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.

There is provided a thermoelectric conversion material containing Cu and Se as main components, an element M including one or two or more elements selected from Group 10 elements and Group 11 elements excluding Cu, and optional element of Te. The thermoelectric conversion material is represented by the following chemical formula. Chemical Formula: Cu.sub.xSe.sub.(1−y)Te.sub.yM.sub.z,

1.95≤x<2.05,0≤y≤0.1,0.002≤z≤0.03.

The present invention relates to a preparation method of a stretchable inorganic thermoelectric thin film and the stretchable inorganic thermoelectric thin film prepared by the method.

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 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 semiconductor nanocrystal include a first I-III-VI semiconductor material and have a luminescence quantum yield of at least 10%, at least 20%, or at least 30%. The nanocrystal can be substantially free of toxic elements. Populations of the nanocrystals can have an emission FWHM of no greater than 0.35 eV.

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.

A chalcogen-containing compound of the following Chemical Formula 1, which may have decreased thermal conductivity and improved power factor in the low temperature region, and thus exhibit an excellent thermoelectric figure of merit, a method for preparing the same, and a thermoelectric element including the same:
V.sub.1Sn.sub.a−xIn.sub.xSb.sub.2Te.sub.a+3  [Chemical Formula 1]
wherein V, a and x are as defined in the specification.