Advanced light extraction structure
This presently disclosed technology relates to Organic Light Emitting Diodes (OLEDs), more particularly it relates to OLED display extraction and nanocomposite formulations that can be used for the light extraction structure. The OLEDs comprise, in order, an encapsulation layer or a substrate layer, an array of lenses, and an array of light emitting pixels at least partially covered by said array of lenses, wherein at least one of the lenses covers at least one of the pixel, and said lenses comprises a material with higher refractive index than the encapsulation layer or substrate layer.
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, the refractive index of the material being in the range of greater than 1.7 to 1.9 at a wavelength of 400 nm, 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, a lens with graded or gradient index profile, 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 lenses of the array of lenses comprise a graded or gradient index profile along at least one dimension of the lens.
9. The device of claim 8 , wherein the graded or gradient lens comprises a curved surface.
10. 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.
11. The device of claim 1 , wherein the nanocomposite was UV curable.
12. The device of claim 1 , wherein the nanocomposite was thermally curable.
13. The device of claim 1 , wherein the inorganic nanocrystals comprise ZrO 2 .
14. The device of claim 1 , wherein the inorganic nanocrystals are smaller than 10 nm in at least one dimension.
15. 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.
16. An OLED display comprising a device of claim 1 .
17. A process of making a display comprising incorporating a device of claim 1 in to a display device.
18. A telephone, tablet computer, laptop computer, television, watch or display device comprising a display of claim 16 .
19. An array of nanocomposite lenses comprising a material with 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 material 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 .
20. The array of claim 19 , 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.
21. The array of claim 19 , wherein lenses of the array of lenses comprise a graded or gradient index profile along at least one dimension of the lens.
22. The array of claim 21 , wherein the graded or gradient lens comprises a curved surface.
23. The array of claim 19 , wherein the lenses of the array of lenses comprise lens elements selected from the group consisting of a singlet lens, a lens with graded or gradient index profile, an achromatic lens doublet, a prism, a filter, a polarizer, a reflector and a Fresnel lens.
24. The array of claim 19 , wherein the nanocomposite is UV cured.
25. The array of claim 19 , wherein the nanocomposite is thermally cured.
26. The array of claim 19 , wherein the inorganic nanocrystals comprise ZrO 2 .
27. The array of claim 19 , wherein the inorganic nanocrystals are smaller than 10 nm in at least one dimension.
28. The array of claim 19 , 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.
29. A telephone, tablet computer, laptop computer, television, watch or display device comprising a device of claim 1 .
30. A telephone, tablet computer, laptop computer, television, watch or display device comprising an array of claim 19 .
31. An organic light emitting diode (OLED) display comprising:
an array of light emitting pixels, and
an array of lenses, wherein
the array of lenses comprises a nanocomposite, wherein the nanocomposite comprises inorganic nanocrystals and has a refractive index between 1.6 and 1.9 at a wavelength of 400 nm; 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.
32. The OLED display of claim 31 , wherein the nanocomposite is UV cured.
33. The OLED display of claim 31 , wherein the nanocomposite is thermally curable cured.
34. The OLED display of claim 31 , wherein the nanocomposite comprises ZrO 2 , ZnO, MgO, HfO 2 , Nb 2 O 5 , Ta 2 O 5 , or Y 2 O 3 nanocrystals.
35. The OLED display of claim 34 , wherein the nanocrystals have a size of less than 10 nm in at least one dimension.
36. The OLED display of claim 31 , wherein the nanocomposite comprises a polymer, wherein the polymer optionally comprises an acrylic, an epoxy or a silicone.
37. The OLED display of claim 36 , 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).
38. The OLED display of claim 31 , wherein at least one of the lenses covers a single pixel of the array of light emitting pixels.
39. The OLED display of claim 31 , wherein at least one of the lenses covers multiple pixels of the array of light emitting pixels.
40. The OLED display of claim 31 , wherein a lens of the array of lenses comprises a spherical surface, a semi-spherical surface, a hyper-hemispherical surface or a parabolic surface.
41. The OLED display of claim 31 , 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.
42. The OLED display of claim 31 , wherein a lens of the array of lenses comprises a graded or gradient index profile along at least one dimension of the lens.
43. The OLED display of claim 31 , 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.