LIGHT-EMITTING STRUCTURE AND LIGHT-EMITTING MODULE
A light-emitting structure includes a substrate, a light-emitting device, a light reflective layer, and a reflective microstructure. The light-emitting device, which includes a top surface and side surfaces, is disposed on the substrate. The light reflective layer is disposed above the top surface of the light-emitting device to reflect a portion of the light being emitted from the top surface of the light-emitting device towards the side surfaces of the light-emitting device. The reflective microstructure is disposed on the substrate and surrounding the side surfaces of the light-emitting device to reflect the light being emitted from the side surfaces of the light-emitting device.
1 . A light-emitting structure, comprising:
a substrate;
a light-emitting device disposed on the substrate, and the light-emitting device comprising a top surface and side surfaces;
a light reflective layer disposed above the top surface of the light-emitting device for reflecting a portion of light emitted from the top surface of the light-emitting device to the side surfaces of the light-emitting device; and
a reflective microstructure disposed on the substrate and surrounding the side surfaces of the light-emitting device for reflecting light emitted from the side surfaces of the light-emitting device.
2 . The light-emitting structure of claim 1 , wherein the reflective microstructure has a jagged shape in a cross-sectional view.
3 . The light-emitting structure of claim 1 , wherein the reflective microstructure further comprises:
a plurality of concentric structures, each having an inclined surface facing the light-emitting device; and
a reflective layer disposed on the inclined surfaces of the concentric structures.
4 . The light-emitting structure of claim 3 , wherein a reflectivity of the reflective layer for a light-emitting wavelength of the light-emitting device is greater than 96%.
5 . The light-emitting structure of claim 4 , wherein the reflective layer comprises metal, or a polymer material doped with reflective particles.
6 . The light-emitting structure of claim 3 , wherein an angle between the inclined surface of the concentric structures and an upper surface of the substrate is 10 degrees to 30 degrees.
7 . The light-emitting structure of claim 6 , wherein each of the inclined surfaces of the concentric structures has a different angle with the substrate.
8 . The light-emitting structure of claim 3 , wherein a ratio of a maximum height of the concentric structures to a height of the light-emitting device is less than ⅓.
9 . The light-emitting structure of claim 3 , wherein the concentric structures are concentric circles, concentric triangles, concentric squares, or concentric polygons in a top view.
10 . The light-emitting structure of claim 3 , wherein each of the concentric structures has a same height.
11 . The light-emitting structure of claim 3 , wherein a pitch between adjacent ones of the inclined surface of the concentric structures is 0.1 mm to 1 mm.
12 . The light-emitting structure of claim 3 , wherein the concentric structures are composed of discrete line segments in the top view.
13 . The light-emitting structure of claim 1 , wherein the reflective microstructure is made of PET, UV resin, PMMA, PC, silicone, or a combination thereof.
14 . The light-emitting structure of claim 1 , wherein the light reflective layer comprises a distributed Bragg reflection (DBR) mirror, metal or a resin mixed reflective metal oxide particles.
15 . The light-emitting structure of claim 1 , wherein the light-emitting device comprises a light-emitting diode, and the light reflective layer is disposed on a top surface of the light-emitting diode.
16 . The light-emitting structure of claim 15 , further comprising a package encapsulating the light-emitting diode and the light reflective layer.
17 . The light-emitting structure of claim 1 , wherein the light-emitting device comprises a light-emitting diode, and the light-emitting structure further comprises a package encapsulating the light-emitting diode, and the light reflective layer is disposed on a top surface of the package.
18 . The light-emitting structure of claim 16 , wherein the package comprises a wavelength converting material.
19 . A light-emitting module, comprising:
a plurality of the light-emitting structures of claim 1 arranged in an array on the substrate.
20 . The light-emitting module of claim 19 , wherein the array is a hexagonal array.