Color uniformity in converted light emitting diode using nano-structures
A nano-structure layer is disclosed. The nano-structure layer includes an array of nano-structure material configured to receive a first light beam at a first angle of incidence and to emit the first light beam at a second angle greater than the first angle, the nano-structure material each having a largest dimension of less than 1000 nm.
1. A light emitting device comprising:
a semiconductor diode structure that in operation emits a first light comprising first light rays and second light rays;
a substrate transparent to the first light and comprising a top surface, a bottom surface oppositely positioned from the top surface, and side surfaces connecting the top surface and the bottom surface, the bottom surface disposed on or adjacent the semiconductor diode structure;
a wavelength converting structure comprising a top surface and an oppositely positioned bottom surface disposed on or adjacent the top surface of the substrate; and
a 1D photonic crystal comprising nanoantennas, the 1D photonic crystal positioned between the top surface of the substrate and the top surface of the wavelength converting structure and in operation reflects the first light rays and transmits the second light rays into the wavelength converting structure at a third angle with respect to the 1D photonic crystal greater than a second angle with respect to the 1D photonic crystal, the semiconductor diode structure in operation emits the first light rays to be incident on the 1D photonic crystal from a substrate side at a first angle with respect to the 1D photonic crystal less than or equal to a cutoff angle and configured to emit the second light rays to be incident on the 1D photonic crystal from the substrate side at the second angle, the second angle being greater than the cutoff angle.
2. The light emitting device of claim 1 , wherein the 1D photonic crystal is disposed on or adjacent to the bottom surface of the wavelength converting structure.
3. The light emitting device of claim 1 , wherein the 1D photonic crystal is disposed within the wavelength converting structure.
4. The light emitting device of claim 1 , wherein the nanoantennas together comprise a periodic lattice.
5. The light emitting device of claim 1 , wherein the nanoantennas each have a largest dimension less than a wavelength of the first light.
6. The light emitting device of claim 1 , wherein at least one of the nanoantennas is an asymmetric object.
7. The light emitting device of claim 1 , wherein at least one nanoantenna comprises two or more light scattering objects.
8. The light emitting device of claim 7 , wherein the two or more light scattering objects are symmetric objects.
9. The light emitting device of claim 8 , wherein the two or more light scattering objects are in an asymmetrical arrangement.
10. The light emitting device of claim 1 , further comprising an adhesive layer between the substrate and the wavelength converting structure and having a top surface, a bottom surface, and side surfaces connecting the top surface and the bottom surface, the top surface of the adhesive layer being a different surface from a top surface of the 1D photonic crystal.
11. A light emitting device comprising:
a semiconductor diode structure that in operation emits a first light comprising light rays;
a substrate transparent to the first light and comprising a top surface, a bottom surface oppositely positioned from the top surface, and side surfaces connecting the top surface and the bottom surface, the bottom surface disposed on or adjacent the semiconductor diode structure;
a wavelength converting structure comprising a top surface and an oppositely positioned bottom surface disposed on or adjacent the top surface of the substrate; and
a 2D photonic crystal comprising nanoantennas, the 2D photonic crystal positioned between the top surface of the substrate and the top surface of the wavelength converting structure and that in operation transmits the light rays into the wavelength converting structure at an angle with respect to the 2D photonic crystal greater than an angle of incidence of the light rays on the 2D photonic crystal, the semiconductor diode structure in operation emits the light rays of first light to be incident on the 2D photonic crystal from a substrate side of the 2D photonic crystal.
12. The light emitting device of claim 11 , wherein the 2D photonic crystal is disposed on or adjacent the bottom surface of the wavelength converting structure.
13. The light emitting device of claim 11 , wherein the 2D photonic crystal is disposed within the wavelength converting structure.
14. The light emitting device of claim 11 , wherein the nanoantennas together comprise a periodic lattice.
15. The light emitting device of claim 11 , wherein the nanoantennas each have a largest dimension less than a wavelength of the first light.
16. The light emitting device of claim 11 , wherein at least one nanoantenna is an asymmetric object.
17. The light emitting device of claim 11 , wherein at least one nanoantenna comprises two or more light scattering objects.
18. The light emitting device of claim 11 , wherein the two or more light scattering objects are symmetric objects.
19. The light emitting device of claim 18 , wherein the two or more light scattering objects are in an asymmetrical arrangement.
20. The light emitting device of claim 11 , further comprising an adhesive layer between the substrate and the wavelength converting structure and having a top surface, a bottom surface, and side surfaces connecting the top surface and the bottom surface, the top surface of the adhesive layer being a different surface from a top surface of the 2D photonic crystal.