The invention relates to Chevrel-phase materials and methods of preparing these materials utilizing a precursor approach. The Chevrel-phase materials are useful in assembling electrodes, e.g., cathodes, for use in electrochemical cells, such as rechargeable batteries. The Chevrel-phase materials have a general formula of Mo.sub.6Z.sub.8 (Z=sulfur) or Mo.sub.6Z.sup.1.sub.8-yZ.sup.2.sub.y (Z.sup.1=sulfur; Z.sup.2=selenium), and partially cuprated Cu.sub.1Mo.sub.6S.sub.8 as well as partially de-cuprated Cu.sub.1-xMg.sub.xMo.sub.6S.sub.8 and the precursors have a general formula of M.sub.xMo.sub.6Z.sub.8 or M.sub.xMo.sub.6Z.sup.1.sub.8-yZ.sup.2.sub.y, M=Cu. The cathode containing the Chevrel-phase material in accordance with the invention can be combined with a magnesium-containing anode and an electrolyte.

A thermoelectric conversion element includes a thermoelectric conversion material portion having a compound semiconductor composed of first base material element A and second base material element B and represented by A.sub.x-cB.sub.y with value of x being smaller by c with respect to a compound A.sub.xB.sub.y according to a stoichiometric ratio, a first electrode disposed in contact with the thermoelectric conversion material portion, and a second electrode disposed in contact with the thermoelectric conversion material portion and apart from the first electrode. An A-B phase diagram includes a first region corresponding to low temperature phase, second region corresponding to high temperature phase, and third region corresponding to coexisting phase, sandwiched between the low temperature phase and the high temperature phase, in which the low and high temperature phases coexist. A temperature at a boundary between the first region and the third region changes monotonically with a change in c.

A porous membrane comprising stacked layers of nanosheets, each nanosheet comprising one to three atomic layers of a 2D material comprising or consisting of one or more transition metal dichalcogenides is provided. The nanosheets have pores and the membrane comprises a network of water permeation pathways including through-pathways formed by the pores, horizontal pathways formed by gaps between the layers, and vertical pathways formed by gaps between adjacent nanosheets and stacking defects between the layers. Also provided is a method for making the membrane.

A core-shell quantum dot including a core including a first semiconductor nanocrystal, the first semiconductor nanocrystal including zinc, tellurium, and selenium and a semiconductor nanocrystal shell disposed on the core, the semiconductor nanocrystal shell including zinc and selenium, sulfur, or a combination thereof and a production thereof are disclosed, wherein the core-shell quantum dot does not include cadmium, lead, mercury, or a combination thereof, wherein the core-shell quantum dot(s) includes chlorine, wherein in the core-shell quantum dot, a mole ratio of chlorine with respect to tellurium is greater than or equal to about 0.01:1 and wherein a quantum efficiency of the core-shell quantum dot is greater than or equal to about 10%.

The present embodiments relate to a method for manufacturing a two-dimensional material using a top-down method, the method includes the steps of preparing a bulk crystal, forming a metal layer on the bulk crystal, and then attaching a thermal release tape on the metal layer, exfoliating a two-dimensional material to which the metal layer and the thermal release tape have been attached from the bulk crystal, transferring the two-dimensional material to which the metal layer and the thermal release tape have been attached onto a substrate, and removing the thermal release tape and the metal layer from the substrate onto which the two-dimensional material has been transferred.

Provided are a chalcogenide material, and a device and a memory device each including the same. The chalcogenide material may include: germanium (Ge) as a first component; arsenic (As) as a second component; at least one element selected from selenium (Se) and tellurium (Te) as a third component; and at least one element selected from the elements of Groups 2, 16, and 17 of the periodic table as a fourth component, wherein a content of the first component may be from 5 at % to 30 at %, a content of the second component may be from 20 at % to 40 at %, a content of the third component may be from 25 at % to 75 at %, and a content of the fourth component may be from 0.5 at % to 5 at %.

A thermoelectric conversion element includes a thermoelectric conversion material portion having a compound semiconductor composed of first base material element A and second base material element B and represented by A.sub.x-cB.sub.y with value of x being smaller by c with respect to a compound A.sub.xB.sub.y according to a stoichiometric ratio, a first electrode disposed in contact with the thermoelectric conversion material portion, and a second electrode disposed in contact with the thermoelectric conversion material portion and apart from the first electrode. An A-B phase diagram includes a first region corresponding to low temperature phase, second region corresponding to high temperature phase, and third region corresponding to coexisting phase, sandwiched between the low temperature phase and the high temperature phase, in which the low and high temperature phases coexist. A temperature at a boundary between the first region and the third region changes monotonically with a change in c.

The present invention relates to a photoelectric film and a fabrication method thereof, and in particular, to a layered polycrystalline lead selenide (PbSe) film and a fabrication method thereof. The fabrication method mainly includes: (1) fabricating a dense PbSe layer on a substrate through chemical bath deposition (CBD); (2) fabricating a loose plumbonacrite (Pb.sub.10O(OH).sub.6(CO.sub.3).sub.6) layer on the dense PbSe layer through CBD; (3) placing a sample with the dense PbSe layer and the Pb.sub.10O(OH).sub.6(CO.sub.3).sub.6 layer in a selenium ion-containing solution to allow an ion exchange reaction to finally form the layered polycrystalline PbSe film. The fabrication method has the advantages of simple process, low cost, and high controllability. The PbSe film fabricated by the method is composed of a lower dense polycrystalline cubic PbSe layer and an upper loose polycrystalline cubic PbSe layer, which can be widely used in the fabrication of components in the field of photoelectric conversion or thermoelectric conversion, such as infrared (IR) sensors, solar cells, laser emitters, and thermoelectric converters.

The disclosure provides a II-II-VI alloy quantum dot, a preparation method and application thereof. The preparation method includes: step S1: reacting a precursor containing a second Group II element and a precursor containing a first Group VI element to form a II-VI semiconductor nanocluster; step S2: mixing the II-VI semiconductor nanocluster with a precursor containing a first Group II element, and performing cation exchange and in-situ growth to obtain a first system containing the II-II-VI alloy quantum dot.

In a method for producing nanoparticles of copper selenide, a flowable copper precursor is formed by combining a copper starting material and a ligand, and a flowable selenium precursor is formed by suspending a selenium starting material in a liquid. Then a flowable copper-selenium mixture including a lower-polarity solvent is formed by combining the flowable copper precursor and the flowable selenium precursor. The flowable copper-selenium mixture is conducted through at least one heating unit, and the nanoparticles of copper selenide are isolated in an oxygen-depleted environment. The isolation includes combining a solution containing the nanoparticles of copper selenide and a deoxygenated, higher-polarity solvent to precipitate the nanoparticles.