Light-emitting device
View Patent ↗A light-emitting device of an embodiment of the present application comprises a substrate; a first semiconductor light-emitting structure formed on the substrate, wherein the first semiconductor light-emitting structure comprises a first semiconductor layer having a first conductivity type, a second semiconductor layer having a second conductivity type and a first active layer formed between the first semiconductor layer and the second semiconductor layer, wherein the first active layer is capable of emitting a first light having a first dominant wavelength; and a first thermal-sensitive layer formed on a path of the first light, wherein the first thermal-sensitive layer comprises a material characteristic which varies with a temperature change.
1. A light-emitting device, comprising:
a substrate;
a first semiconductor light-emitting structure formed on the substrate, wherein the first semiconductor light-emitting structure comprises:
a first semiconductor layer having a first conductivity type;
a second semiconductor layer having a second conductivity type; and
a first active layer formed between the first semiconductor layer and the second semiconductor layer, wherein the first active layer is capable of emitting a first light having a first dominant wavelength; and
a first thermal-sensitive layer formed on a path of the first light, wherein the first thermal-sensitive layer comprises a material characteristic which varies within a temperature range and a first intensity difference of the first light after being transmitted through the first thermal-sensitive layer within the temperature range is smaller than a second intensity difference of the first light before being transmitted into the first thermal-sensitive layer within the temperature range.
2. The light-emitting device of claim 1 , wherein the first thermal-sensitive layer contacts with one surface of the first semiconductor light-emitting structure.
3. The light-emitting device of claim 1 , further comprising a light-pervious layer covering the first semiconductor light-emitting structure.
4. The light-emitting device of claim 3 , wherein the first thermal-sensitive layer is formed between the light-pervious layer and the first semiconductor light-emitting structure.
5. The light-emitting device of claim 1 , further comprising a wavelength converting material formed on the path of the first light.
6. The light-emitting device of claim 5 , wherein the wavelength converting material is formed in the light-pervious layer.
7. The light-emitting device of claim 5 , further comprising a second semiconductor light-emitting structure formed on the substrate, adjacent to the first semiconductor light-emitting structure and covered by the light-pervious layer, wherein the second semiconductor light-emitting structure comprises:
a third semiconductor layer having the first conductivity type;
a fourth semiconductor layer having the second conductivity type; and
a second active layer formed between the third semiconductor layer and the fourth semiconductor layer, wherein the second active layer is capable of emitting a second light having a second dominant wavelength.
8. The light-emitting device of claim 7 , wherein the wavelength converting material is formed on a surface of the first semiconductor light-emitting structure.
9. The light-emitting device of claim 7 , further comprising a second thermal-sensitive layer formed on a surface of the second semiconductor light-emitting structure.
10. The light-emitting device of claim 9 , wherein a material and/or a thickness of the second thermal-sensitive layer is different from that of the first thermal-sensitive layer.
11. The light-emitting device of claim 3 , wherein the first thermal-sensitive layer is formed on the light-pervious layer.
12. The light-emitting device of claim 3 , further comprising a wavelength converting material formed on the light-pervious layer.
13. The light-emitting device of claim 1 , wherein the material characteristic includes at least one of transmittance and refractive index.
14. The light-emitting device of claim 13 , wherein the transmittance with respect to the first light is directly proportional to the temperature in the temperature range.
15. The light-emitting device of claim 1 , wherein the thermal-sensitive layer comprises organic compound, inorganic compound, or liquid crystal.
16. The light-emitting device of claim 13 , wherein the thermal-sensitive layer comprises a first material having a first refractive index and a second material having a second refractive index.
17. The light-emitting device of claim 16 , wherein a difference between the first refractive index and the second refractive index is substantially smaller than 10% when a junction temperature of the active layer is above 60° C.
18. The light-emitting device of claim 17 , wherein the first material comprises liquid crystal and the second material comprises resin.
19. The light-emitting device of claim 1 , wherein the first light comprises red light.
20. The light-emitting device of claim 1 , wherein the temperature range comprises a first temperature and a second temperature higher than the first temperature, and an intensity of the first light attenuates from the first temperature to the second temperature.