Patent•
Gallium nitride-type semiconductor device
25 May 1999-
TL;DR: A GaN/GaN LED has a shape of a equilateral triangle, parallelogram, trapezoid, equilateral hexagon or rhombus as discussed by the authors, where the cleavage planes on two ends and two sides of the LED are straight.
Abstract: GaN-type LED or LD made on a (0001)GaN single crystal substrate having natural cleavage planes on sides. A GaN/GaN LED has a shape of a equilateral triangle, parallelogram, trapezoid, equilateral hexagon or rhombus. A GaN/GaN LD has a shape of a parallelogram with cleavage planes on two ends and two sides. Another GaN/GaN LD has a shape of a square with cleavage planes on two ends.
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Patent•
28 Mar 2008
TL;DR: In this paper, a light-emitting diode package is described, consisting of a package body having a cavity, a light emitting diode chip having a plurality of light emitting cells connected in serial with each other, and a fluorescent body for converting the wavelength of light emitted by the light emitting diodes.
Abstract: Disclosed is a light-emitting diode package, comprising: a package body having a cavity; a light-emitting diode chip having a plurality of light-emitting cells connected in serial with each other; a fluorescent body for converting the wavelength of light emitted by the light-emitting diode chip; and a pair of lead electrodes. The light-emitting cells are connected together in series between the pair of lead electrodes.
553 citations
Patent•
27 Mar 2014
TL;DR: By doping an organic compound functioning as an electron donor (hereinafter referred to as donor molecules) into an organics layer contacting a cathode, donor levels can be formed between respective LUMO (lowest unoccupied molecular orbital) levels between the cathode and the organic compound layer, and therefore electrons can be injected from the cathodes, and transmission of the injected electrons can also be performed with good efficiency as discussed by the authors.
Abstract: By doping an organic compound functioning as an electron donor (hereinafter referred to as donor molecules) into an organic compound layer contacting a cathode, donor levels can be formed between respective LUMO (lowest unoccupied molecular orbital) levels between the cathode and the organic compound layer, and therefore electrons can be injected from the cathode, and transmission of the injected electrons can be performed with good efficiency. Further, there are no problems such as excessive energy loss, deterioration of the organic compound layer itself, and the like accompanying electron movement, and therefore an increase in the electron injecting characteristics and a decrease in the driver voltage can both be achieved without depending on the work function of the cathode material.
236 citations
Patent•
26 May 2015
TL;DR: In this article, a wafer-level light emitting diode (LED) package and a method of fabricating the same is described. But the method is not suitable for the fabrication of a large number of LEDs.
Abstract: Exemplary embodiments of the present invention provide a wafer-level light emitting diode (LED) package and a method of fabricating the same. The LED package includes a semiconductor stack including a first conductive type semiconductor layer, an active layer, and a second conductive type semiconductor layer; a plurality of contact holes arranged in the second conductive type semiconductor layer and the active layer, the contact holes exposing the first conductive type semiconductor layer; a first bump arranged on a first side of the semiconductor stack, the first bump being electrically connected to the first conductive type semiconductor layer via the plurality of contact holes; a second bump arranged on the first side of the semiconductor stack, the second bump being electrically connected to the second conductive type semiconductor layer; and a protective insulation layer covering a sidewall of the semiconductor stack.
223 citations
Patent•
25 Jan 2002TL;DR: Light emitting diodes include a substrate having first and second opposing faces and that is transparent to optical radiation in a predetermined wavelength range and patterned to define, in cross-section, a plurality of pedestals that extend into the substrate from the first face towards the second face.
Abstract: Light emitting diodes include a substrate having first and second opposing faces and that is transparent to optical radiation in a predetermined wavelength range and that is patterned to define, in cross-section, a plurality of pedestals that extend into the substrate from the first face towards the second face. A diode region on the second face is configured to emit light in the predetermined wavelength range, into the substrate upon application of voltage across the diode region. A mounting support on the diode region, opposite the substrate is configured to support the diode region, such that the light that is emitted from the diode region into the substrate, is emitted from the first face upon application of voltage across the diode region. The first face of the substrate may include therein a plurality of grooves that define the plurality of triangular pedestals in the substrate. The grooves may include tapered sidewalls and/or a beveled floor. The first face of the substrate also may include therein an array of via holes. The via holes may include tapered sidewalls and/or a floor.
174 citations
Patent•
17 Jun 1999TL;DR: In this paper, a freestanding GaN single crystal substrate is made by the steps of preparing a (111) GaAs single-crystal substrate, forming a mask having periodically arranged windows on the substrate, making thin GaN buffer layers on the GaAs substrate in the windows of the mask, growing a GaN epitaxial layer on the buffer layers and the mask by an HVPE or an MOC.
Abstract: A freestanding GaN single crystal substrate is made by the steps of preparing a (111) GaAs single crystal substrate, forming a mask having periodically arranged windows on the (111) GaAs substrate, making thin GaN buffer layers on the GaAs substrate in the windows of the mask, growing a GaN epitaxial layer on the buffer layers and the mask by an HVPE or an MOC, eliminating the GaAs substrate and the mask away and obtaining a freestanding GaN single crystal substrate. The GaN single crystal has a diameter larger than 20 mm and a thickness more than 0.07 mm, being freestanding and substantially distortion-free.
165 citations
References
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TL;DR: In this paper, a GaN layer above the SiO2 mask area surrounding the window, corresponding to the lateral overgrowth, was nearly free of the threading dislocations and a high density was observed in the vicinity of GaN grown in the window regions.
Abstract: Epitaxially laterally overgrown GaN on sapphire was used to reduce the number of threading dislocations originating from the interface of the GaN epilayer with the sapphire substrate. The GaN layer above the SiO2 mask area surrounding the window, corresponding to the lateral overgrowth, was nearly free of the threading dislocations. A high density of threading dislocations was observed in the vicinity of GaN grown in the window regions. InGaN multi-quantum-well-structure laser diodes (LDs) grown on pure GaN substrates, which were fabricated by removing the sapphire substrate, were demonstrated. The LDs with an output power of 5 mW exhibited a lifetime of more than 290 h and an estimated lifetime of 10,000 h despite a relatively large threshold current density. The far-field pattern of the LDs with a cleaved mirror facet revealed single-mode emission without any interference effects.
253 citations
Patent•
[...]
TL;DR: A GaN single crystal having a full width at half-maximum of the double-crystal X-ray rocking curve of 5-250 sec and a thickness of not less than 80 μm was presented in this paper.
Abstract: A GaN single crystal having a full width at half-maximum of the double-crystal X-ray rocking curve of 5-250 sec and a thickness of not less than 80 μm, a method for producing the GaN single crystal having superior quality and sufficient thickness permitting its use as a substrate and a semiconductor light emitting element having high luminance and high reliability, comprising, as a substrate, the GaN single crystal having superior quality and/or sufficient thickness permitting its use as a substrate.
136 citations
TL;DR: In this article, the InGaN multi-quantum-well-structure laser diode (LD) was grown on a free-standing GaN substrate, which was obtained by removing the sapphire substrate.
Abstract: After obtaining an epitaxially laterally overgrown GaN on sapphire by the metalorganic chemical vapor deposition method, GaN growth was continued up to a thickness of 200 μm by a hydride vapor phase epitaxy method. The InGaN multi-quantum-well-structure laser diode (LD) was grown on a free-standing GaN substrate, which was obtained by removing the sapphire substrate. The LDs with cleaved mirror facets showed an output power as high as 160 mW under room-temperature continuous-wave (CW) operation. The fundamental transverse mode was observed up to an output power of 80 mW. The lifetime of the LDs at a constant output power of 5 mW was about 180 h under CW operation at an ambient temperature of 50 °C, due to a high threshold current density of 14 kA/cm2.
119 citations
Patent•
17 Sep 1996
TL;DR: In this paper, an amorphous insulator (4) is formed on a substrate (1; 1, 2, 3) and has windows where the substrate is exposed, and a compound semiconductor (5, 51, 52) containing at least nitrogen as a constituent is formed to form a semiconductor material.
Abstract: An amorphous insulator (4) is formed on a substrate (1; 1, 2, 3) and has windows where the substrate (1; 1, 2, 3) is exposed. On the exposed parts (40) of the substrate and the insulator (4), a compound semiconductor (5, 51, 52) containing at least nitrogen as a constituent is formed to form a semiconductor material (1, 5, 51, 52). A semiconductor device is fabricated by processing the semiconductor material (1, 5, 51, and 52) or a semiconductor material (6 and 7) formed on the semiconductor material (1, 5, 51, and 52).
111 citations
Patent•
17 May 1996TL;DR: In this article, an epitaxial growth layer composed of a III-V group nitride semiconductor is formed on an n-type 6H-SiC substrate having a {0001} crystal growth plane.
Abstract: A semiconductor light emitting device and a semiconductor laser device having an epitaxial growth layer composed of a III-V group nitride semiconductor. An AlN buffer layer, an n-type GaN intermediate layer, an n-type Al1-x GaX N cladding layer, an In1-Y GaY N active layer and a p-type Al1-X GaX N cladding layer, and a p-type GaN contact layer are successively formed on an n-type 6H--SiC substrate having a {0001} crystal growth plane. A p-side electrode is formed on the upper surface of the p-type GaN contact layer, and an n-side electrode is formed on the lower surface of the n-type 6H--SiC substrate, after which the n-type 6H--SiC substrate is cleaved along a {1120} plane to form a cavity facet.
43 citations