To provide an illumination method and a light-emitting device which are capable of achieving, under an indoor illumination environment where illuminance is around 5000 lx or lower when performing detailed work and generally around 1500 lx or lower, a color appearance or an object appearance as perceived by a person, will be as natural, vivid, highly visible, and comfortable as though perceived outdoors in a high-illuminance environment, regardless of scores of various color rendition metric. Light emitted from the light-emitting device illuminates an object such that light measured at a position of the object satisfies specific requirements. A feature of the light-emitting device is that light emitted by the light-emitting device in a main radiant direction satisfies specific requirements.

Devices, systems, and methods for providing wireless personal area networks (PANs) and local area networks (LANs) using visible and near-visible optical spectrum. Various constructions and material selections are provided herein. According to one embodiment, a free space optical (FSO) communication apparatus includes a digital data port, an array of light-emitting diodes (LEDs) each configured to have a transient response time of less than 500 picoseconds (ps), and current drive circuitry coupled between the digital data port and the array of LEDs.

Provided is an imaging element including a photoelectric conversion unit formed by stacking a first electrode, a photoelectric conversion layer and a second electrode. The photoelectric conversion unit further includes a charge storage electrode which is disposed to be spaced apart from the first electrode and disposed opposite to the photoelectric conversion layer via an insulating layer. The photoelectric conversion unit is formed of N number of photoelectric conversion unit segments, and the same applies to the photoelectric conversion layer, the insulating layer and the charge storage electrode. An n.sup.th photoelectric conversion unit segment is formed of an n.sup.th charge storage electrode segment, an n.sup.th insulating layer segment and an n.sup.th photoelectric conversion layer segment. As n increases, the n.sup.th photoelectric conversion unit segment is located farther from the first electrode. A thickness of the insulating layer segment gradually changes from a first to N.sup.th photoelectric conversion unit segment.

Various forms of Mg.sub.a(Si.sub.x(Ge.sub.ySn.sub.1-y).sub.1-x)O.sub.b are disclosed. In some aspects, an epitaxial layer comprises single crystal Mg.sub.a(Si.sub.x(Ge.sub.ySn.sub.1-y).sub.1-x)O.sub.b, wherein 1.5a2.5, 3b5, 0x1, and 0y1; wherein the single crystal Mg.sub.a(Si.sub.x(Ge.sub.ySn.sub.1-y).sub.1-x)O.sub.b has a crystal symmetry compatible with a substrate or an underlying layer on which the single crystal Mg.sub.a(Si.sub.x(Ge.sub.ySn.sub.1-y).sub.1-x)O.sub.b is grown. In some aspects, a semiconductor structure includes an epitaxial layer comprising single crystal Mg.sub.a(Si.sub.x(Ge.sub.ySn.sub.1-y).sub.1-x)O.sub.b, wherein 1.5a2.5, 3b5, 0x1, and 0y1; The semiconductor structure also includes a substrate or an underlying layer on which the single crystal Mg.sub.a(Si.sub.x(Ge.sub.ySn.sub.1-y).sub.1-x)O.sub.b is grown; wherein the single crystal Mg.sub.a(Si.sub.x(Ge.sub.ySn.sub.1-y).sub.1-x)O.sub.b has a crystal symmetry compatible with the substrate or the underlying layer.

Various forms of Mg.sub.a(Si.sub.x(Ge.sub.ySn.sub.1-y).sub.1-x)O.sub.b are disclosed. In some aspects, an epitaxial layer comprises single crystal Mg.sub.a(Si.sub.x(Ge.sub.ySn.sub.1-y).sub.1-x)O.sub.b, wherein 1.5a2.5, 3b5, 0x1, and 0y1; wherein the single crystal Mg.sub.a(Si.sub.x(Ge.sub.ySn.sub.1-y).sub.1-x)O.sub.b has a crystal symmetry compatible with a substrate or an underlying layer on which the single crystal Mg.sub.a(Si.sub.x(Ge.sub.ySn.sub.1-y).sub.1-x)O.sub.b is grown. In some aspects, a semiconductor structure includes an epitaxial layer comprising single crystal Mg.sub.a(Si.sub.x(Ge.sub.ySn.sub.1-y).sub.1-x)O.sub.b, wherein 1.5a2.5, 3b5, 0x1, and 0y1; The semiconductor structure also includes a substrate or an underlying layer on which the single crystal Mg.sub.a(Si.sub.x(Ge.sub.ySn.sub.1-y).sub.1-x)O.sub.b is grown; wherein the single crystal Mg.sub.a(Si.sub.x(Ge.sub.ySn.sub.1-y).sub.1-x)O.sub.b has a crystal symmetry compatible with the substrate or the underlying layer.

A method for producing a semiconductor nanoparticle, a semiconductor nanoparticle, an electroluminescent device including the semiconductor nanoparticle, and a display device. In an embodiment, the method of an embodiment includes preparing a first semiconductor nanocrystal including zinc, tellurium, and selenium, wherein the preparing of the first semiconductor nanocrystal includes heating a first solution including a first zinc precursor, a first selenium precursor and a tellurium precursor in a first organic solvent at a reaction temperature to form a heated solution; and adding an additive to the heated first solution to produce the first semiconductor nanocrystal, wherein the additive includes a second selenium precursor and the additive does not include tellurium, and the semiconductor nanoparticle is configured to emit blue light.

A method for producing a semiconductor nanoparticle, a semiconductor nanoparticle, an electroluminescent device including the semiconductor nanoparticle, and a display device. In an embodiment, the method of an embodiment includes preparing a first semiconductor nanocrystal including zinc, tellurium, and selenium, wherein the preparing of the first semiconductor nanocrystal includes heating a first solution including a first zinc precursor, a first selenium precursor and a tellurium precursor in a first organic solvent at a reaction temperature to form a heated solution; and adding an additive to the heated first solution to produce the first semiconductor nanocrystal, wherein the additive includes a second selenium precursor and the additive does not include tellurium, and the semiconductor nanoparticle is configured to emit blue light.

An embodiment provides a semiconductor device package, the semiconductor device package comprising: a substrate including an electrode disposed on one surface; a metal sidewall disposed on the substrate while surrounding the electrode; a semiconductor device disposed on the electrode; and a light transmitting member disposed on the metal sidewall to cover the semiconductor device, wherein the metal sidewall has the inner surface and the outer surface which are corrugated, and includes: a first metal part disposed on the substrate; a second metal part disposed on the first metal part; and a third metal part disposed on the second metal part, and the inner surface or the outer surface of the metal sidewall includes a recess portion between the second metal part and the third metal part.

An embodiment provides a semiconductor device package, the semiconductor device package comprising: a substrate including an electrode disposed on one surface; a metal sidewall disposed on the substrate while surrounding the electrode; a semiconductor device disposed on the electrode; and a light transmitting member disposed on the metal sidewall to cover the semiconductor device, wherein the metal sidewall has the inner surface and the outer surface which are corrugated, and includes: a first metal part disposed on the substrate; a second metal part disposed on the first metal part; and a third metal part disposed on the second metal part, and the inner surface or the outer surface of the metal sidewall includes a recess portion between the second metal part and the third metal part.

A light source can include at least one light emitter and is configured to emit a first light during a region of a light period and emit both the first light and a second light of a different wavelength during a remaining region of the light period. The emitter can include semiconductor layers and an active layer configured to emit light having a specific wavelength due to a band gap difference in an energy band depending on a material used to form the active layer. A plant cultivation device can include the light source and a main body in which a plant can be grown. The light period can be configured to increase a content of an active ingredient in the plant. The first light can have a longer peak wavelength than a peak wavelength of the second light.