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.

A system and method for performing is laser induced forward transfer (LIFT) of 2D materials is disclosed. The method includes generating a receiver substrate, generating a donor substrate, wherein the donor substrate comprises a back surface and a front surface, applying a coating to the front surface, wherein the coating includes donor material, aligning the front surface of the donor substrate to be parallel to and facing the receiver substrate, wherein the donor material is disposed adjacent to the target layer, and irradiating the coating through the back surface of the donor substrate with one or more laser pulses produced by a laser to transfer a portion of the donor material to the target layer. The donor material may include Bi.sub.2S.sub.3-xS.sub.x, MoS.sub.2, hexagonal boron nitride (h-BN) or graphene. The method may be used to create touch sensors and other electronic components.

A preparation method of fluorocarbon-coated VSe.sub.2 composite (VSe.sub.2@CF) anode electrode material, including: weighting and dissolving an acetylacetone oxovanadium (VO(acac).sub.2) and a selenium dioxide in a solvent to prepare a first solution with a concentration of 0.5-2 mol/L, and stirring the first solution for 0.5 h to obtain a dark green solution; adding the dark green solution with an organic acid to obtain a second solution; transferring the second solution to a polytetrafluoroethylene-lined high-pressure hydrothermal reactor, and holding at a heat insulation temperature for 15-30 h to obtain a third solution; after the third solution is cooled, suction filtering the cooled third solution, and washing the filtered third solution repeatedly to obtain a precipitate; drying the precipitate to obtain a black powder; co-mixing a citric acid solution with the black powder, stirring, ball milling, and drying; and heating up, holding, and finally cooling naturally to room temperature under inert atmosphere.

The disclosure relates to a method for preparing a 3D sponge structured carbonitride coated VSe.sub.2 composite (3D-VSe.sub.2@CN), belonging to the technical fields of electrode materials and preparation of batteries. In the disclosure, carbon, nitrogen and VSe.sub.2 are composited by using NaCl as a template so as to construct a 3D sponge structured carbonitride coated VSe.sub.2 composite. The 3D sponge structure can increase the structure stability of the material in the cyclic process, and the carbocanitride can increase the electron conductivity and activity sites of the material, so as to allow easier diffusion of potassium ions. Meanwhile, the stable structure can cause the clustering of VSe.sub.2 all the time. Thus, the prepared composite has good and stable rate capability and cycle stability. The process method is simple, low in cost, environmental-friendly, and suitable for large-scale industrial production.

Methods for making nanocomposites are provided. In an embodiment, such a method comprises combining a first type of nanostructure with a bulk material in water or an aqueous solution, the first type of nanostructure functionalized with a functional group capable of undergoing van der Waals interactions with the bulk material, whereby the first type of nanostructure induces exfoliation of the bulk material to provide a second, different type of nanostructure while inducing association between the first and second types of nanostructures to form the nanocomposite.

An object of the present invention is to provide semiconductor nanoparticles having high quantum efficiency (QY) and a narrow full width at half maximum (FWHM). Semiconductor nanoparticles according to an embodiment of the present invention are semiconductor nanoparticles including at least, In, P, Zn and S, wherein the semiconductor nanoparticles include the components other than In in the following ranges: 0.50 to 0.95 for P, 0.30 to 1.00 for Zn, 0.10 to 0.50 for S, and 0 to 0.30 for halogen, in terms of molar ratio with respect to In.

A quantum dot of the present invention is a nanocrystal represented by AgInE.sub.2 (E is at least one of tellurium, selenium, and sulfur) containing silver, indium, and chalcogen, in which a fluorescence wavelength is within a range of a near-infrared region of 700 to 1500 nm, a fluorescence full width at half maximum is 150 nm or less, and a fluorescence quantum yield is higher than 20%. In the present invention, an average particle diameter is preferably 1 nm or more and 15 nm or less. In addition, a method for producing a quantum dot of the present invention includes synthesizing a quantum dot represented by AgInE.sub.2 (E is at least one of tellurium, selenium, and sulfur) from a silver raw material, an indium raw material, and a chalcogenide raw material (chalcogenide is at least one of tellurium, selenium, and sulfur).

A method for making a transition metal dichalcogenide crystal having a chemical formula represented as MX.sub.2 is provided, wherein M represents a central transition metal element, and X represents a chalcogen element. The method includes providing a MX.sub.2 polycrystalline powder, a MX.sub.2 seed crystal, and a transport medium. The MX.sub.2 polycrystalline powder and the transport medium are placed in a first reaction chamber. The first reaction chamber and the MX.sub.2 seed crystal are placed in a second reaction chamber having a source end and a deposition end opposite to the source end. The first reaction chamber is placed at the source end, and the MX.sub.2 seed crystal is placed at the deposition end.

A semiconductor nanoparticle, a production method thereof, and an electroluminescent device including the same. The production method includes: combining a magnesium precursor and an additive with a chalcogen precursor in a reaction medium including an organic solvent and an organic ligand; heating the reaction medium to a reaction temperature; and reacting the magnesium precursor and the chalcogen precursor in the presence of the additive to form a magnesium chalcogenide, wherein the semiconductor nanoparticle comprises the magnesium chalcogenide, wherein the magnesium chalcogenide comprises magnesium; and selenium, sulfur, or a combination thereof, and wherein the additive includes a hydride compound including an alkali metal, calcium, barium, aluminum, or a combination thereof.