A phosphor particle for a micro LED or a mini LED, consisting of CASN and/or SCASN. A cured sheet produced by the following sheet producing procedure using this phosphor particle satisfies the following optical characteristics.

<Sheet Producing Procedure>

(1) 40 parts by mass of the phosphor particle and 60 parts by mass of a silicone resin OE-6630 manufactured by Dow Corning Toray Co., Ltd. are subjected to a stirring treatment and a defoaming treatment using a rotation and revolution mixer to obtain a uniform mixture.

(2) The mixture obtained in the section (1) is added dropwise to a first transparent fluororesin film, and a second transparent fluororesin film is further laminated on the dropped material to obtain a sheet-like material. This sheet-like material is molded into an uncured sheet using a roller having a gap in which 50 μm is added to a total thickness of the first fluororesin film and the second fluororesin film.

(3) The uncured sheet obtained in the section (2) is heated under conditions of 150° C. and 60 minutes. Then, the first fluororesin film and the second fluororesin film are peeled off to obtain a cured sheet having a film thickness of 50±5 μm.

<Optical Characteristics>

When an intensity at a peak wavelength of blue light emitted from a blue LED having a peak wavelength in a range of 450 nm to 460 nm is defined as Ii [W/nm], and in a case where the blue light is emitted to one surface side of the cured sheet, when an intensity of light emitted from another surface side of the cured sheet at a peak wavelength in a range of 450 nm to 460 nm is defined as It [W/nm] and an intensity thereof at a peak wavelength in a range of 600 nm to 650 nm is defined as Ip [W/nm], It/Ii is equal to or less than 0.2 and Ip/Ii is equal to or more than 0.05.

The present invention discloses a nitrogen-containing luminescent particle, characterized in that a structure of the nitrogen-containing luminescent particle is divided into an oxygen poor zone, a transition zone, and an oxygen rich zone from a core to an outer surface of the particle depending on an increasing oxygen content, the oxygen poor zone being predominantly a nitride luminescent crystal or oxygen-containing solid solution thereof, the transition zone being predominantly a nitroxide material, the oxygen rich zone being predominantly an oxide material or oxynitride material; the nitride luminescent crystal or oxygen-containing solid solution thereof has a chemical formula of M.sub.m-m1A.sub.a1B.sub.b1O.sub.o1N.sub.n1:R.sub.m1, the nitroxide material has a chemical formula of M.sub.m-m2A.sub.a2B.sub.b2O.sub.o2N.sub.n2:R.sub.m2, the oxide material or oxynitride material has a chemical formula of M.sub.m-m3A.sub.a3B.sub.b3O.sub.o3N.sub.n3:R.sub.m3. The nitrogen-containing luminescent particle and the nitrogen-containing illuminant of the present invention have good chemical stability, good aging and light decay resistance, and high luminescent efficiency, and are useful for various luminescent devices. The manufacturing method of the present invention is easy and reliable, and useful for industrial mass production.

The present invention discloses a nitrogen-containing luminescent particle, characterized in that a structure of the nitrogen-containing luminescent particle is divided into an oxygen poor zone, a transition zone, and an oxygen rich zone from a core to an outer surface of the particle depending on an increasing oxygen content, the oxygen poor zone being predominantly a nitride luminescent crystal or oxygen-containing solid solution thereof, the transition zone being predominantly a nitroxide material, the oxygen rich zone being predominantly an oxide material or oxynitride material; the nitride luminescent crystal or oxygen-containing solid solution thereof has a chemical formula of M.sub.m-m1A.sub.a1B.sub.b1O.sub.o1N.sub.n1:R.sub.m1, the nitroxide material has a chemical formula of M.sub.m-m2A.sub.a2B.sub.b2O.sub.o2N.sub.n2:R.sub.m2, the oxide material or oxynitride material has a chemical formula of M.sub.m-m3A.sub.a3B.sub.b3O.sub.o3N.sub.n3:R.sub.m3. The nitrogen-containing luminescent particle and the nitrogen-containing illuminant of the present invention have good chemical stability, good aging and light decay resistance, and high luminescent efficiency, and are useful for various luminescent devices. The manufacturing method of the present invention is easy and reliable, and useful for industrial mass production.

A phosphor includes, as a main component, a compound represented by a general formula (3-a)YO.sub.3/2.aCeO.sub.3/2.(5-b)AlO.sub.3/2.bGaO.sub.3/2.cKO.sub.1/2.dPO.sub.5/2, where a, b, c and d satisfy 0.12≦a≦0.18, 1.50≦b≦3.00, 0.01≦c≦0.08, and 0.01≦d≦0.08.

A light-emitting device and an electronic apparatus including the light-emitting device are provided. The light-emitting device includes a first electrode, a second electrode facing the first electrode, and an interlayer between the first electrode and the second electrode. The interlayer includes an emission layer, a hole transport region between the first electrode and the emission layer, and an electron transport region between the emission layer and the second electrode. The emission layer includes a first quantum dot, the hole transport region includes a second quantum dot, and the electron transport region includes a third quantum dot. The first quantum dot to the third quantum dot may be understood by referring to the description of the first quantum dot to the third quantum dot provided herein.

A light-emitting device and an electronic apparatus including the light-emitting device are provided. The light-emitting device includes a first electrode, a second electrode facing the first electrode, and an interlayer between the first electrode and the second electrode. The interlayer includes an emission layer, a hole transport region between the first electrode and the emission layer, and an electron transport region between the emission layer and the second electrode. The emission layer includes a first quantum dot, the hole transport region includes a second quantum dot, and the electron transport region includes a third quantum dot. The first quantum dot to the third quantum dot may be understood by referring to the description of the first quantum dot to the third quantum dot provided herein.

Provided is a method for producing a phosphor, using a nitride raw material, that gives a high-reliability (Sr,Ca)AlSiN.sub.3-based nitride phosphor at a productivity higher than before. The method comprises a mixing step of mixing raw materials and a calcining step of calcining the mixture obtained in the mixing step and, in producing the phosphor having a crystalline structure substantially identical with that of (Sr,Ca)AlSiN.sub.3 crystal as the host crystal, a strontium nitride containing SrN, Sr.sub.2N, or the mixture thereof as the main crystalline phase, as determined by crystalline phase analysis by powder X-ray diffractometry, and having a nitrogen content of 5 to 12 mass % is used as part of the raw materials.

Quantum dot semiconductor nanoparticle compositions that incorporate ions such as zinc, aluminum, calcium, or magnesium into the quantum dot core have been found to be more stable to Ostwald ripening. A core-shell quantum dot may have a core of a semiconductor material that includes indium, magnesium, and phosphorus ions. Ions such as zinc, calcium, and/or aluminum may be included in addition to, or in place of, magnesium. The core may further include other ions, such as selenium, and/or sulfur. The core may be coated with one (or more) shells of semiconductor material. Example shell semiconductor materials include semiconductors containing zinc, sulfur, selenium, iron and/or oxygen ions.

Quantum dot semiconductor nanoparticle compositions that incorporate ions such as zinc, aluminum, calcium, or magnesium into the quantum dot core have been found to be more stable to Ostwald ripening. A core-shell quantum dot may have a core of a semiconductor material that includes indium, magnesium, and phosphorus ions. Ions such as zinc, calcium, and/or aluminum may be included in addition to, or in place of, magnesium. The core may further include other ions, such as selenium, and/or sulfur. The core may be coated with one (or more) shells of semiconductor material. Example shell semiconductor materials include semiconductors containing zinc, sulfur, selenium, iron and/or oxygen ions.

Quantum dots that are cadmium-free and/or stoichiometncally tuned are disclosed, as are methods of making them. Inclusion of the quantum dots and others in a stabilizing polymer matrix is also disclosed. The polymers are chosen for their strong binding affinity to the outer layers of the quantum dots such that the bond dissociation energy between the polymer material and the quantum dot is greater than the energy required to reach the melt temperature of the cross-linked polymer.