Advanced light extraction structure
Light-emitting devices and methods of making the same are described whereby lenses of any array include a material with a higher refractive index than an encapsulation layer of a substrate layer, the refractive index of the material being in a range of greater than 1.7 to 1.9 at 400 nm. The material forming the lenses includes nanocomposite comprised of inorganic nanocrystals and a polymeric matrix, wherein the nanocrystals are selected from the group consisting of ZrO 2 , ZnO, MgO, HfO 2 , NbO 5 , Ta 2 O 5 and Y 2 O 3 . A 3-4 micron thick sample of the nanocomposite has an optical transmittance of at least 80% over a range of 440 nm to 800 nm.
1. A light emitting device comprising, in order:
an encapsulation layer or a substrate layer,
an array of lenses,
an array of light emitting pixels at least partially covered by the array of lenses, wherein
at least one of the lenses covers at least one of the pixels, and
the lenses comprise a material with higher refractive index than the encapsulation layer or substrate layer, wherein
the refractive index of the lenses have a refractive index gradient profile in the range of 1.6 to 1.7 at a wavelength of 400 nm along at least one dimension of the lens, wherein
the material comprises a nanocomposite comprising inorganic nanocrystals and a polymeric matrix, and wherein the inorganic nanocrystals comprise ZrO 2 , ZnO, MgO, HfO 2 , Nb 2 O 5 , Ta 2 O 5 , or Y 2 O 3 .
2. The device of claim 1 , wherein the at least one lens which covers at least one of the pixels comprises a light emitting diode (LED) or an organic light emitting diode (OLED).
3. The device of claim 1 , wherein the device further comprises a planarization layer between the array of lenses and the encapsulation or substrate layer.
4. The device of claim 1 , wherein the device further comprises a transparent conductor layer between the array of lenses and the array of light emitting pixels.
5. The device of claim 1 , wherein at least one lens of the array of lenses at least partially covers more than one pixel of the array of light emitting pixels.
6. The device of claim 5 , wherein the at least one lens comprises at least one lens element selected from the group consisting of a singlet lens, an achromatic lens doublet, a prism, a filter, a polarizer, a reflector, and a Fresnel lens.
7. The device of claim 1 , wherein the shape of the lenses of the array of lenses are at least one of spherical, semi-spherical, hyper-semispherical, parabolic, concave, convex, or sub-wavelength pyramid array, and/or comprise a surface texture, or other surface curvature, or a Fresnel lens.
8. The device of claim 1 , wherein the graded or gradient lens comprises a curved surface.
9. The device of claim 1 , wherein each of the lenses is separated from an active region of the light emitting device by less than the wavelength of the highest energy photons emitted by the light emitting device.
10. The device of claim 1 , wherein the nanocomposite is UV curable.
11. The device of claim 1 , wherein the nanocomposite is thermally curable.
12. The device of claim 1 , wherein the inorganic nanocrystals comprise ZrO 2 .
13. The device of claim 1 , wherein the inorganic nanocrystals are smaller than 10 nm in at least one dimension.
14. The device of claim 1 , wherein the polymer matrix comprises a material selected from the group consisting of acrylic, epoxy, silicone, siloxane, polycarbonate, polyurethane, polyimides, poly(3,4-ethylenedioxythiophene) (PEDOT), poly(styrene sulfonate) (PSS), doped PEDOT, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), doped poly(4,4-dioctylcyclopentadithiophene), and their corresponding monomers and/or oligomers.
15. An array of nanocomposite lenses comprising:
a material with a higher refractive index than an encapsulation layer or substrate layer of a light emitting device comprising an encapsulation layer or a substrate layer and the array of lenses, wherein
the refractive index of the lenses have a refractive index gradient profile in the range of 1.6 to 1.7 at a wavelength of 400 nm along at least one dimension of the lens and comprises a nanocomposite material comprising inorganic nanocrystals and a polymeric matrix, and wherein the inorganic nanocrystals comprise ZrO 2 , ZnO, MgO, HfO 2 , Nb 2 O 5 , Ta 2 O 5 , or Y 2 O 3 .
16. The array of claim 15 , wherein the shape of the lenses of the array of lenses are at least one of spherical, semi-spherical, hyper-semispherical, parabolic, concave, convex, or sub-wavelength pyramid array, and/or comprise a surface texture, or other surface curvature, or a Fresnel lens.
17. The array of claim 15 , wherein the graded or gradient lens comprises a curved surface.
18. The array of claim 15 , wherein the lenses of the array of lenses comprise lens elements selected from the group consisting of a singlet lens, an achromatic lens doublet, a prism, a filter, a polarizer, a reflector and a Fresnel lens.
19. The array of claim 15 , wherein the nanocomposite is UV cured.
20. The array of claim 15 , wherein the nanocomposite is thermally cured.
21. The array of claim 15 , wherein the inorganic nanocrystals comprise ZrO 2 .
22. The array of claim 15 , wherein the inorganic nanocrystals are smaller than 10 nm in at least one dimension.
23. The array of claim 15 , wherein the polymer matrix comprises a material selected from the group consisting of acrylic, epoxy, silicone, siloxane, polycarbonate, polyurethane, polyimides, poly(3,4-ethylenedioxythiophene) (PEDOT), poly(styrene sulfonate) (PSS), doped PEDOT, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), doped poly(4,4-dioctylcyclopentadithiophene), and their corresponding monomers and/or oligomers.
24. A telephone, tablet computer, laptop computer, television, watch or display device comprising an array of claim 15 .
25. An organic light emitting diode (OLED) display comprising:
an array of light emitting pixels, and an array of lenses, wherein
the refractive index of the lenses have a refractive index gradient profile in the range of 1.6 to greater than 1.7 at a wavelength of 400 nm along at least one dimension of the lens and comprises a nanocomposite, wherein
the nanocomposite comprises inorganic nanocrystals and wherein at least one of the lenses is arranged so as to enhance overall light extraction efficiency from at least one pixel of the array of light emitting pixels, and wherein
the array of lenses are not in contact with a planarization layer and not in contact with a substrate layer.
26. The OLED display of claim 25 , wherein the nanocomposite is UV cured.
27. The OLED display of claim 25 , wherein the nanocomposite is thermally curable cured.
28. The OLED display of claim 25 , wherein the nanocomposite comprises nanocrystals of ZrO 2 , ZnO, MgO, HfO 2 , Nb 2 O 5 , Ta 2 O 5 , or Y 2 O 3 .
29. The OLED display of claim 25 , wherein the nanocrystals have a size of less than 10 nm in at least one dimension.
30. The OLED display of claim 25 , wherein the nanocomposite comprises a polymer, wherein the polymer optionally comprises an acrylic, an epoxy or a silicone.
31. The OLED display of claim 25 , wherein the polymer comprises a siloxane, a polycarbonate, a polyurethane, a polyimide, poly(3,4-ethylenedioxythiophene) (PEDOT), poly(styrene sulfonate) (PSS), polyethylene terephthalate (PET), Polyethylene polyethylene naphthalate (PEN), or poly(4,4-dioctylcyclopentadithiophene).
32. The OLED display of claim 25 , wherein at least one of the lenses covers a single pixel of the array of light emitting pixels.
33. The OLED display of claim 25 , wherein at least one of the lenses covers multiple pixels of the array of light emitting pixels.
34. The OLED display of claim 25 , wherein a lens of the array of lenses comprises a spherical surface, a semi-spherical surface, a hyper-hemispherical surface or a parabolic surface.
35. The OLED display of claim 25 , wherein a lens of the array of lenses comprises a concave surface, a convex surface, a sub-wavelength pyramid array surface or a textured surface.
36. The OLED display of claim 35 , wherein the array of lenses is separated from the array of light emitting pixels by a distance of less than a wavelength of the highest energy photons emitted by the array of pixels.