High Thermoelectric zT in n-Type Silver Selenide films at Room Temperature

2017 ◽  
Vol 8 (8) ◽  
pp. 1702024 ◽  
Author(s):  
Jaime Andres Perez-Taborda ◽  
Olga Caballero-Calero ◽  
Liliana Vera-Londono ◽  
Fernando Briones ◽  
Marisol Martin-Gonzalez
Keyword(s):  
Room Temperature ◽  
Silver Selenide

Critical role of nanoinclusions in silver selenide nanocomposites as a promising room temperature thermoelectric material

2019 ◽  
Vol 7 (9) ◽  
pp. 2646-2652 ◽  
Author(s):  
Khak Ho Lim ◽  
Ka Wai Wong ◽  
Yu Liu ◽  
Yu Zhang ◽  
Doris Cadavid ◽  
...  
Keyword(s):  
Seebeck Coefficient ◽  
Room Temperature ◽  
Opposite Effect ◽  
Critical Role ◽  
Free Carrier ◽  
Silver Selenide ◽  
Band Bending ◽  
Seebeck Coefficients ◽  
Electrical Conductivities

The introduction of nonmetal nanoinclusions within Ag2Se results in an interphase band bending that promotes electron filtering and increase Seebeck coefficient. Similar loading of metal nanoinclusions provided an opposite effect-modulating free carrier concentration, as characterized by superior electrical conductivities and lower Seebeck coefficients.

scholarly journals Thermoelectricity: High Thermoelectric zT in n-Type Silver Selenide films at Room Temperature (Adv. Energy Mater. 8/2018)

2018 ◽  
Vol 8 (8) ◽  
pp. 1870033 ◽  
Author(s):  
Jaime Andres Perez-Taborda ◽  
Olga Caballero-Calero ◽  
Liliana Vera-Londono ◽  
Fernando Briones ◽  
Marisol Martin-Gonzalez
Keyword(s):  
Room Temperature ◽  
Silver Selenide ◽  
Energy Mater

Effect of Nature of Surfactant on the Formation of β-Ag2Se Nanoparticles and Optical Properties of β-Ag2Se and ZnS/β-Ag2Se Nanocomposite

2015 ◽  
Vol 30 ◽  
pp. 96-105
Author(s):  
V. Andal ◽  
G. Buvaneswari
Keyword(s):  
Room Temperature ◽  
Metallic Silver ◽  
Silver Selenide ◽  
Nano Composite ◽  
Room Temperature Photoluminescence ◽  
Triton X100 ◽  
Room Temperature Photoluminescence Spectrum ◽  
Se Nanoparticles ◽  
Ft Ir ◽  
Surfactant Assisted

Surfactant assisted synthetic route was followed to prepare silver selenide (β-Ag2Se) nanoparticles. The effect of three different surfactants viz., Triton X100, SDS and CTAB in the formation of silver selenide nanoparticles had been examined. Pure and crystalline β-Ag2Se nanophase was obtained in the presence of Triton X100 and SDS. However, the presence of CTAB leads to metallic silver formation. Nano Composite of β-Ag2Se and ZnS was fabricated in the presence of glycine as a molecular linker. The products were characterized by different techniques such as XRD, FT-IR, SEM and TEM. Room temperature photoluminescence spectrum of the ZnS/ β-Ag2Se nanocomposite exhibited two emission peaks at around 286 nm and 392 nm with enhanced intensity (lex= 250 nm).

Synthesis and Optimum of Silver Selenide Nanopowder via Room Temperature Conversion Method

2012 ◽  
Vol 535-537 ◽  
pp. 349-352 ◽  
Author(s):  
Feng Xia Yang ◽  
Feng Xian Liu ◽  
Xiao Ling Yu
Keyword(s):  
Reaction Time ◽  
Optimum Condition ◽  
Chemical Reaction ◽  
Room Temperature ◽  
Lattice Parameter ◽  
Chemical Mechanism ◽  
Silver Selenide ◽  
Conversion Method

Silver selenide nanopowder was prepared by a room temperature conversion method, in which selenide powder(Se) and ethylenediamine (NH2CH2CH2NH2) were used as precursors. Chemical mechanism were studied by several comparative experiments. It was found that chemical reaction was taken place between Se and Ag ions through ethylenediamine. The influence of the chemical reaction time on the phase and microstructure was investigated. The results showed that the reaction was not completely if the reaction time was lower than 4h, on the contrary, some plane begin to split if the reaction time was longer than 12h. While the size and lattice parameter increase firstly with increasing time and then reduce. The results were discussed and the optimum condition was obtianed.

Solvothermal Preparation and Thermal Phase Change Behaviors of Nanosized Tetragonal-Phase Silver Selenide (Ag2Se)

2013 ◽  
Vol 850-851 ◽  
pp. 128-131 ◽  
Author(s):  
Jun Li Wang ◽  
Hui Feng ◽  
Wei Ling Fan
Keyword(s):  
Transition Temperature ◽  
Phase Change ◽  
Photoelectron Spectroscopy ◽  
Tetragonal Phase ◽  
Room Temperature ◽  
Variable Temperature ◽  
Cubic Phase ◽  
Silver Selenide ◽  
X Ray ◽  
Change Behaviors

Nanocrystalline silver selenide (Ag2Se) with an average diameter of 100 nm were prepared by a facile solvothermal method. X-ray energy dispersive (EDS) spectroscopy and X-ray photoelectron spectroscopy (XPS) studies confirmed that the products were pure Ag2Se. Room-temperature powder X-ray diffraction (XRD) measurements indicated that the as-prepared Ag2Se nanocrystals exhibit a metastable tetragonal polymorphic phase, rather than the common orthorhombic phase at room temperature. The variable-temperature XRD and differential scanning calorimetry (DSC) thermal analysis techniques were used to investigate the phase change behaviors of the tetragonal Ag2Se nanocrystals, and the results showed that the low-temperature tetragonal phase transforms to the high-temperature cubic phase at about 106 °C. This transition temperature is lower by ~30 °C than the orthorhombic-cubic transition temperature (133140 °C) previously reported for Ag2Se. Meanwhile, two exothermic peaks, loaded at 61 and 89 °C, respectively, were detected in the cooling DSC scan for the cubic to tetragonal phase transition, and the reason was discussed.

Dependence of Intergranular Fracture on Boundary Topography and Cohesion

1973 ◽  
Vol 31 ◽  
pp. 150-151
Author(s):  
J. E. Doherty ◽  
A. F. Giamei ◽  
B. H. Kear ◽  
C. W. Steinke
Keyword(s):  
Grain Boundary ◽  
Room Temperature ◽  
Nickel Base Superalloy ◽  
Boundary Shear ◽  
Room Temperature Ductility ◽  
Solid Solution Matrix ◽  
Nickel Base ◽  
Solution Matrix ◽  
Different Levels ◽  
Base Superalloy

Recently we have been investigating a class of nickel-base superalloys which possess substantial room temperature ductility. This improvement in ductility is directly related to improvements in grain boundary strength due to increased boundary cohesion through control of detrimental impurities and improved boundary shear strength by controlled grain boundary micros true tures.For these investigations an experimental nickel-base superalloy was doped with different levels of sulphur impurity. The micros tructure after a heat treatment of 1360°C for 2 hr, 1200°C for 16 hr consists of coherent precipitates of γ’ Ni3(Al,X) in a nickel solid solution matrix.

Hepatocyte Alterations in Guinea Pigs FED Polychlorinated Biphenyls (PCBs), Dibenzodioxins (PCDD), AND DIBENZOFURANS (PCDF)

1982 ◽  
Vol 40 ◽  
pp. 56-57
Author(s):  
J. N. Turner ◽  
D. N. Collins
Keyword(s):  
Guinea Pigs ◽  
Room Temperature ◽  
Dose Group ◽  
Methyl Cellulose ◽  
Uranyl Acetate ◽  
Target Organ ◽  
Office Building ◽  
Lead Citrate ◽  
Control Groups ◽  
Cooling Fluid

A fire involving an electric service transformer and its cooling fluid, a mixture of PCBs and chlorinated benzenes, contaminated an office building with a fine soot. Chemical analysis showed PCDDs and PCDFs including the highly toxic tetra isomers. Guinea pigs were chosen as an experimental animal to test the soot's toxicity because of their sensitivity to these compounds, and the liver was examined because it is a target organ. The soot was suspended in 0.75% methyl cellulose and administered in a single dose by gavage at levels of 1,10,100, and 500mgm soot/kgm body weight. Each dose group was composed of 6 males and 6 females. Control groups included 12 (6 male, 6 female) animals fed activated carbon in methyl cellulose, 6 males fed methyl cellulose, and 16 males and 10 females untreated. The guinea pigs were sacrificed at 42 days by suffocation in CO2. Liver samples were immediately immersed and minced in 2% gluteraldehyde in cacadylate buffer at pH 7.4 and 4°C. After overnight fixation, samples were postfixed in 1% OsO4 in cacodylate for 1 hr at room temperature, embedded in epon, sectioned and stained with uranyl acetate and lead citrate.

Domain Formation in Synthetic Quartz

1971 ◽  
Vol 29 ◽  
pp. 156-157
Author(s):  
Joseph J. Comer
Keyword(s):  
Electron Beam ◽  
Room Temperature ◽  
Domain Formation ◽  
Synthetic Quartz ◽  
Transmission Electron ◽  
Black Spots ◽  
Diffraction Mode ◽  
Domain Boundaries ◽  
Kikuchi Lines ◽  
Straight Lines

Domains visible by transmission electron microscopy, believed to be Dauphiné inversion twins, were found in some specimens of synthetic quartz heated to 680°C and cooled to room temperature. With the electron beam close to parallel to the [0001] direction the domain boundaries appeared as straight lines normal to <100> and <410> or <510> directions. In the selected area diffraction mode, a shift of the Kikuchi lines was observed when the electron beam was made to traverse the specimen across a boundary. This shift indicates a change in orientation which accounts for the visibility of the domain by diffraction contrast when the specimen is tilted. Upon exposure to a 100 KV electron beam with a flux of 5x 1018 electrons/cm2sec the boundaries are rapidly decorated by radiation damage centers appearing as black spots. Similar crystallographio boundaries were sometimes found in unannealed (0001) quartz damaged by electrons.

A Liquid Nitrogen Cooled Stage for STEM

1974 ◽  
Vol 32 ◽  
pp. 444-445
Author(s):  
Louis T. Germinario
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Liquid Nitrogen ◽  
Room Temperature ◽  
Objective Lens ◽  
Thermal Drift ◽  
Specimen Holder ◽  
Resolution Capability ◽  
Focal Position

A liquid nitrogen stage has been developed for the JEOL JEM-100B electron microscope equipped with a scanning attachment. The design is a modification of the standard JEM-100B SEM specimen holder with specimen cooling to any temperatures In the range ~ 55°K to room temperature. Since the specimen plane is maintained at the ‘high resolution’ focal position of the objective lens and ‘bumping’ and thermal drift la minimized by supercooling the liquid nitrogen, the high resolution capability of the microscope is maintained (Fig.4).

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