A quantum dot including a core that includes a first semiconductor nanocrystal including zinc and selenium, and optionally sulfur and/or tellurium, and a shell that includes a second semiconductor nanocrystal including zinc, and at least one of sulfur or selenium is disclosed. The quantum dot has an average particle diameter of greater than or equal to about 13 nm, an emission peak wavelength in a range of about 440 nm to about 470 nm, and a full width at half maximum (FWHM) of an emission wavelength of less than about 25 nm. A method for preparing the quantum dot, a quantum dot-polymer composite including the quantum dot, and an electronic device including the quantum dot is also disclosed.

Provided is a semiconductor nanoparticle complex dispersion liquid in which semiconductor nanoparticles are dispersed in a polar dispersion medium at a high mass fraction, and in which high fluorescence quantum efficiency (QY) is maintained. A semiconductor nanoparticle complex dispersion liquid according to an embodiment includes a semiconductor nanoparticle complex dispersed in an organic dispersion medium, wherein: the semiconductor nanoparticle complex is composed of two or more ligands including an aliphatic thiol ligand and a polar ligand, and a semiconductor nanoparticle with the ligands coordinated to the surface thereof; the ligands are composed of an organic group and a coordinating group; the organic group of the polar ligand includes a hydrophilic functional group; and an SP value of the organic dispersion medium is 8.5 or more.

Provided is a semiconductor nanoparticle complex composition and the like in which a semiconductor nanoparticle complex is dispersed at a high concentration and which has high fluorescence quantum yield. A semiconductor nanoparticle complex composition in which a semiconductor nanoparticle complex is dispersed in a dispersion medium, wherein: the semiconductor nanoparticle complex has a semiconductor nanoparticle and a ligand coordinated to the surface of the semiconductor nanoparticle; the ligand includes an organic group; the dispersion medium is a monomer or a prepolymer; the semiconductor nanoparticle complex composition further includes a crosslinking agent; and a mass fraction of the semiconductor nanoparticle in the semiconductor nanoparticle complex composition is 30% by mass or more.

A process for preparing stacks of metal chalcogenide flakes includes: (a) reacting together a source of the metal atom of the target metal chalcogenide with a source of the chalcogenide atom of the target metal chalcogenide, in the presence of a spacer, so as to produce flakes of the metal chalcogenide; (b) depositing metal chalcogenide flakes obtained using step (a) onto a substrate to form a stack of assembled metal chalcogenide flakes, wherein the spacer contains an alkyl chain linked to a functional group able to bond to the metal chalcogenide surface, said alkyl chain having a length of less than 18 carbon atoms, preferably between 6 and 14 carbon atoms.

A process for preparing stacks of metal chalcogenide flakes includes: (a) reacting together a source of the metal atom of the target metal chalcogenide with a source of the chalcogenide atom of the target metal chalcogenide, in the presence of a spacer, so as to produce flakes of the metal chalcogenide; (b) depositing metal chalcogenide flakes obtained using step (a) onto a substrate to form a stack of assembled metal chalcogenide flakes, wherein the spacer contains an alkyl chain linked to a functional group able to bond to the metal chalcogenide surface, said alkyl chain having a length of less than 18 carbon atoms, preferably between 6 and 14 carbon atoms.

A method for producing a quantum dot including crystalline nanoparticle fluorescent material, wherein, using a first precursor solution and a second precursor solution containing different elements each other, the second precursor solution is sprayed as an aerosol on the heated first precursor solution, or both the first precursor solution and the second precursor solution are sprayed on a heated solvent as aerosols, and the first precursor solution and the second precursor solution are reacted with each other to synthesize a core particle containing the different elements. The method for producing quantum dots, can suppress the non-uniformity of the particle size of the quantum dots and accompany increase in the distribution of emission wavelengths in large scale synthesis.

The present invention is directed to methods of preparing metal sulfide, metal selenide, or metal sulfide/selenide nanoparticles and the products derived therefrom. In various embodiments, the nanoparticles are derived from the reaction between precursor metal salts and certain sulfur- and/or selenium-containing precursors each independently having a structure of Formula (I), (II), or (III), or an isomer, salt, or tautomer thereof, where Q.sup.1,Q.sup.2,Q.sup.3,R.sup.1,R.sup.2,R.sup.3,R.sup.5, and X are defined within the specification.

The present invention is directed to methods of preparing metal sulfide, metal selenide, or metal sulfide/selenide nanoparticles and the products derived therefrom. In various embodiments, the nanoparticles are derived from the reaction between precursor metal salts and certain sulfur- and/or selenium-containing precursors each independently having a structure of Formula (I), (II), or (III), or an isomer, salt, or tautomer thereof, where Q.sup.1,Q.sup.2,Q.sup.3,R.sup.1,R.sup.2,R.sup.3,R.sup.5, and X are defined within the specification.

Provided are nanoparticles passivated with a cationic metal-chalcogenide complex (MCC) and a method of preparing the same. A passivated nanoparticle includes: a core nanoparticle; and a cationic metal-chalcogenide compound (MCC) fixed on a surface of the core nanoparticle.

The present invention seeks to provide cadmium-free quantum dots with a narrow fluorescence FWHM. The quantum dot does not contain cadmium and its fluorescence FWHM is 30 nm or less. The quantum dot is preferably a nanocrystal containing zinc and tellurium or zinc and tellurium and sulfur or zinc and tellurium and selenium and sulfur. Further, the quantum dot preferably has a core-shell structure in which the nanocrystal serves as a core and the surface of the core is coated with a shell.