Light-emitting device
A light-emitting device includes a light-emitting element, and a covering layer. The light-emitting element includes a top surface, a bottom surface, a light-emitting stack between the top surface and the bottom surface, and an adhesion enhancing layer surrounding the light-emitting stack. The covering layer covers the light-emitting element and contacts the adhesion enhancing layer. Moreover, the adhesion enhancing layer includes an oxide and a thickness greater than 5 nm and less than 1000 nm.
1. A light-emitting device, comprising:
a light-emitting element, having a topmost surface and a bottom surface, and comprising:
a light-emitting stack comprising a plurality of outermost side surfaces;
a first electrical contact and a second electrical contact, arranged under the light-emitting stack; and
an adhesion enhancing layer surrounding the plurality of outermost side surfaces and comprising an oxide; and
a covering layer, covering the light-emitting element and contacting the adhesion enhancing layer,
wherein the adhesion enhancing layer has a thickness greater than 5 nm and less than 1000 nm, and
wherein the adhesion enhancing layer does not cover the bottom surface directly between the first electrical contact and the second electrical contact.
2. The light-emitting device according to claim 1 , wherein a total contact area is defined as a total area that the covering layer contacts the light-emitting element, an enhanced contact area is defined as a total area that the covering layer contacts the adhesion enhancing layer, a ratio of the enhanced contact area to the total contact area is in the range of 0.25 and 0.6.
3. The light-emitting device of claim 1 , wherein the adhesion enhancing layer has a refractive index greater than 1.90 at a peak wavelength of about 400 nm to 490 nm.
4. The light-emitting device of claim 1 , wherein the light-emitting device is connected to the covering layer by an adhesion strength not less than 96774 g/cm 2 .
5. The light-emitting device of claim 1 , wherein the light-emitting element further comprises a growth substrate which is epitaxially connected to the light-emitting stack, and has a material composition different from the light-emitting stack.
6. The light-emitting device of claim 5 , wherein the adhesion enhancing layer directly contacts the growth substrate and exposes the topmost surface.
7. The light-emitting device of claim 5 , wherein the adhesion enhancing layer comprises a sidewall which has a hydroxyl group density greater than the topmost surface.
8. The light-emitting device of claim 1 , wherein the adhesion enhancing layer has an upper surface lower than the topmost surface.
9. The light-emitting device of claim 1 , wherein the adhesion enhancing layer comprises an inclined plane.
10. The light-emitting device of claim 1 , further comprising a transparent substrate formed on the covering layer.
11. The light-emitting device of claim 1 , further comprising a reflective layer surrounding the covering layer.
12. The light-emitting device of claim 11 , wherein the reflective layer comprises a distributed Bragg reflector.
13. The light-emitting device of claim 1 , wherein the covering layer comprises a wavelength conversion layer.
14. The light-emitting device of claim 13 , wherein the wavelength conversion layer comprises a wavelength conversion material and a transparent binder.
15. The light-emitting device of claim 1 , wherein the covering layer has an inclined plane.
16. The light-emitting device of claim 5 , wherein the adhesion enhancing layer has a refractive index greater than that of the growth substrate.
17. The light-emitting device of claim 5 , wherein the adhesion enhancing layer comprises an inner surface directly contacting the growth substrate.
18. The light-emitting device of claim 1 , wherein the adhesion enhancing layer is formed in a single material layer configuration.