphous Films.

We propose a simple, low-cost, and large-area method to increase the thermoelectric figure of merit (ZT) in silicon membranes by the deposition of an ultrathin aluminum layer. Transmission electron microscopy showed that short deposition of aluminum on a silicon substrate covers the surface with an ultrathin amorphous film, which, according to recent theoretical works, efficiently destroys phonon wave packets. As a result, we measured 30-40% lower thermal conductivity in silicon membranes covered with aluminum films while the electrical conductivity was not affected.

Thermoelectric Properties of Variants of CuMnTe with Spinel-Related Structure.

Thermoelectric properties of CuMnTe, which is antiferromagnetic with a Néel temperature T = 50 K and crystallizes in a spinel-related structure, have been investigated comprehensively here. The phase transition occurring at temperatures 463 and 723 K is studied by high-temperature X-ray diffraction (XRD) and differential scanning calorimetry (DSC), and its effect on thermoelectric properties is examined. Hypothetically CuMnTe is semiconducting according to the formula (Cu)(Mn)(Te), while experimentally it shows p-type metallic conduction behavior, exhibiting electrical conductivity σ = 2500 Ω cm and Seebeck coefficient α = 20 μV K at 325 K.

Genetic heterogeneity of oesophageal cancer in high-incidence areas of southern and northern China.

Background And Objective: Oesophageal cancer is one of the most common and deadliest cancers worldwide. Our previous population-based study reported a high prevalence of oesophageal cancer in Chaoshan, Guangdong Province, China. Ancestors of the Chaoshan population migrated from the Taihang Mountain region of north-central China, which is another high-incidence area for oesophageal cancer.