Light-emitting device comprising porous alumina, and corresponding method of fabrication
AssigneeC.R.F. Societa Consortile per Azioni
InventorsVito Lambertini, Nello Li Pira, Piermario Repetto
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Abstract
A light-emitting device, in particular a backlight device, comprises a transparent substrate (2) having a front surface and a rear surface, in which associated to the rear surface are means for generating an electromagnetic radiation that is able to pass through the substrate and come out of the front surface. According to the invention, the device comprises a layer of porous alumina which operates so as to inhibit propagation of said electromagnetic radiation in the directions parallel to the plane of the substrate, thus improving the efficiency of extraction of light from the substrate and increasing the directionality of the emitted light.
Claims15
A light-emitting device, comprising
- a transparent substrate having a front surface and a rear surface, one of said surfaces identifying a plane of the substrate,
- means for generating an electromagnetic radiation comprising a first electrode, a second electrode and an electroluminescent material, said means being oriented with respect to said rear surface such that said electromagnetic radiation passes through the substrate to come out of the front surface thereof, and
- a layer of porous alumina,
- wherein the first and the second electrodes are both in electrical contact with the electroluminescent material, and the layer of porous alumina is structured to inhibit propagation of said electromagnetic radiation in directions parallel to the plane of the substrate, so as to improve the efficiency of extraction of light from the substrate and increase directionality of emitted light.
A light-emitting device, in particular a backlight device, comprising
- a transparent substrate having a front surface and a rear surface, one of said surfaces identifying a plane of the substrate,
- means for generating an electromagnetic radiation, and
- a layer of porous alumina, wherein
- said means are associated to said rear surface and oriented with respect to said rear surface such that said electromagnetic radiation passes through the substrate to come out of the front surface thereof, and
- said layer of porous alumina is on said front surface and is structured to inhibit propagation of said electromagnetic radiation in directions parallel to the plane of the substrate, so as to improve efficiency of extraction of light from the substrate and increase directionality of the emitted light.
A light-emitting device having a two-dimensional photonic crystal, a transparent plate with a front surface and a rear surface, as well as means for generating light which are oriented with respect to said rear surface such that said light passes through the plate to come out of the front surface thereof, in order to inhibit propagation of the light in directions parallel to a plane of the transparent plate identified by one of said surfaces, so as to improve efficiency of extraction of light from the plate and increase directionality of the emitted light,
- wherein the two-dimensional photonic crystal comprises anodized porous alumina.
A fluorescent lamp bulb for lighting having a two-dimensional photonic crystal, a transparent plate with a front surface and a rear surface, as well as means for generating light which are oriented with respect to said rear surface such that said light passes through the plate to come out of the front surface thereof, in order to inhibit propagation of the light in directions parallel to a plane of the plate identified by one of said surfaces, so as to improve efficiency of extraction of light from the plate and increase directionality of the emitted light,
- wherein the two-dimensional photonic crystal comprises anodized porous alumina.
Dependencies are inferred from the claim text.