Light-emitting device and light-emitting apparatus

A light-emitting device comprising:

• a photoluminescent layer that has a first surface perpendicular to a thickness direction thereof and emits light containing first light, an area of the first surface being larger than a sectional area of the photoluminescent layer perpendicular to the first surface;
• a light-transmissive layer having a higher refractive index than the photoluminescent layer;
• and
• one or more reflectors that are located directly on at least one of the photoluminescent layer and the light-transmissive layer, and at least partially surround the submicron structure, wherein
• the light-transmissive layer has a submicron structure comprising a periodic structure having at least projections or recesses arranged perpendicular to a thickness direction,
• at least one of the photoluminescent layer and the light-transmissive layer has a light emitting surface perpendicular to the thickness direction of the photoluminescent layer, the first light being emitted from the light emitting surface,
• the periodic structure satisfies the following relationship:
• λa/nwav-a<pa<λa
• where pa is the period of the periodic structure, λa is the wavelength of the first light in air, and nwav-a is the refractive index of the photoluminescent layer for the first light, and
• a thickness of the photoluminescent layer, the refractive index of the photoluminescent layer and the period of the periodic structure are set to limit a directional angle of the first light emitted from the light emitting surface.

A light-emitting device comprising:

• a light-transmissive layer having a submicron structure;
• a photoluminescent layer that has a first surface perpendicular to a thickness direction thereof and is located on the submicron structure and emits light containing first light;
• and
• one or more reflectors that are located directly on the light-transmissive layer and, at least partially surround the submicron structure, wherein
• at least one of the photoluminescent layer and the light-transmissive layer has a light emitting surface perpendicular to a thickness direction of the photoluminescent layer, the first light being emitted from the light emitting surface,
• the submicron structure comprises a periodic structure having at least projections or recesses arranged perpendicular to the thickness direction,
• the periodic structure satisfies the following relationship:
• λa/nwav-a<pa<λa
• where pa is the period of the periodic structure, λa is the wavelength of the first light in air, and nwav-a is the refractive index of the photoluminescent layer for the first light, and
• a thickness of the photoluminescent layer, the refractive index of the photoluminescent layer and the period of the periodic structure are set to limit a directional angle of the first light emitted from the light emitting surface.

A light-emitting device comprising:

• a photoluminescent layer that has a first surface perpendicular to a thickness direction thereof and emits light containing first light, an area of the first surface being larger than a sectional area of the photoluminescent layer perpendicular to the first surface;
• and
• one or more reflectors that are located directly on the photoluminescent layer, and at least partially surround the submicron structure, wherein
• the photoluminescent layer has a submicron structure comprising a periodic structure having at least projections or recesses arranged perpendicular to a thickness direction of the photoluminescent layer,
• the photoluminescent layer has a light emitting surface perpendicular to the thickness direction of the photoluminescent layer, the first light being emitted from the light emitting surface,
• the periodic structure satisfies the following relationship:
• λa/nwav-a<pa<λa
• where pa is the period of the periodic structure, λa is the wavelength of the first light in air, and nwav-a is the refractive index of the photoluminescent layer for the first light, and
• a thickness of the photoluminescent layer, the refractive index of the photoluminescent layer and the period of the periodic structure are set to limit a directional angle of the first light emitted from the light emitting surface.

A light-emitting device comprising:

• a photoluminescent layer that has a first surface perpendicular to a thickness direction thereof and emits light containing first light, an area of the first surface being larger than a sectional area of the photoluminescent layer perpendicular to the first surface;
• and
• a light-transmissive layer that is located on the photoluminescent layer, wherein
• at least one of the photoluminescent layer and the light-transmissive layer has a submicron structure comprising at least projections or recesses arranged perpendicular to a thickness direction of the photoluminescent layer, and one or more distributed Bragg reflectors comprising at least projections or recesses arranged perpendicular to the thickness direction of the photoluminescent layer,
• the one or more distributed Bragg reflectors at least partially surround the submicron structure,
• at least one of the photoluminescent layer and the light-transmissive layer has a light emitting surface perpendicular to the thickness direction of the photoluminescent layer, the first light being emitted from the light emitting surface, and
• the submicron structure satisfies the following relationship:
• λa/nwav-a<Dint<λa
• where Dint is a center-to-center distance between adjacent projections or recesses, λa is the wavelength of the first light in air, and nwav-a is the refractive index of the photoluminescent layer for the first light.