A nanocomposite includes: a matrix phase; and a functional area disposed in the matrix phase. The functional area contains monocrystal fine particles.

A method of making a nanocrystal includes slowly infusing a M-containing compound and a X donor into a mixture including a nanocrystal core, thereby forming an overcoating including M and X on the core.

Light emitting devices and LED-filaments comprise an excitation source (e.g. LED) and a photoluminescence material comprising a combination of a first narrow-band red photoluminescence material which generates light with a peak emission wavelength in a range 580 nm to 628 nm and a full width at half maximum emission intensity in a range 45 nm to 60 nm and a second narrow-band red photoluminescence material generates light with a peak emission wavelength in a range 628 nm to 640 nm and a full width at half maximum emission intensity in a range 5 nm to 20 nm. At least one of the first and second narrow-band red photoluminescence materials can comprise a narrow-band red phosphor or a quantum dot (QD) material.

A quantum dot having a perovskite crystal structure and including a compound represented by Chemical Formula 1:

ABX.sub.3+Chemical Formula 1 wherein, A is a Group IA metal selected from Rb, Cs, Fr, and a combination thereof, B is a Group IVA metal selected from Si, Ge, Sn, Pb, and a combination thereof, X is a halogen selected from F, Cl, Br, and I, BR.sub.4, or a combination thereof, and is greater than 0 and less than or equal to about 3; and wherein the quantum dot has a size of about 1 nanometer to about 50 nanometers

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 quantum dot includes a nanocrystalline core and a nanocrystalline shell. The nanocrystalline core includes a core body and a doping material that is non-uniformly doped in the core body. The core body has a sphalerite-type crystal structure, and includes at least one element from Group IB, at least one element from Group IIIA and at least one element from Group VIA. The doping material includes at least one doping element selected from the group consisting of an element from Group IB, an element from Group IIB and an element from Group IIIA. The nanocrystalline shell surrounds the nanocrystalline core and includes at least one element from Group VIA, and at least one element from one of Group IIB and Group IIIA. A method for preparing the quantum dot is also disclosed.

A quantum dot having a perovskite crystal structure and including a compound represented by Chemical Formula 1:
ABX.sub.3+Chemical Formula 1
wherein, A is a Group IA metal selected from Rb, Cs, Fr, and a combination thereof, B is a Group IVA metal selected from Si, Ge, Sn, Pb, and a combination thereof, X is a halogen selected from F, Cl, Br, and I, BF.sub.4, or a combination thereof, and is greater than 0 and less than or equal to about 3; and wherein the quantum dot has a size of about 1 nanometer to about 50 nanometers.

Composite nanoparticle compositions and associated nanoparticle assemblies are described herein which, in some embodiments, exhibit enhancements to one or more thermoelectric properties including increases in electrical conductivity and/or Seebeck coefficient and/or decreases in thermal conductivity. In one aspect, a composite nanoparticle composition comprises a semiconductor nanoparticle including a front face and a back face and sidewalls extending between the front and back faces. Metallic nanoparticles are bonded to at least one of the sidewalls establishing a metal-semiconductor junction.

Disclosed are quantum dots based on a graded multishell structure and a method of manufacturing the same. More particularly, each of the quantum dots according to an embodiment of the present invention includes a core, inter shells surrounding the core, and an outer shell surrounding the inter shells, wherein the concentrations of compounds composing the inter shells are changed stepwise from the core to the outer shell.

An object of the present invention is to provide a method for manufacturing quantum dots capable of containing a large amount of Zn on a surface thereof, and a quantum dot. A method for manufacturing quantum dots of the present invention includes a step of producing a core containing at least Ag, Ga, and S or Ag, Ga, and Se, and a step of coating a surface of the core with a shell, and in the step of coating with the shell, the surface of the core is coated with GaS, and then Zn is added. It is preferable that the surface of the core is coated with ZnS after being coated with GaS. It is preferable that the core and the shell do not contain Cd and In.