A device including an LED light source optically coupled to a phosphor material including a green-emitting phosphor selected from the group consisting of compositions (A1)-(A62) and combinations thereof.

The present invention discloses a process for the preparation of metal sulphide quantum dots by using a very low cost sulphur precursor as a sulphur source. The metal sulphide quantum dots finds application in optical devices selected from photovoltaic cells, photodetectors and light-emission devices.

Methods of synthesizing transition metal dichalcogenide nanoparticles include forming a metal-amine complex, combining the metal-amine complex with a chalcogen source in at least one solvent to form a solution, heating the solution to a first temperature for a first period of time, and heating the solution to a second temperature that is higher than the first temperature for a second period of time.

Methods of synthesizing transition metal dichalcogenide nanoparticles include forming a metal-amine complex, combining the metal-amine complex with a chalcogen source in at least one solvent to form a solution, heating the solution to a first temperature for a first period of time, and heating the solution to a second temperature that is higher than the first temperature for a second period of time.

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 exemplary light emitting device includes an excitation source operable to generate excitation light with a dominant wavelength in a range 450 nm to 470 nm; a red photoluminescence material which generates light with a peak emission wavelength in a range 600 nm to 620 nm with a full width at half maximum emission intensity greater than 70 nm and less than 80 nm; a yellow to green photoluminescence material which generates light with a peak emission wavelength in a range 530 nm to 550 nm; and a narrow-band red photoluminescence material which generates light with a peak emission wavelength in a range 625 nm to 635 nm with a full width at half maximum emission intensity greater than about 5 nm and less than about 25 nm.

The present invention discloses a process for the preparation of metal sulphide quantum dots by using a very low cost sulphur precursor as a sulphur source. The metal sulphide quantum dots finds application in optical devices selected from photovoltaic cells, photodetectors and light-emission devices.

A exemplary light emitting device includes an excitation source operable to generate excitation light with a dominant wavelength in a range 450 nm to 470 nm; a red photoluminescence material which generates light with a peak emission wavelength in a range 600 nm to 620 nm with a full width at half maximum emission intensity greater than 70 nm and less than 80 nm; a yellow to green photoluminescence material which generates light with a peak emission wavelength in a range 530 nm to 550 nm; and a narrow-band red photoluminescence material which generates light with a peak emission wavelength in a range 625 nm to 635 nm with a full width at half maximum emission intensity greater than about 5 nm and less than about 25 nm.

A device including an LED light source optically coupled to a phosphor material including a green-emitting phosphor selected from the group consisting of compositions (A1)-(A62) and combinations thereof.

A phosphor which comprises a crystal phase that has a composition represented by the following formula [1]; and a light emitting device which is provided with this phosphor.

##STR00001## (MA includes one or more elements selected from the group consisting of Ca, Ba, Na, K, Y, Gd, and La, MB includes one or more elements selected from the group consisting of Li, Mg, and Zn, MC includes one or more elements selected from the group consisting of Al, Si, Ga, In, and Sc, X includes one or more elements selected from the group consisting of F, Cl, Br, and I, Re includes one or more elements selected from the group consisting of Eu, Ce, Pr, Tb, and Dy, and a, b, c, d, e, f, x, and y respectively satisfy the following expressions.

[00001]$0.8?a?1.2$$1.4?b?2.6$$1.4?c?2.6$$1.1?d?2.9$$1.1?e?2.9$$0.?f?0.1$$0.<x?0.2$$0.<y?0.7)$