Provided is a light emitting device that includes a light emitting element having a light emission peak wavelength ranging from 380 nm to 490 nm, and a fluorescent material excited by light from the light emitting element and emitting light having at a light emission peak wavelength ranging from 580 nm or more to less than 680 nm. The light emitting device emits light having a ratio R/B of a photon flux density R to a photon flux density B ranging from 2.0 to 4.0 and a ratio R/FR of the photon flux density R to a photon flux density FR ranging from 0.7 to 13.0, the photon flux density R being in a wavelength range of 620 nm or more and less than 700 nm, the photon flux density B being in a wavelength range of 380 nm or more and 490 nm or less, and the photon flux density FR being in a wavelength range of 700 nm or more and 780 nm or less.

The invention provides a lighting device (10) comprising a light source (100) configured to generate light source light (101) and a light converter element (200), wherein the light converter element (200) comprises a light transmissive matrix (205), wherein the light transmissive matrix (205) comprises: (i) a first luminescent material (210) configured to convert at least part of one or more of (a) the light source light (101) and (b) optionally a second luminescent material light (221) from an optional second luminescent material (220) into a first luminescent material light (211); and (ii) a thermo-responsive liquid crystalline compound (250); wherein the light transmissive matrix (205) is configured in thermal contact with the light source (100), and wherein the lighting device (10) is further configured to provide lighting device light (11) comprising said light source light (101), said first luminescent material light (210) and optionally said second luminescent material light (221), and wherein said light converter element is arranged for changing one or more of the color and color temperature of the lighting device light with the electrical power provided to the light source.

To provide a quantum dot and manufacturing method of the dot particularly capable of reducing organic residues adhering to the quantum dot surface and of suppressing the black discoloration occurrence of a layer including the quantum dot positioned immediately above a light emitting device, and a compact, sheet member, wavelength conversion member and light emitting apparatus with high luminous efficiency using the quantum dot, a quantum dot of the present invention has a core portion including a semiconductor particle, and a shell portion with which the surface of the core portion is coated, and is characterized in that a weight reduction up to 490° C. is within 75% in a TG-DTA profile. Further, the quantum dot of the invention is characterized in that oleylamine (OLA) is not observed in GC-MS qualitative analysis at 350° C.

One embodiment of the present invention is a display device including a first insulating layer, a second insulating layer, a first transistor, a second transistor, a first light-emitting diode, a second light-emitting diode, and a color conversion layer. The first insulating layer is over the first transistor and the second transistor. The first light-emitting diode and the second light-emitting diode are over the first insulating layer. The color conversion layer is over the second light-emitting diode. The color conversion layer is configured to convert light emitted from the second light-emitting diode into a light having a longer wavelength. The first transistor and the second transistor each include a metal oxide layer and a gate electrode. The metal oxide layer includes a channel formation region. A top surface of the gate electrode is level or substantially level with a top surface of the second insulating layer.

One embodiment of the present invention is a display device including a first insulating layer, a second insulating layer, a first transistor, a second transistor, a first light-emitting diode, a second light-emitting diode, and a color conversion layer. The first insulating layer is over the first transistor and the second transistor. The first light-emitting diode and the second light-emitting diode are over the first insulating layer. The color conversion layer is over the second light-emitting diode. The color conversion layer is configured to convert light emitted from the second light-emitting diode into a light having a longer wavelength. The first transistor and the second transistor each include a metal oxide layer and a gate electrode. The metal oxide layer includes a channel formation region. A top surface of the gate electrode is level or substantially level with a top surface of the second insulating layer.

The present disclosure provides a LED package structure and a LED light-emitting device. The LED package structure comprises a LED chip and a wavelength converting layer covering the LED chip. The wavelength converting layer contains red phosphor, which has lower amount in edge portion than in center portion. It is possible to avoid direct or indirect excitation for generating red light in edge portion of the LED chip by adjusting the amount of red phosphor in edge portion to be lower, so that the color temperature in edge portion may be adjusted toward to high color temperature, and thus the phenomenon of yellow halo may be alleviated.

According to one embodiment, an illumination system includes a plurality of white light sources that satisfies −0.2≦[(P(λ)×V(λ))/(P(λmax1)×V(λmax1))−(B(λ)×V(λ))/(B(λmax2)×V(λmax2))]≦+0.2 where P(λ) is an emission spectrum of a white light source having a specific color temperature, B(λ) is an emission spectrum of black body radiation having a corresponding color temperature, V(λ) is a spectrum of spectral luminous efficiency, λmax1 is a wavelength at which P(λ)×V(λ) becomes maximum, and λmax2 is a wavelength at which B(λ)×V(λ) becomes maximum. The respective white light sources have different color temperatures, and light from the respective white light sources is irradiated from different directions to a target.

A light emitting device includes a light emitting element, a frame, a first light-transmissive member, and a second light-transmissive member. The light emitting element includes an element upper surface from which a light is configured to be emitted, an element bottom surface opposite to the element upper surface, and an element lateral surface connecting the element upper surface and the element bottom surface. The frame is provided to surround the light emitting element to be opposite to the element lateral surface. The first light-transmissive member is provided on the element upper surface and the element lateral surface to contact the frame. The first light-transmissive member covers the element upper surface and the element lateral surface. The second light-transmissive member is provided on the first light-transmissive member.

A light-emitting diode (LED) package includes a light-emitting structure, an optical wavelength conversion layer on the light-emitting structure, and an optical filter layer on the optical wavelength conversion layer. The light-emitting structure includes a first-conductivity-type semiconductor layer, an active layer on the first-conductivity-type semiconductor layer, and a second-conductivity-type semiconductor layer on the active layer, and emits first light having a first peak wavelength. The optical wavelength conversion layer absorbs the first light emitted from the light-emitting structure and emits second light having a second peak wavelength different from the first peak wavelength. The optical filter layer reflects the first light emitted from the light-emitting structure and transmits the second light emitted from the optical wavelength conversion layer.

A light-emitting diode (LED) package includes a light-emitting structure, an optical wavelength conversion layer on the light-emitting structure, and an optical filter layer on the optical wavelength conversion layer. The light-emitting structure includes a first-conductivity-type semiconductor layer, an active layer on the first-conductivity-type semiconductor layer, and a second-conductivity-type semiconductor layer on the active layer, and emits first light having a first peak wavelength. The optical wavelength conversion layer absorbs the first light emitted from the light-emitting structure and emits second light having a second peak wavelength different from the first peak wavelength. The optical filter layer reflects the first light emitted from the light-emitting structure and transmits the second light emitted from the optical wavelength conversion layer.