The present disclosure relates to semiconductor structures and, more particularly, to transistor with wrap-around extrinsic base and methods of manufacture. The structure includes: a substrate; a collector region within the substrate; an emitter region over the substrate and which comprises silicon based material; an intrinsic base; and an extrinsic base overlapping the emitter region and the intrinsic base; an extrinsic base overlapping the emitter region and the intrinsic base; and an inverted T shaped spacer which separates the emitter region from the extrinsic base and the collector region from the emitter region.

A wavelength converter including, as semiconductor nanoparticles, a first semiconductor nanoparticle that converts light with a wavelength of 450 nm into light with a wavelength .sub.1 nm, and a second semiconductor nanoparticle that converts light with a wavelength of 450 nm into light with a wavelength .sub.2 nm, in which the wavelength .sub.1 and the wavelength .sub.2 satisfy .sub.1>.sub.2>450, and a relation between an emission intensity I.sub.1b and an emission intensity I1a satisfies I.sub.1a<I.sub.1b, where I.sub.1b is an emission intensity at the wavelength .sub.1 when the wavelength converter including the first and second semiconductor nanoparticles is irradiated with light with a wavelength of 450 nm and an excitation photon number N.sub.0, and I.sub.1a is an emission intensity at the wavelength .sub.1 when a wavelength converter including only the first semiconductor nanoparticle is irradiated with the light with a wavelength of 450 nm and an excitation photon number N.sub.0.

Solid-state lighting devices including light-emitting diodes (LEDs) and more particularly arrangements of lumiphoric materials within LED chips are disclosed. Lumiphoric materials are incorporated or otherwise embedded within LED chips. Embedded lumiphoric materials are provided so that at least some portions of light generated by active LED structures are subject to wavelength conversion before exiting LED chip surfaces. Lumiphoric materials may form dielectric and/or passivation layers between various chip structures, such as between active LED structures and internal reflective layers and/or electrical contacts. Internally converted light propagating within LED chips may pass back through active LED structures with reduced light absorption.

An epitaxial structure includes a composite base unit and an emitter unit. The composite base unit includes a first base layer and a second base layer formed on the first base layer. The first base layer is made of a material of In.sub.xGa.sub.(1-x)As.sub.(1-y)N.sub.y, in which 0<x0.2, and 0y0.035, and when y is not 0, x=3y. The second base layer is made of a material In.sub.mGa.sub.(1-m)As, in which 0.03m0.2. The emitter unit is formed on the second base layer 12 opposite to the first base layer 11, and is made of an indium gallium phosphide-based material. A transistor including the epitaxial structure is also disclosed.

A light-emitting diode 100 includes a first region 1, for example of the P type, formed in a first layer 10 and forming, in a direction normal to a basal plane, a stack with a second region 2 having at least one quantum well formed in a second layer 20, and including a third region 3, for example of the N type, extending in the direction normal to the plane, bordering and in contact with the first and second regions 1, 2, through the first and second layers 10, 20. A process for producing a light-emitting diode 100 in which the third region 3 is formed by implantation into and through the first and second layers 10, 20.

A light emitting device comprises a light emitting element having a light emission peak wavelength in a range of 400 nm or more and 490 nm or less and a first fluorescent material having a light emission peak wavelength in a range of 570 nm or more and 680 nm or less, and emits light having a correlated color temperature being 1,950 K or less, an average color rendering index Ra being 70 or more, a full width at half maximum of a light emission peak having the maximum light emission intensity being 110 nm or less, and a ratio B/L of an effective radiance B to a luminance L being 0.151 or less, wherein the luminance of light emitted by the light emitting device in a range of 300 nm or more and 800 nm or less when B and L is as defined in the disclosure.

Provided is a light-emitting device, a lighting appliance, and a street light that emit light with minimal negative effects on the behavior of sea turtles and which makes irradiated objects easily visible to humans. The light-emitting device includes a light-emitting element having an emission peak wavelength within a range from 400 nm to 490 nm; and a first phosphor having an emission peak wavelength within a range from 570 nm to 680 nm, wherein the light-emitting device, lighting appliance, and street light emit light that has a correlated color temperature of 1950 K or less, an average color rendering index Ra of 40 or greater, a full width at half maximum of an emission spectrum indicating a maximum emission intensity in an emission spectrum of the light-emitting device of 110 nm or less, and a sea turtle light attraction index T derived from Equation (1) of 0.416 or less.

According to an aspect of the present disclosure, there is provided a fluorescent substance powder containing a plurality of CASN-based fluorescent substance particles. Average circularity of fluorescent substance particles having a particle size of 1 m or greater among the CASN-based fluorescent substance particles is 0.820 or greater, and a standard deviation of the circularity is less than 0.080.

A light emitting device includes a light emitting diode chip configured to emit first light having a peak wavelength of 400 nm to 470 nm; a wavelength conversion material converting a portion of the first light into second light having a peak wavelength of 620 nm to 670 nm; and a near-infrared phosphor configured to convert a portion of the first light into third light having a peak wavelength of 740 nm to 820 nm, wherein the near-infrared phosphor includes a phosphor represented by composition formula CaAl.sub.(12-x-y)Ga.sub.yO.sub.19:xCr.sup.3+, where x satisfies 0.1x0.3 and y satisfies 1 or more, and an emission spectrum of the third light alone has a ratio of an intensity of 690 nm relative to an intensity of 780 nm of 0.3 or less.

Disclosed are a semiconductor structure, a manufacturing method of a semiconductor structure, and a light-emitting device. The semiconductor structure includes: a light-emitting structure including a plurality of light-emitting units, where an insulating structure is disposed between adjacent two light-emitting units; and a light-control layer, disposed on a side of the light-emitting structure, including a plurality of light-control regions regularly disposed and a substrate structure disposed between adjacent two light-control regions, one light-control region corresponding to at least one light-emitting unit, where the substrate structure includes a growth substrate layer structure and an etching stop layer structure stacked along a direction away from the light-emitting structure.