EP2033237A1 - Dispositif à del avec construction semi-conductrice réémettrice et réflecteur - Google Patents

Dispositif à del avec construction semi-conductrice réémettrice et réflecteur

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Publication number
EP2033237A1
EP2033237A1 EP07798368A EP07798368A EP2033237A1 EP 2033237 A1 EP2033237 A1 EP 2033237A1 EP 07798368 A EP07798368 A EP 07798368A EP 07798368 A EP07798368 A EP 07798368A EP 2033237 A1 EP2033237 A1 EP 2033237A1
Authority
EP
European Patent Office
Prior art keywords
reflector
emitting semiconductor
light
semiconductor construction
led
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP07798368A
Other languages
German (de)
English (en)
Other versions
EP2033237A4 (fr
Inventor
Michael A. Haase
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
3M Innovative Properties Co
Original Assignee
3M Innovative Properties Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 3M Innovative Properties Co filed Critical 3M Innovative Properties Co
Publication of EP2033237A1 publication Critical patent/EP2033237A1/fr
Publication of EP2033237A4 publication Critical patent/EP2033237A4/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10H—INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS
    • H10H20/00—Individual inorganic light-emitting semiconductor devices having potential barriers, e.g. light-emitting diodes [LED]
    • H10H20/80—Constructional details
    • H10H20/81—Bodies
    • H10H20/813—Bodies having a plurality of light-emitting regions, e.g. multi-junction LEDs or light-emitting devices having photoluminescent regions within the bodies
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10H—INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS
    • H10H20/00—Individual inorganic light-emitting semiconductor devices having potential barriers, e.g. light-emitting diodes [LED]
    • H10H20/80—Constructional details
    • H10H20/84—Coatings, e.g. passivation layers or antireflective coatings
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10H—INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS
    • H10H20/00—Individual inorganic light-emitting semiconductor devices having potential barriers, e.g. light-emitting diodes [LED]
    • H10H20/80—Constructional details
    • H10H20/85—Packages
    • H10H20/851—Wavelength conversion means
    • H10H20/8511—Wavelength conversion means characterised by their material, e.g. binder
    • H10H20/8512—Wavelength conversion materials
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10W—GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
    • H10W90/00—Package configurations
    • H10W90/701—Package configurations characterised by the relative positions of pads or connectors relative to package parts
    • H10W90/751—Package configurations characterised by the relative positions of pads or connectors relative to package parts of bond wires
    • H10W90/756—Package configurations characterised by the relative positions of pads or connectors relative to package parts of bond wires between a chip and a stacked lead frame, conducting package substrate or heat sink

Definitions

  • LEDs Light emitting diodes
  • Conventional LED's contain a single pn junction.
  • the pn junction may include an intermediate undoped region; this type of pn junction may also be called a pin junction.
  • conventional LED's pass an electrical current much more readily in one direction, i.e., in the direction where electrons are moving from the n-region to the p-region. When a current passes in the "forward" direction through the LED, electrons from the n-region recombine with holes from the p-region, generating photons of light.
  • the light emitted by a conventional LED is monochromatic in appearance; that is, it is generated in a single narrow band of wavelengths.
  • the wavelength of the emitted light corresponds to the energy associated with electron-hole pair recombination. In the simplest case, that energy is approximately the band gap energy of the semiconductor in which the recombination occurs.
  • the present disclosure provides a device comprising: a) an LED capable of emitting light at a first wavelength; b) a re-emitting semiconductor construction which comprises a potential well not located within a pn junction; and c) a reflector positioned to reflect light emitted from the LED onto the re-emitting semiconductor construction.
  • the re-emitting semiconductor construction may additionally comprise an absorbing layer closely adjacent or immediately adjacent to a potential well. Potential wells may be quantum wells.
  • the re-emitting semiconductor construction is capable of emitting light at a second wavelength and the reflector reflects light at said first wavelength and transmits light at said second wavelength.
  • the reflector may be a multilayer reflector, a non-planar flexible multilayer reflector, or a reflective polarizer layer.
  • the present invention provides a graphic display device comprising the LED device according to the present invention. In another aspect, the present invention provides an illumination device comprising the LED device according to the present invention.
  • immediately adjacent means next in sequence without intervening layers
  • closely adjacent means next in sequence with one or a few intervening layers
  • surrounding means both before and after in sequence
  • Transition energy means electron-hole recombination energy
  • lattice-matched means, with reference to two crystalline materials, such as an epitaxial film on a substrate, that each material taken in isolation has a lattice constant, and that these lattice constants are substantially equal, typically not more than 0.2% different from each other, more typically not more than 0.1% different from each other, and most typically not more than 0.01% different from each other;
  • “pseudomorphic” means, with reference to a first crystalline layer of given thickness and a second crystalline layer, such as an epitaxial film and a substrate, that each layer taken in isolation has a lattice constant, and that these lattice constants are sufficiently similar so that the first layer, in the given thickness, can adopt the lattice spacing of the second layer in the plane of the layer substantially without misfit defects.
  • Fig. 1 is a flat-band diagram of conduction and valence bands of semiconductors in a construction according to one embodiment of the present invention. Layer thickness is not represented to scale.
  • Fig. 2 is a graph indicating lattice constant and band gap energy for a variety of II- VI binary compounds and alloys thereof.
  • Fig. 3 is a graph representing the spectrum of light that emits from a device according to one embodiment of the present invention.
  • Fig. 4 is a flat-band diagram of conduction and valence bands of semiconductors in a construction according to one embodiment of the present invention. Layer thickness is not represented to scale.
  • Fig. 5 is a schematic sectional view of a device according to the present disclosure.
  • Fig. 6 is a sectional view of a re-emitting semiconductor construction and reflector assembly used in the device of Fig. 4;
  • FIGs. 7-9 are schematic sectional views of alternative a devices according to the present disclosure
  • Fig. 10 depicts a portion of still another device according to the present disclosure
  • Fig. 11 is a schematic sectional view of still another device according to the present disclosure.
  • Fig. 12 is a schematic side view of another device that utilizes front surface illumination, as does the embodiment of Fig. 10;
  • Fig. 13 is a schematic side view of a device that makes use of an arrangement of nonimaging concentrators;
  • Fig. 14 is a close-up view of a portion of Fig. 12; and Figs. 15-19 are schematic sectional views of other embodiments of the present disclosure.
  • the present invention provides a device comprising: an LED; a re-emitting semiconductor construction and a reflector positioned to reflect light emitted from the LED onto the re-emitting semiconductor construction.
  • the LED is capable of emitting light at a first wavelength and the a re-emitting semiconductor construction is capable of absorbing light at that first wavelength and re-emitting light at a second wavelength.
  • the a re-emitting semiconductor construction comprises a potential well not located within a pn junction.
  • the potential wells of the re-emitting semiconductor construction are typically but not necessarily quantum wells.
  • the device comprises a reflector which transmits light at the first wavelength and reflects at least a portion of light at the second wavelength.
  • This reflector may be positioned between the LED and the re-emitting semiconductor construction.
  • the LED emits photons in response to an electric current and the re-emitting semiconductor construction emits photons in response to the absorption of a portion of the photons emitted from the LED.
  • the re-emitting semiconductor construction additionally comprises an absorbing layer closely or immediately adjacent to the potential well. Absorbing layers typically have a band gap energy which is less than or equal to the energy of photons emitted by the LED and greater than the transition energy of the potential wells of the re-emitting semiconductor construction. In typical operation the absorbing layers assist absorption of photons emitted from the LED.
  • the re-emitting semiconductor construction additionally comprises at least one second potential well not located within a pn junction having a second transition energy not equal to the transition energy of the first potential well.
  • the LED is a UV LED.
  • the re-emitting semiconductor construction comprises at least one first potential well not located within a pn junction having a first transition energy corresponding to blue- wavelength light, at least one second potential well not located within a pn junction having a second transition energy corresponding to green- wavelength light, and at least one third potential well not located within a pn junction having a third transition energy corresponding to red-wavelength light.
  • the LED is a visible light LED, typically a green, blue or violet LED, more typically a green or blue LED, and most typically a blue LED.
  • the re-emitting semiconductor construction comprises at least one first potential well not located within a pn junction having a first transition energy corresponding to yellow- or green-wavelength light, more typically green-wavelength light, and at least one second potential well not located within a pn junction having a second transition energy corresponding to orange- or red- wavelength light, more typically red- wavelength light.
  • the re-emitting semiconductor construction may comprise additional potential wells and additional absorbing layers.
  • any suitable LED may be used in the practice of the present invention.
  • Elements of the device according to the present invention may be composed of any suitable semiconductors, including Group IV elements such as Si or Ge (other than in light-emitting layers), III-V compounds such as InAs, AlAs, GaAs, InP, AlP, GaP, InSb, AlSb, GaSb, and alloys thereof, II-VI compounds such as ZnSe, CdSe, BeSe, MgSe, ZnTe, CdTe, BeTe, MgTe, ZnS, CdS, BeS, MgS and alloys thereof, or alloys of any of the above.
  • Group IV elements such as Si or Ge (other than in light-emitting layers)
  • III-V compounds such as InAs, AlAs, GaAs, InP, AlP, GaP, InSb, AlSb, GaSb, and alloys thereof
  • II-VI compounds such as ZnSe, CdSe
  • the semiconductors may be n-doped or p-doped by any suitable method or by inclusion of any suitable dopant.
  • the LED is a III-V semiconductor device and the re-emitting semiconductor construction is a II-VI semiconductor device.
  • the compositions of the various layers of a component of the device are selected in light of the following considerations.
  • Each layer typically will be pseudomorphic to the substrate at the thickness given for that layer or lattice matched to the substrate. Alternately, each layer may be pseudomorphic or lattice matched to immediately adjacent layers.
  • Potential well layer materials and thicknesses are typically chosen so as to provide a desired transition energy, which will correspond to the wavelength of light to be emitted from the quantum well. For example, the points labeled 460 nm, 540 nm and 630 nm in Fig.
  • each quantum well layer represents Cd(Mg)ZnSe alloys having lattice constants close to that for an InP substrate (5.8687 Angstroms or 0.58687 nm) and band gap energies corresponding to wavelengths of 460nm (blue), 540nm (green) and 630nm (red).
  • the potential well may be regarded as a quantum well.
  • the thickness of each quantum well layer will determine the amount of quantization energy in the quantum well, which is added to the bulk band gap energy to determine the transition energy in the quantum well.
  • the wavelength associated with each quantum well can be tuned by adjustment of the quantum well layer thickness.
  • thicknesses for quantum well layers are between 1 nm and 100 nm, more typically between 2 nm and 35 nm.
  • the quantization energy translates into a reduction in wavelength of 20 to 50 nm relative to that expected on the basis of the band gap energy alone.
  • Strain in the emitting layer may also change the transition energy for potential wells and quantum wells, including the strain resulting from the imperfect match of lattice constants between pseudomorphic layers.
  • any suitable emission wavelengths may be chosen, including those in the infrared, visible, and ultraviolet bands.
  • the emission wavelengths are chosen so that the combined output of light emitted by the device creates the appearance of any color that can be generated by the combination of two, three or more monochromatic light sources, including white or near-white colors, pastel colors, magenta, cyan, and the like.
  • the device according to the present invention emits light at an invisible infrared or ultraviolet wavelength and at a visible wavelength as an indication that the device is in operation.
  • the LED emits photons of the shortest wavelength, so that photons emitted from the LED have sufficient energy to drive the potential wells in the re-emitting semiconductor construction.
  • the LED is a III-V semiconductor device, such as a blue-emitting GaN-based LED, and re-emitting semiconductor construction is a II-VI semiconductor device.
  • Layer 3 represents a single potential well which is a red-emitting quantum well having a thickness of about 10 nm.
  • Layer 7 represents a single potential well which is a green-emitting quantum well having a thickness of about 10 nm.
  • Layers 2, 4, 6 and 8 represent absorbing layers, each having a thickness of about 1000 nm.
  • Layers 1, 5 and 9 represent support layers. Support layers are typically chosen so as to be substantially transparent to light emitted from quantum wells 3 and 7 and from short- wavelength LED 20. Alternately, the device may comprise multiple red- or green-emitting potential wells or quantum wells separated by absorbing layers and/or support layers.
  • Fig. 1 operates according to the following principles: Blue wavelength photons emitted by the LED and reflected upon the re-emitting semiconductor construction may be absorbed and re-emitted from the green-emitting quantum well 7 as green- wavelength photons or from the red-emitting quantum well 3 as red- wavelength photons. The absorption of a short- wavelength photon generates an electron-hole pair which may then recombine in the quantum wells, with the emission of a photon.
  • the polychromatic combination of blue-, green- and red- wavelength light emitted from the device may appear white or near- white in color.
  • the intensity of blue-, green- and red-wavelength light emitted from the device may be balanced in any suitable manner, including manipulation of the number of quantum wells of each type, the use of filters or reflective layers, and manipulation of the thickness and composition of absorbing layers.
  • Fig. 3 represents a spectrum of light that emits from one embodiment of the device according to the present invention.
  • absorbing layers 2, 4, 5 and 8 may be adapted to absorb photons emitted from the LED by selecting a band gap energy for the absorbing layers that is intermediate between the energy of photons emitted from the LED and the transition energies of quantum wells 3 and 7. Electron-hole pairs generated by absorption of photons in the absorbing layers 2, 4, 6 and 8 are typically captured by the quantum wells 3 and 7 before recombining with concomitant emission of a photon.
  • Absorbing layers may optionally have a gradient in composition over all or a portion of their thickness, so as to funnel or direct electrons and/or holes toward potential wells.
  • the LED and the re-emitting semiconductor construction are provided in a single semiconductor unit.
  • This semiconductor unit typically contains a first potential well located within a pn junction and a second potential well not located within a pn junction.
  • the potential wells are typically quantum wells.
  • the unit is capable of emitting light at two wavelengths, one corresponding to the transition energy of the first potential well and a second corresponding to the transition energy of the second potential well.
  • the first potential well emits photons in response to an electric current passing through the pn junction and the second potential well emits photons in response to the absorption of a portion of the photons emitted from the first potential well.
  • the semiconductor unit may additionally comprise one or more absorbing layers surrounding or closely or immediately adjacent to the second potential well.
  • Absorbing layers typically have a band gap energy which is less than or equal to the transition energy of the first potential well and greater than that of the second potential well. In typical operation the absorbing layers assist absorption of photons emitted from the first potential well.
  • the semiconductor unit may comprise additional potential wells, located within the pn junction or located not within the pn junction, and additional absorbing layers.
  • Fig. 4 is a band diagram representing conduction and valence bands of semiconductors in such a semiconductor unit according to one embodiment of the present invention. Layer thickness is not represented to scale. Table II indicates the composition of layers 1-14 in this embodiment and the band gap energy (E 2 ) for that composition.
  • Layers 10, 11, 12, 13 and 14 represent a pn junction, or, more specifically, a pin junction, since intermediate undoped ("intrinsic" doping) layers 11, 12 and 13 are interposed between n-doped layer 10 and p-doped layer 14.
  • Layer 12 represents a single potential well within the pn junction which is a quantum well having a thickness of about 10 nm. Alternately, the device may comprise multiple potential or quantum wells within the pn junction.
  • Layers 4 and 8 represent second and third potential wells not within a pn junction, each being a quantum well having a thickness of about 10 nm. Alternately, the device may comprise additional potential or quantum wells not within the pn junction.
  • the device may comprise a single potential or quantum well not within the pn junction.
  • Layers 3, 5, 7 and 9 represent absorbing layers, each having a thickness of about 1000 nm.
  • Electrical contacts, not shown, provide a path for supply of electrical current to the pn junction. Electrical contacts conduct electricity and typically are composed of conductive metal. The positive electrical contact is electrically connected, either directly or indirectly through intermediate structures, to layer 14. The negative electrical contact is electrically connected, either directly or indirectly through intermediate structures, to one or more of layers 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10.
  • this embodiment of the present invention operates according to the following principles: When an electrical current passes from layer 14 to layer 10, blue-wavelength photons are emitted from quantum well (12) in the pn junction. Photons traveling in the direction of layer 14 may leave the device. Photons traveling in the opposite direction may be absorbed and re- emitted from the second quantum well (8) as green- wavelength photons or from the third quantum well (4) as red- wavelength photons. The absorption of a blue -wavelength photon generates an electron-hole pair which may then recombine in the second or third quantum wells, with the emission of a photon. Green- or red- wavelength photons traveling in the direction of layer 14 may leave the device.
  • the polychromatic combination of blue-, green- and red- wavelength light emitted from the device may appear white or near- white in color.
  • the intensity of blue-, green- and red- wavelength light emitted from the device may be balanced in any suitable manner, including manipulation of the number of potential wells of each type and the use of filters or reflective layers.
  • Fig. 3 represents a spectrum of light that emits from one embodiment of the device according to the present invention.
  • absorbing layers 3, 5, 7 and 9 may be especially suitable to absorb photons emitted from the first quantum well (12), since they have a band gap energy that is intermediate between the transition energy of the first quantum well (12) and those of the second and third quantum wells (8 and 4). Electron-hole pairs generated by absorption of photons in the absorbing layers 3, 5, 7 and 9 are typically captured by the second or third quantum wells 8 and 4 before recombining with concomitant emission of a photon.
  • Absorbing layers may optionally be doped, typically like to surrounding layers, which in this embodiment would be n-doping. Absorbing layers may optionally have a gradient in composition over all or a portion of their thickness, so as to funnel or direct electrons and/or holes toward potential wells.
  • the layers of the re-emitting semiconductor construction may be partially transparent to the light emitted from the LED.
  • the layers of re-emitting semiconductor construction may block a greater portion or substantially or completely all of the light emitted from the LED, so that a greater portion or substantially or completely all of the light emitted from the device is light re-emitted from the re-emitting semiconductor construction.
  • re-emitting semiconductor construction 10 may include red-, green- and blue- emitting quantum wells.
  • the device according to the present invention may comprise additional layers of conducting, semiconducting or non-conducting materials.
  • Electrical contact layers may be added to provide a path for supply of electrical current to the LED.
  • Light filtering layers may be added to alter or correct the balance of light wavelengths in the light emitted by the adapted LED.
  • the device according to the present invention generates white or near- white light by emitting light at four principal wavelengths in the blue, green, yellow and red bands. In one embodiment, the device according to the present invention generates white or near- white light by emitting light at two principal wavelengths in the blue and yellow bands.
  • the device according to the present invention may comprise additional semiconductor elements comprising active or passive components such as resistors, diodes, zener diodes, capacitors, transistors, bipolar transistors, FET transistors, MOSFET transistors, insulated gate bipolar transistors, phototransistors, photodetectors, SCR' s, thyristors, triacs, voltage regulators, and other circuit elements.
  • the device according to the present invention may comprise an integrated circuit.
  • the device according to the present invention may comprise a display panel or an illumination panel.
  • the LED and the re-emitting semiconductor construction which make up the device according to the present invention may be manufactured by any suitable method, which may include molecular beam epitaxy (MBE), chemical vapor deposition, liquid phase epitaxy and vapor phase epitaxy.
  • the elements of the device according to the present invention may include a substrate. Any suitable substrate may be used in the practice of the present invention. Typical substrate materials include Si, Ge, GaAs, InP, sapphire, SiC and ZnSe. The substrate may be n-doped, p-doped, or semi-insulating, which may be achieved by any suitable method or by inclusion of any suitable dopant. Alternately, the elements of the device according to the present invention may be without a substrate.
  • a multilayer reflector is used, which may be a non-planar flexible multilayer reflector.
  • Multilayer reflectors include polymeric multilayer optical films, i.e., films having tens, hundreds, or thousands of alternating layers of at least a first and second polymer material, whose thicknesses and refractive indices are selected to achieve a desired reflectivity in a desired portion of the spectrum, such as a reflection band limited to UV wavelengths or a reflection band limited to visible wavelengths. See, for example, U.S. Patent 5,882,774 (Jonza et al.).
  • the polymeric multilayer optical films can be processed so that adjacent layer pairs have matching or near-matching, or deliberately mismatched refractive indices associated with a z-axis normal to the film such that the reflectivity of each interface between adjacent layers, for p-polarized light, decreases slowly with angle of incidence, is substantially independent of angle of incidence, or increases with angle of incidence away from the normal.
  • polymeric multilayer optical films also makes available a variety of new embodiments and methods of construction due to the flexibility and formability of such films, whether or not they also have the refractive index relationships referred to above.
  • polymeric multilayer optical film can be permanently deformed by embossing, thermo forming, or other known means to have a 3 -dimensional shape such as a portion of a paraboloid, a sphere, or an ellipsoid. See generally published application US 2002/0154406 (Merrill et al). See also U.S. Patent 5,540,978 (Schrenk) for additional polymeric multilayer film embodiments.
  • polymeric multilayer optical films can be made in high volume roll form, and can also be laminated to other films and coated, and can be die cut or otherwise subdivided into small pieces for easy incorporation into an optical system as further explained below. Suitable methods of subdividing polymeric multilayer optical film are disclosed in pending U.S. Application Serial No. 10/268,118, filed October 10, 2002.
  • the multilayer optical film preferably comprises alternating polymer layers composed of materials that resist degradation when exposed to UV light.
  • a particularly preferred polymer pair is polyethylene terephthalate (PET)/co-polymethylmethacrylate (co-PMMA).
  • PET polyethylene terephthalate
  • co-PMMA co-polymethylmethacrylate
  • the UV stability of polymeric reflectors can also be increased by the incorporation of non-UV absorbing light stabilizers such as hindered amine light stabilizers (HALS).
  • HALS hindered amine light stabilizers
  • the polymeric multilayer optical film can also include transparent metal or metal oxide layers. See e.g. PCT Publication WO 97/01778
  • Figs. 7-9 depict alternative constructions of device 40, 50, 60 utilizing a concave- shaped multilayer optical film LP reflector 46, 56.
  • Spacing LP reflector 46, 56 away from the re-emitting semiconductor construction 42, 52 and curving it to present a concave surface to the re-emitting semiconductor construction 42, 52 and LED 12 helps reduce the range of incidence angles of excitation light impinging on the LP reflector 46, 56, thereby reducing the leakage of LED light through the LP reflector 46, 56 caused by its blue-shift effect.
  • the multilayer optical film is permanently deformed by embossing or other suitable process into a concave surface of suitable shape before immersion in transparent medium 18.
  • the multilayer optical films, whether LP or SP, are specular reflectors within their respective reflection bands. Diffuse reflection from a multilayer optical film is typically negligible.
  • device 40 includes a relatively small area re-emitting semiconductor construction layer 42 disposed on an optional SP reflector 44 composed of a polymeric multilayer optical film.
  • LP reflector 46 has been embossed to acquire a concave shape and positioned next to the other components (42, 44) of the re-emitting semiconductor construction-reflector assembly.
  • LED 12 and heat sink 14 are arranged to direct excitation light emitted by the LED toward the central portion of re-emitting semiconductor construction layer 42.
  • the excitation light has its highest fluence at or near the center of re-emitting semiconductor construction layer 42.
  • Device 60 shown in Fig. 9, is similar to device 50, except the LP reflector 66 now forms an outer surface of the light source. Region 68 can be filled with potting material 18 or other transparent medium.
  • the re-emitting semiconductor construction layers of Figs. 7-9 can be continuous, or patterned to limit the re-emitting semiconductor construction to where it is most effective.
  • the device in the embodiments of Figs. 5 and 7-9 and other embodiments where the re-emitting semiconductor construction-reflector assembly is disposed above and spaced apart from the LED, the device can be manufactured in two halves: one containing the LED with heat sink, and the other containing the re-emitting semiconductor construction layer and multilayer reflector(s). The two halves can be made separately, and then be joined or otherwise secured together. This construction technique can help simplify manufacturing and increase overall yields.
  • the microstructured surface can be characterized by a single set of linear v-shaped grooves or prisms, multiple intersecting sets of v-shaped grooves that define arrays of tiny pyramids, one or more sets of narrow ridges, and so forth.
  • a single set of linear v-shaped grooves or prisms multiple intersecting sets of v-shaped grooves that define arrays of tiny pyramids, one or more sets of narrow ridges, and so forth.
  • LP reflector 86 which has been embossed in the form of a concave ellipsoid or similar shape, directs UV excitation light directly from the LED onto the upper surface of re-emitting semiconductor construction layer 82, which surface faces the front of device 80.
  • the LED and re-emitting semiconductor construction layer are preferably disposed at the foci of the ellipsoid.
  • the visible light emitted by the re-emitting semiconductor construction layer is transmitted by LP reflector 86 and collected by the rounded front end of the device body to form the desired pattern or visible (preferably white) light.
  • long pass reflective filters are placed opposite the re-emitting semiconductor construction layer from the LED in order to recycle the LED excitation light back to the re-emitting semiconductor construction in order to improve system efficiency.
  • a long pass filter may be omitted if the LED emissions are in the visible spectrum and large amounts are needed to balance the re-emitting semiconductor construction color output.
  • a long pass filter that partially transmits the shortwave light such as e.g. blue light, can be used to optimize the angular performance of a blue-LED/yellow-re-emitting semiconductor construction system via the spectral angle shift that would pass more blue light at higher angles than at normal incidence.
  • the reflective polarizer allows light of a preferred polarization to be emitted, while reflecting the other polarization.
  • the re-emitting semiconductor construction layer and other film components known in the art can depolarize the polarized light reflected by reflective polarizer, and either by the reflection of the re-emitting semiconductor construction layer, or re-emitting semiconductor construction layer in combination with the multilayer reflector, light can be recycled and increase the polarized light brightness of the solid state light device (LED).
  • Suitable reflective polarizers include, for example, cholesteric reflective polarizers, cholesteric reflective polarizers with a 1 A wave retarder, DBEF reflective polarizer available from 3M Company or DRPF reflective polarizer also available from 3M
  • the non-planar multilayer reflector can be positioned in any usable configuration with the LED, as described herein.
  • the non-planar multilayer reflector is positioned between the re-emitting semiconductor construction and the LED (see e.g., Fig. 17).
  • the re-emitting semiconductor construction is positioned between the non-planar multilayer reflector and the LED (see e.g., Figs. 15, 16).
  • the non-planar multilayer reflector 224/324 can be configured to reflect UV or blue light and transmit at least a portion of the visible light spectrum such as green, yellow, or red light. In another illustrative embodiment, the non-planar multilayer reflector 224/324 can be configured to reflect UV, blue or green light and transmit at least a portion of the visible light spectrum such as yellow or red light.
  • the re-emitting semiconductor construction 222/322 is capable of emitting visible light when illuminated with excitation light emitted from an LED 212/312.
  • the re- emitting semiconductor construction material can be any useable thickness.
  • non-planar multilayer reflector 426 is a hemispherical concave shape facing toward the LED 412. Such a design allows light emitted by the LED 412 to strike the non-planar multilayer reflector 426 at a normal or a near normal incidence angle.
  • the non-planar geometry of the multilayer reflector 426 allows substantially all short wave light to pass through the non-planar multilayer reflector 426 no matter what side or direction it emanates from the LED 412.
  • a re-emitting semiconductor construction 522 is shown disposed between the first non-planar polymeric multilayer reflector 524 and the second non-planar polymeric multilayer reflector 526.
  • the re-emitting semiconductor construction 522 is described above.

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Abstract

La présente invention concerne un dispositif comprenant : a) une DEL capable d'émettre de la lumière à une première longueur d'onde ; b) une construction semi-conductrice réémettrice qui comprend un puits de potentiel non situé dans une jonction pn ; et c) un réflecteur positionné pour réfléchir la lumière émise par la DEL sur la construction semi-conductrice réémettrice. En variante, le dispositif comprend : a) une DEL capable d'émettre de la lumière à une première longueur d'onde ; b) une construction semi-conductrice réémettrice capable d'émettre de la lumière à une seconde longueur d'onde qui comprend au moins un puits de potentiel non situé dans une jonction pn ; et c) un réflecteur qui transmet la lumière à ladite première longueur d'onde et réfléchit au moins une partie de la lumière émise à ladite seconde longueur d'onde. En variante, le dispositif comprend un module semi-conducteur comprenant un premier puits de potentiel situé dans une jonction pn qui comprend une DEL capable d'émettre une première longueur d'onde, et un second puits de potentiel non situé dans une jonction pn qui comprend une construction semi-conductrice réémettrice.
EP07798368.2A 2006-06-12 2007-06-11 Dispositif à del avec construction semi-conductrice réémettrice et réflecteur Withdrawn EP2033237A4 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US80453806P 2006-06-12 2006-06-12
PCT/US2007/070853 WO2007146863A1 (fr) 2006-06-12 2007-06-11 Dispositif à del avec construction semi-conductrice réémettrice et réflecteur

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EP2033237A1 true EP2033237A1 (fr) 2009-03-11
EP2033237A4 EP2033237A4 (fr) 2013-10-02

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EP07798368.2A Withdrawn EP2033237A4 (fr) 2006-06-12 2007-06-11 Dispositif à del avec construction semi-conductrice réémettrice et réflecteur

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EP (1) EP2033237A4 (fr)
JP (1) JP2009540617A (fr)
KR (1) KR20090018627A (fr)
CN (1) CN101467273B (fr)
TW (1) TW200810156A (fr)
WO (1) WO2007146863A1 (fr)

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DE102008012316B4 (de) 2007-09-28 2023-02-02 OSRAM Opto Semiconductors Gesellschaft mit beschränkter Haftung Halbleiterlichtquelle mit einer Primärstrahlungsquelle und einem Lumineszenzkonversionselement
JP5519000B2 (ja) 2009-04-30 2014-06-11 ゼルティック エステティックス インコーポレイテッド 脂肪が豊富な皮下細胞から熱を除去するためのデバイス、システム、及び方法
DE102013212372A1 (de) * 2013-06-27 2014-12-31 Robert Bosch Gmbh Optische Baueinheit
CN105865668B (zh) * 2015-01-20 2019-12-10 北京纳米能源与系统研究所 压力传感成像阵列、设备及其制作方法
WO2021066050A1 (fr) * 2019-10-02 2021-04-08 富士フイルム株式会社 Dispositif de rétroéclairage et d'affichage à cristaux liquides
JP2024044397A (ja) * 2022-09-21 2024-04-02 株式会社トプコン 植物センサ
JP2024044396A (ja) * 2022-09-21 2024-04-02 株式会社トプコン 植物センサ

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JP3559446B2 (ja) * 1998-03-23 2004-09-02 株式会社東芝 半導体発光素子および半導体発光装置
JP3358556B2 (ja) * 1998-09-09 2002-12-24 日本電気株式会社 半導体装置及びその製造方法
US6853012B2 (en) * 2002-10-21 2005-02-08 Uni Light Technology Inc. AlGaInP light emitting diode
US7091653B2 (en) * 2003-01-27 2006-08-15 3M Innovative Properties Company Phosphor based light sources having a non-planar long pass reflector
US7136408B2 (en) * 2004-06-14 2006-11-14 Coherent, Inc. InGaN diode-laser pumped II-VI semiconductor lasers
US7223998B2 (en) * 2004-09-10 2007-05-29 The Regents Of The University Of California White, single or multi-color light emitting diodes by recycling guided modes
US7045375B1 (en) * 2005-01-14 2006-05-16 Au Optronics Corporation White light emitting device and method of making same

Also Published As

Publication number Publication date
WO2007146863A1 (fr) 2007-12-21
JP2009540617A (ja) 2009-11-19
CN101467273B (zh) 2012-05-09
KR20090018627A (ko) 2009-02-20
CN101467273A (zh) 2009-06-24
TW200810156A (en) 2008-02-16
EP2033237A4 (fr) 2013-10-02

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