The present disclosure provides a method of preparing a chalcogen containing solution that is hydrazine free and hydrazinium free, wherein the method comprises: providing a predetermined amount of elemental chalcogen; providing a predetermined amount of elemental sulfur; providing an amine solvent; and combining the predetermined amount of elemental chalcogen and the predetermined amount of elemental sulfur in the amine solvent, thereby dissolving the elemental chalcogen and the elemental sulfur in the amine solvent. The chalcogen containing solution can advantageously be used as a precursor for the formation of a chalcogen containing layer on a substrate.

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.

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.

A mixed conductor represented by Formula 1:
A.sub.4±xTi.sub.5−yG.sub.zO.sub.12−δ  Formula 1 wherein, in Formula 1, A is a monovalent cation, G is at least one of a monovalent cation, a divalent cation, a trivalent cation, a tetravalent cation, a pentavalent cation, or a hexavalent cation, with the proviso that G is not Ti or Cr, wherein 0<x<2, 0.3<y<5, 0<z<5, and 0<δ≤3.

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 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.

A direct solution method based on a versatile amine-thiol solvent mixture which dissolves elemental metals, metal salts, organometallic complexes, metal chalcogenides, and metal oxides is described. The metal containing and metal chalcogenide precursors can be prepared by dissolving single or multiple metal sources, chalcogens, and/or metal chalcogenide compounds separately, simultaneously, or stepwise. Multinary metal chalcogenides containing at least one of copper, zinc, tin, indium, gallium, cadmium, germanium, and lead, with at least one of sulfur, selenium, or both are obtained from the above-mentioned metal chalcogenide precursors in the form of thin films, nanoparticles, inks, etc. Furthermore, infiltration of metal containing compounds into a porous structure can be achieved using the amine-thiol based precursors. In addition, due to the appreciable solubility of metal sources, metal chalcogenides, and metal oxides in the mixture of amine(s) and thiol(s), this solvent mixture can be used to remove these materials from a system.

Described are Zn.sub.xCd.sub.1-xS.sub.ySe.sub.1-y/ZnS.sub.zSe.sub.1-z core/shell nanocrystals, CdTe/CdS/ZnS core/shell/shell nanocrystals, optionally doped Zn(S,Se,Te) nano- and quantum wires, and SnS quantum sheets or ribbons, methods for making the same, and their use in biomedical and photonic applications, such as sensors for analytes in cells and preparation of field effect transistors.