Provided is a thermoelectric material satisfying (MX).sub.1+a(TX.sub.2).sub.n and having a superlattice structure, wherein M is at least one element selected from the group consisting of Group 13, Group 14, and Group 15, T is at least one element selected from Group 5, X is a chalcogenide element, a is a real number satisfying 0<a<1, and n is a natural number of 1 to 3.

Provided are sulfide-based solid electrolyte with good ionic conductivity and an all-solid lithium ion battery using the same. A sulfide-based solid electrolyte having an argyrodite-type structure, wherein a composition of the sulfide-based solid electrolyte is represented by the formula:

Li.sub.8GeS.sub.5-xTe.sub.1+x

in which: −0.5≤x<0, 0<x≤0.375.

An electrically conductive thin film including: a material including a compound represented by Chemical Formula 1 and having a layered crystal structure,
Me.sub.mA.sub.a  Chemical Formula 1
wherein Me is Al, Ga, In, Si, Ge, Sn, A is S, Se, Te, or a combination thereof, and m and a each are independently a number selected so that the compound of Chemical Formula 1 is neutral; and a dopant disposed in the compound of Chemical Formula 1, wherein the dopant is a metal dopant that is different from Me and has an oxidation state which is greater than an oxidation state of Me, a non-metal dopant having a greater number of valence electrons than a number of valence electrons of A in Chemical Formula 1, or a combination thereof, and wherein the compound of Chemical Formula 1 includes a chemical bond which includes a valence electron of an s orbital of Me.

A method of synthesis of two-dimensional metal chalcogenide monolayers, such as WSe.sub.2 and MoSe.sub.2, is based on a chemical vapor deposition approach that uses H.sub.2Se or alkyl or aryl selenide precursors to form a reactive gas. The gaseous selenium precursor may be introduced into a tube furnace containing a metal precursor at a selected temperature, wherein the selenium and metal precursors react to form metal chalcogenide monolayers.

The present invention relates to a quantum dot and a preparation method therefor, and more specifically, to a novel quantum dot composite having high surface stability, and a preparation method therefor. The quantum dot composite according to the present invention constitutes a layered-structure ceramic composite in which the layered-structure ceramic comprises a polymer-quantum dot composite between the layers thereof.

A method of preparing monodisperse MX semiconductor nanocrystals can include contacting an M-containing precursor with an X donor to form a mixture, where the molar ratio between the M containing precursor and the X donor is large. Alternatively, if additional X donor is added during the reaction, a smaller ratio between the M containing precursor and the X donor can be used to prepare monodisperse MX semiconductor nanocrystals.

A homogeneous coating solution for forming a light-absorbing layer of a solar cell, the homogeneous solution including: at least one metal or metal compound selected from the group consisting of a group 11 metal, a group 13 metal, a group 11 metal compound and a group 13 metal compound; a Lewis base solvent; and a Lewis acid.

A nanocrystal capable of light emission includes a nanoparticle having photoluminescence having quantum yields of greater than 30%.

Composites having semiconductor structures embedded in a matrix are described. In an example, a composite includes a matrix material. A plurality of semiconductor structures is embedded in the matrix material. Each semiconductor structure includes an anisotropic nanocrystalline core composed of a first semiconductor material. Each semiconductor structure also includes a nanocrystalline shell composed of a second, different, semiconductor material at least partially surrounding the anisotropic nanocrystalline core. An insulator layer encapsulates each nanocrystalline shell and anisotropic nanocrystalline core pairing.

A method is provided for producing an article which is transparent to IR wavelength in the region of 4 μm to 9 μm. The method includes the steps of (a) Producing ultra-fine powders of ZnS, (b) followed by pretreatment of the ultra-fine powders under reduced gas conditions including H2, H2S, N2, Ar and mixtures there of (c) followed by vacuum (3×10.sup.−6 torr) treatment to remove oxygen and sulfates adsorbed to the surface disposing a plurality of nano-particles on a substrate, wherein said nanoparticles comprise ZnS with ultra-high purity of cubic phase; (b) subjecting the nano-particles to spark plasma sintering thereby producing a sintered ZnS product with IR transmission reaching 75% in the wavelength range of 4 μm to 9 μm.