Optical coupling layer to improve output flux in LEDs
AssigneeLumileds LLC
InventorsAntonio Lopez-Julia, Jens Meyer, Marcel van Gerwen, Ronja Missong, Joerg Feldmann, Hans-Helmut Bechtel
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Abstract
An optical coupling structures are disposed on light output surfaces of semiconductor LEDs of a miniLED or microLED array to facilitate coupling of light emitted by the semiconductor LEDs through the light output surfaces. The optical coupling structures comprise light scattering particles and/or air voids embedded in or coated with a thin layer of a material that has an index of refraction close to or matching the index of refraction of the material forming the light output surface of the semiconductor LEDs.
Claims22
An apparatus comprising:
- (a) an array of semiconductor light emitting diodes having corresponding light output surfaces, each light emitting diode (i) having transverse dimensions less than about 1.0 millimeters and (ii) being separated from adjacent light emitting diodes of the array by less than about 0.10 millimeters;
- and
- (b) a corresponding optical coupling structure disposed on the corresponding light output surface of each light emitting diode of the array, each optical coupling structure comprising a plurality of light scattering particles coated with or embedded in a layer of transparent material, the layer of transparent material in physical contact with the corresponding light output surface and having an index of refraction matching or approximately matching an index of refraction of the corresponding light output surface.
A method for making a light emitting device, the method comprising:
- forming, on a corresponding light output surface of each semiconductor light emitting diode of an array, a corresponding optical coupling structure comprising light scattering particles coated by or embedded in a layer of transparent material having an index of refraction matching or approximately matching an index of refraction of the corresponding light output surface, each light emitting diode (i) having transverse dimensions less than about 1.0 millimeter and (ii) being separated from adjacent light emitting diodes of the array by less than about 0.10 millimeters.
Dependencies are inferred from the claim text.