A quantum dot includes: a core including at least one first positive ion precursor and at least one negative ion precursor; a shell including at least one second positive ion precursor and at least one negative ion precursor and wrapping the core; and a ligand formed on a surface of the shell, wherein the first positive ion precursor is an n-period element and the second positive ion precursor is an (n-1)-period element, where n is an integer of 3 to 6.

A novel near-IR emitting cationic silver chalcogenide quantum dot with a mixed coating wherein the coating comprises of at least 2 different types of materials and is capable of luminescence at the desired near IR bandwidth at wavelengths of 800-850 nm. The quantum dot is fabricated via an advantageous single-step, homogeneous, aqueous method at a low temperature resulting a near IR emitting semiconductor quantum dot with high Quantum Yield, high transfection with low toxicity. The quantum dots may be used in medical imaging, tumor detection, drug delivery and labeling as well as in quantum dot sensitized solar cells.

A copper dopant delivery powder comprising a fused silica powder and a Cu.sub.2S powder. A method of making the copper dopant delivery powder. A method of making a copper-doped glass comprising placing a target glass in a container, packing a composite SiO.CuS dopant powder around the target glass and heating the container and SiO.CuS dopant powder to a temperature of between 800 C. and 1150 C. A copper-doped glass comprising a glass comprising copper-doping wherein the copper-doped glass was formed by covering the glass with a fused silica powder and a Cu.sub.2S powder, wherein the fused silica powder and the Cu.sub.2S powder are mixed in varying ratios of Cu.sub.2S to silica represented by the formula (SiO.sub.2).sub.(1-x)(Cu.sub.2S).sub.x and heating to a temperature of between 800 C. and 1150 C.

Embodiments of the present disclosure provide for methods of making quantum dots (QDs) (passivated or unpassivated) using a continuous flow process, systems for making QDs using a continuous flow process, and the like. In one or more embodiments, the QDs produced using embodiments of the present disclosure can be used in solar photovoltaic cells, bio-imaging, IR emitters, or LEDs.

A method of manufacturing a quantum dot, the method including preparing a CdS/CdSe/CdS quantum dot that includes a CdS-containing first core, a CdSe-containing second core, and a CdS-containing shell; forming a Cu.sub.2S/Cu.sub.2Se/Cu.sub.2S quantum dot by injecting the CdS/CdSe/CdS quantum dot into a solution containing a Cu precursor; and forming a ZnS/ZnSe/ZnS quantum dot by injecting the Cu.sub.2S/Cu.sub.2Se/Cu.sub.2S quantum dot into a solution containing a Zn precursor.

A method for producing a quantum dot that 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 including a core represented by Formula 1, a method of manufacturing the quantum dot, and a light-emitting device and an apparatus including the quantum dot are provided:

M.sup.1.sub.aM.sup.2.sub.bM.sup.3.sub.cM.sup.4.sub.dM.sup.5.sub.e,Formula 1 wherein M.sup.1 is a Group I metal element, M.sup.2 and M.sup.3 are each independently a Group III metal element, and M.sup.4 and M.sup.5 are each independently a Group VI element; and a is 0.05 to 0.60, b is 0 to 1.4, c is 0 to 1.4, d is 0 to 2.0, and e is 0 to 2.0.

A method of synthesis of two-dimensional (2D) nanoparticles comprises combining a first nanoparticle precursor and a second nanoparticle precursor in one or more solvents to form a solution, followed by heating the solution to a first temperature for a first time period, then subsequently heating the solution to a second temperature for a second time period, wherein the second temperature is higher than the first temperature, to effect the conversion of the nanoparticle precursors into 2D nanoparticles. In one embodiment, the first nanoparticle precursor is a metal-amine complex and the second nanoparticle precursor is a slow-releasing chalcogen source.

A novel near-IR emitting cationic silver chalcogenide quantum dot with a mixed coating wherein the coating comprises of at least 2 different types of materials and is capable of luminescence at the desired near IR bandwidth at wavelengths of 800-850 nm. The quantum dot is fabricated via an advantageous single-step, homogeneous, aqueous method at a low temperature resulting a near IR emitting semiconductor quantum dot with high Quantum Yield, high transfection with low toxicity. The quantum dots may be used in medical imaging, tumor detection, drug delivery and labeling as well as in quantum dot sensitized solar cells.

There is provided a dispersion liquid containing a quantum dot having a band gap of 1.35 eV or less, two or more kinds of ligands, and a solvent, in which at least one of the two or more kinds of ligands is a ligand having a boiling point of 200 C. or lower. There are also provided manufacturing methods for a quantum dot film using a dispersion liquid, a photodetection element, and an image sensor.