Abstract: A gallium nitride-based III-V Group compound semiconductor device has a gallium nitride-based III-V Group compound semiconductor layer provided over a substrate, and an ohmic electrode provided in contact with the semiconductor layer. The ohmic electrode is formed of a metallic material, and has been annealed.

Abstract: In a nitride compound semiconductor light emitting device, an In.sub.0.3 Ga.sub.0.7 N/GaN multi-quantum well active layer 105 or an In.sub.0.1 Ga.sub.0.9 N/GaN multi-quantum well adjacent layer 104 is made as a saturable absorptive region so that self-pulsation occurs there. Thus, the device ensures self-pulsation with a high probability with a simple structure, and satisfies requirements for use as an optical head for reading data from an optical disc.

Abstract: An optoelectronic device (10) formed in a chip of an indirect bandgap semiconductor material such as silicon is disclosed and claimed. The device comprises a visibly exposed highly doped n.sup.+ region (16) embedded at the surface of an oppositely doped epitaxial layer (14), to form a first junction region (15) closed to the surface of the epitaxial layer. When the junction region is reverse biased to beyond avalanche breakdown, the device acts as a light emitting device to the external environment. When it is reversed biased to just below avalanche breakdown it acts as a light detector. The device may further include a further junction region for generating or providing additional carriers in the first junction region, thereby to improve the performance of the device. This further junction can be multiplied to facilitate multi-input processing functions where the light emission from the first junction is a function of the electrical signals applied to the further junctions.

Abstract: A gallium nitride-based III-V Group compound semiconductor device has a gallium nitride-based III-V Group compound semiconductor layer provided over a substrate, and an ohmic electrode provided in contact with the semiconductor layer. The ohmic electrode is formed of a metallic material, and has been annealed.

Abstract: Provided by the present invention is a II-VI compound semiconductor based light emitting device which is suppressed in the propagation velocity of crystal defects at the time of current application, has a prolonged lifetime and can be readily mass produced. The device has a recombination region and non-recombination region of carriers which have been separated spatially each other in the plane of the active layer.

Abstract: A sapphire substrate, a buffer layer of undoped GaN and a compound semiconductor crystal layer successively formed on the sapphire substrate together form a substrate of a light emitting diode. A first cladding layer of n-type GaN, an active layer of undoped In.sub.0.2 Ga.sub.0.8 N and a second cladding layer successively formed on the compound semiconductor crystal layer together form a device structure of the light emitting diode. On the second cladding layer, a p-type electrode is formed, and on the first cladding layer, an n-type electrode is formed. In a part of the sapphire substrate opposing the p-type electrode, a recess having a trapezoidal section is formed, so that the thickness of an upper portion of the sapphire substrate above the recess can be substantially equal to or smaller than the thickness of the compound semiconductor crystal layer.

Abstract: Nitride-based semiconductor element comprises a first layer, a mask formed on the first layer and has a plurality of opening portions, a nitride-based compound semiconductor layer formed on the mask, the nitride-based compound semiconductor layer including a first region having threading dislocations produced in such a manner that, in approximately a middle portion between two adjacent ones of the plurality of opening portions in the mask, a plurality of dislocations extend in a vertical direction to a surface of the mask, and a second region which comprises portions other than the middle portions and free from the dislocations, and a desired element structure formed on the semiconductor layer.

Abstract: An optoelectronic device (10) formed in a chip of an indirect bandgap semiconductor material such as silicon is disclosed and claimed. The device comprises a visibly exposed highly doped n.sup.+ region (16) embedded at the surface of an oppositely doped epitaxial layer (14), to form a first junction region (15) closed to the surface of the epitaxial layer. When the junction region is reverse biased to beyond avalanche breakdown, the device acts as a light emitting device to the external environment. When it is reversed biased to just below avalanche breakdown it acts as a light detector. The device may further include a further junction region for generating or providing additional carriers in the first junction region, thereby to improve the performance of the device. This further junction can be multiplied to facilitate multi-input signal processing functions where the light emission from the first junction is a function of the electrical signals applied to the further junctions.

Abstract: An epitaxial wafer for a light-emitting diode includes an n-type GaP single-crystal substrate, and at least an n-type semiconductor epitaxial layer and a p-type semiconductor epitaxial layer formed on the substrate. The substrate has a boron concentration of not more than 1.times.10.sup.17 cm.sup.-3. A light-emitting diode is fabricated using the epitaxial wafer thus formed provided with electrodes.

Abstract: An organic light emitting diode having a lower electrode formed on a glass substrate, and an emissive layer and an upper electrode formed atop each other on the lower electrode. A thin insulating layer is disposed between the emissive layer and the lower or upper electrode. The thin insulating layer has a thickness within a range where tunneling occurs. The thin insulating layer is inserted between the emissive layer and electrode, so as to balance the injection of electrons a holes into the emissive layer.

Abstract: A surface-emitting semiconductor optical device is provided, which has a high external quantum efficiency and a high coupling efficiency with an optical fiber. This device has a multilayer device structure including an optical absorption layer formed by a semiconductor substrate, a semiconductor mirror layer, a first (n- or p-type) semiconductor cladding layer, a semiconductor active layer, a second (p- or n-type) semiconductor cladding layer, and a current spreading layer formed by a transparent and doped semiconductor wafer. These layers are stacked along a stacking direction of the device structure. The absorption layer is located at a first end of the body. The active layer is sandwiched between the first and second cladding layers. The mirror layer is located between the first cladding layer and the absorption layer, and serves to reflect the light generated by the active layer toward the current spreading layer.

Abstract: An epitaxial wafer for a GaP pure green light emitting diode includes an n-type single crystal GaP substrate formed in order thereon with a first n-type GaP epitaxial layer, a second n-type GaP epitaxial layer and a p-type GaP epitaxial layer. The p-type GaP epitaxial layer has a sulfur concentration of not greater than 1.times.10.sup.17 cm.sup.31 3, the second n-type GaP epitaxial layer has a carrier concentration on a side thereof interfacing with the p-type GaP epitaxial layer of 0.5-5.times.10.sup.17 cm.sup.-3, and the p-type GaP epitaxial layer has a carrier concentration on a side thereof interfacing with the second n-type GaP epitaxial layer that is 1-10.times.10.sup.17 cm.sup.-3 and is not less than twice the carrier concentration of the second n-type GaP epitaxial layer on the side thereof interfacing with the p-type GaP epitaxial layer.

Abstract: A gallium nitride-based III-V Group compound semiconductor device has a gallium nitride-based III-V Group compound semiconductor layer provided over a substrate, and an ohmic electrode provided in contact with the semiconductor layer. The ohmic electrode is formed of a metallic material, and has been annealed.

Abstract: A semiconductor device requiring fewer masking steps to manufacture. The semiconductor device includes the following layers (from bottom up): (1) a substrate; (2) a gate electrode formed on a first portion of the substrate; (3) a first semiconductor layer overlying the gate electrode and a second portion of the substrate adjacent the first portion; (4) first and second spaced doped semiconductor layers provided on a surface of the first semiconductor layer and defining an exposed portion of the first semiconductor layer; (5) first and second insulating layer respectively provided on the first and second spaced doped semiconductor layers adjacent a periphery of the exposed portion of the first semiconductor layer; (6) a first electrode overlying and in contact with the doped semiconductor layer and the first insulating layer; and (7) a second electrode overlying and in contact with the second doped semiconductor layer and the second insulating layer.

Abstract: An epitaxial wafer for a GaP light-emitting element comprising an n-type GaP buffer layer, n-type GaP layer, nitrogen-doped n-type GaP layer and p-type GaP layer grown sequentially on an n-type GaP single-crystal substrate, in which the sum concentration of Ti, V, Cr, Mn, Fe, Co, Ni, and Cu in the nitrogen-doped n-type GaP layer does not exceed 1.times.10.sup.15 cm.sup.-3, and the sum concentration of Ti, V, Cr, Mn, Fe, Co, Ni, and Cu in the buffer layer does not exceed 1.times.10.sup.16 cm.sup.-3. n-type and p-type electrodes are formed on the wafer which is then divided to form GaP light-emitting elements.

Abstract: A photo diode in which an optical absorption layer and a p-type semiconductor layer neighboring on each other are designed to be at almost the same valence band level (their offset not exceeding 0.05 eV). Preferably the optical absorption layer is a GaInAsP layer with an absorption edge wavelength of 1.65 to 1.55 .mu.m, and the p-type semiconductor layer and lattice-matching with the preceding semiconductor layer are each an AlGaInAs layer with an absorption edge wavelength of 1.55 to 1.30 .mu.m remaining shorter than that of the optical absorption layer.

Abstract: A gallium nitride-based III-V Group compound semiconductor device has a gallium nitride-based III-V Group compound semiconductor layer provided over a substrate and an ohmic electrode provided in contact with the semiconductor layer. The ohmic electrode is formed of a metallic material, and has been annealed.

Abstract: A surface-emitting AlGaInP LED is disclosed.

Abstract: The invention includes a Group III-V compound semiconductor that comprises (1) a thin crystal film of A.sub.1.sup.III As.sub.w P.sub.1-w, wherein A.sub.1.sup.III represents a Group III element with Al composition of less than 0.3, 0.5<w.ltoreq.1, formed on a semiconductor crystal substrate or on an epitaxial film grown on the substrate, a thin crystal film of B.sup.III As, wherein B.sup.III represents a Group III element with Al composition of not less than 0.45, formed on the A.sub.1.sup.III As.sub.w P.sub.1-w film, and a thin film of C.sub.1.sup.III As.sub.x P.sub.1-x, wherein C.sub.1.sup.III represents a Group III element with Al composition of less than 0.3, 0.ltoreq.x 0.5, formed on the B.sup.III As film; or (2) a thin film of A.sub.2.sup.III As.sub.u P.sub.1-u, wherein A.sub.2.sup.III represents a Group III element with In composition of not less than 0.3, 0.ltoreq.u.ltoreq.1, formed on a semiconductor crystal substrate or on an epitaxial film grown on the substrate, a thin crystal film of B.sup.

Abstract: A light emitting diode (LED) and resistors for varying the light intensity of the LED are formed on a single chip. Each of the LED portion and the resistor portion includes an active layer and a clad layer successively deposited on a substrate of the chip. The substrate may be doped with one of P-type dopant and N-type dopant and the clad layer with the other of P and Y-type dopants. A first and second electrodes are formed on an exposed surface of the substrate and the clad layer of the LED portion respectively. A plurality of resistor electrodes are formed on the clad layer of the resistor portion. It is preferable to have different spacing between the resistor electrodes to form variable resistances.

Abstract: In a light emitting device made of a group II-VI semiconductor, a P-type interface film including one or two layers is formed between the positive electrode and the uppermost P-type layer of the group II-VI semiconductor film, to make the energy band increase in steps from the electrode to the semiconductor film, thereby realizing a structure where the current flows at a low voltage. The II-VI semiconductor film is MBE-grown at a substrate temperature of 350.degree. C. or below. The P-type interface film is formed to have a carrier concentration of 10.sup.19 /cm.sup.3 or above by MBE growth at a substrate temperature lower than or equal to the substrate temperature at which the semiconductor film is formed.

Abstract: A semiconductor light-emitting element has a crystal layer formed from aluminum of a high mol ratio of 60% or greater on the light producing surface. In the semiconductor light-emitting element, a conductive crystal with aluminum of a mol ratio of 50% or less, or a conductive crystal containing no aluminum is formed on the high aluminum crystal layer.

Abstract: An epitaxial layer(s) of compound semiconductor alloy doped with nitrogen and represented by the formula (Al.sub.x Ga.sub.1-x).sub.y In.sub.1-y P (0<x.ltoreq.1, 0<y.ltoreq.1) is formed on a compound semiconductor single crystal substrate composed of an element(s) from Group III and an element(s) from Group V in the periodic table by means of the metalorganic vapor phase epitaxy method (MOVPE method), while controlling the amount of the organic aluminum compound introduced. The organic aluminum compound is, for example, trimethyl aluminum (TMAl). The nitrogen-doped epitaxial layer is, for example, an active layer composed of said compound semiconductor alloy which has a band gap of 2.30 eV or larger and also has an alloy composition of an indirect transition area or similar to it.

Abstract: A light emitting device has an indium gallium arsenide phosphide luminescent layer between a first clad layer of n-type indium phosphide and a second clad layer of p-type indium phosphide, and a strained barrier layer of p-type indium aluminum arsenide is inserted between the luminescent layer and the second clad layer so as to increase the potential barrier therebetween, thereby improving the luminous efficiency and the saturation point of the light output.

Abstract: There are disclosed two types of gallium nitride LED having the pn junction. An LED of gallium nitride compound semiconductor (Al.sub.x Ga.sub.1-x N, where 0.ltoreq.x<1) comprises an n-layer; a p-layer which exhibits p-type conduction upon doping with p-type impurities and irradiation with electron rays, the p-layer joining to the n-layer; a first electrode for the n-layer so as to join to the n-layer, passing through a hole formed in the p-layer which extends from the p-layer to the n-layer; and a second electrode for the p-layer which is formed in a region which is separated by a groove formed in the p-layer so as to extend from the upper surface of the p-layer to said n-layer.

Abstract: AlN is added to a SiC light emitting layer of an optical semiconductor device in a molecular state, and an association of AlN is formed between crystal lattice points, which are close to each other in said light emitting layer. Said association is largely different from said SiC in degree of electron negativity so that said association traps a carrier in said light emitting layer, and forms an exciton.

Abstract: A semiconductor light emitting element with a high light-emitting efficiency, which is constituted in such a way that, of the composition of its GaN and AlN epitaxial layer, part of N is substituted by P, thus ensuring good lattice-matching with the substrate crystal, ZnO.

Abstract: A device for generating pulses of radio frequency energy in response to pulses of laser light in which a circular wafer of GaAs has metallized annular layers ohmically bonded to the wafer by epitaxial GaAs layers, and an epitaxial layer of AlGaAs in the center of one of the annular epitaxial layers through which laser light is to be directed, there being a plurality of apertures in the metallized layer in contact with the AlGaAs epitaxial layer. In addition, an AlGaAs epitaxial layer may be formed opposite the first AlGaAs layer and an optical fiber is brought into contact with it so that laser light can be introduced at both sides of the wafer.

Abstract: A high speed semiconductor pinch rectifier attains low forward voltage drop and low reverse leakage current by utilizing depletion region pinch-off of conduction channels in a high-resistivity region. In a preferred form, the pinch rectifier additionally utilizes a Schottky barrier contact so as to facilitate device fabrication.

Abstract: A device for radiating pulses of radio frequency energy in response to pulses of laser light in which a metal layer is ohmically bonded to one side of a substrate of semiconductor material and an antenna is ohmically bonded to the other side of the substrate, there being at least one aperture in the metal layer for permitting laser light to reach the disk.