Abstract: Isoelectronic co-doping of semiconductor compounds and alloys with deep acceptors and deep donors is used to decrease bandgap, to increase concentration of the dopant constituents in the resulting alloys, and to increase carrier mobilities lifetimes. Group III-V compounds and alloys, such as GaAs and GaP, are isoelectronically co-doped with, for example, N and Bi, to customize solar cells, thermal voltaic cells, light emitting diodes, photodetectors, and lasers on GaP, InP, GaAs, Ge, and Si substrates. Isoelectronically co-doped Group II-VI compounds and alloys are also included.

Abstract: A semiconductor device is provided having n-type device layers of III-V nitride having donor dopants such as germanium (Ge), silicon (Si), tin (Sn), and/or oxygen (O) and/or p-type device layers of III-V nitride having acceptor dopants such as magnesium (Mg), beryllium (Be), zinc (Zn), and/or cadmium (Cd), either simultaneously or in a doping superlattice, to engineer strain, improve conductivity, and provide longer wavelength light emission.

Abstract: On an n-GaP substrate transparent against a radiation light of an InAlGaP based semiconductor element, a lattice distortion relaxation layer, a clad layer 13, an active layer, and a clad layer are created with InAlGaP. On top of the layers, there is formed an InxGa1−xP current diffusion layer with In composition ratio x equal to (0<X<1). Through these steps, uneven depth on the crystal surface is decreased and crystal defect concentration is lowered. In addition, the energy gap of the current diffusion layer is made larger than the energy gap of the active layer, so that the GaP substrate and the uppermost InGaP current diffusion layer become transparent against a radiation light from the active layer, resulting in increased light emitting efficiency. Further, simple formation of layers from the lattice distortion relaxation layer to the current diffusion layer in sequence enables reduction of the production costs.

Abstract: The invention has for its object to provide an EL phosphor multilayer thin film and EL device which can emit light with improved luminance. This object is achieved by the provision of an EL phosphor multilayer thin film wherein a phosphor thin film and a dielectric thin film are stacked one upon another. The phosphor thin film comprises a matrix material containing as a main component at least one compound selected from an alkaline earth thioaluminate, an alkaline earth thiogallate and an alkaline earth thioindate, and an rare earth element as a luminescent center, and the dielectric thin film comprises an alkaline earth oxide. There is also provided an EL device comprising such an EL phosphor multilayer thin film.

Abstract: A nitride semiconductor light emitting device includes a worked substrate including grooves and lands formed on a main surface of a nitride semiconductor substrate, a nitride semiconductor underlayer covering the grooves and the lands of the worked substrate and a nitride semiconductor multilayer emission structure including an emission layer including a quantum well layer or both a quantum well layer and a barrier layer in contact with the quantum well layer between an n-type layer and a p-type layer over the nitride semiconductor underlayer, while the width of the grooves is within the range of 11 to 30 &mgr;m and the width of the lands is within the range of 1 to 20 &mgr;m.

Abstract: An n-GaN layer is provided as an emitter layer for supplying electrons. A non-doped (intrinsic) AlxGa1−xN layer (0≦x≦1) having a compositionally graded Al content ratio x is provided as an electron transfer layer for transferring electrons toward the surface. A non-doped AlN layer having a negative electron affinity (NEA) is provided as a surface layer. Above the AlN layer, a control electrode and a collecting electrode are provided. An insulating layer formed of a material having a larger electron affinity than that of the AlN layer is interposed between the control electrode and the collecting electrode. This provides a junction transistor which allows electrons injected from the AlN layer to conduct through the conduction band of the insulating layer and then reach the collecting electrode.

Abstract: A semiconductor device is provided having n-type device layers of III-V nitride having donor dopants such as germanium (Ge), silicon (Si), tin (Sn), and/or oxygen (O) and/or p-type device layers of III-V nitride having acceptor dopants such as magnesium (Mg), beryllium (Be), zinc (Zn), and/or cadmium (Cd), either simultaneously or in a doping superlattice, to engineer strain, improve conductivity, and provide longer wavelength light emission.

Abstract: A high emission intensity group-III nitride semiconductor light-emitting device obtained by eliminating crystal lattice mismatch with substrate crystal and using a gallium nitride phosphide-based light emitting structure having excellent crystallinity. A gallium nitride phosphide-based multilayer light-emitting structure is formed on a substrate via a boron phosphide (BP)-based buffer layer. The boron phosphide-based buffer layer is preferably grown at a low temperature and rendered amorphous so as to eliminate the lattice mismatch with the substrate crystal. After the amorphous buffer layer is formed, it is gradually converted into a crystalline layer to fabricate a light-emitting device while keeping the lattice match with the gallium nitride phosphide-based light-emitting part.

Abstract: Organic light emitting devices are described wherein the emissive layer comprises a host material containing a fluorescent or phosphorescent emissive molecule, which molecule is adapted to luminesce when a voltage is applied across the heterostructure, wherein an intersystem crossing molecule of optical absorption spectrum matched to the emission spectrum of the emissive molecule enhances emission efficiency.

Abstract: On an n-GaP substrate transparent against a radiation light of an InAlGaP based semiconductor element, a lattice distortion relaxation layer, a clad layer 13, an active layer, and a clad layer are created with InAlGaP. On top of the layers, there is formed an InxGa1-xP current diffusion layer with In composition ratio x equal to (0<X<1). Through these steps, uneven depth on the crystal surface is decreased and crystal defect concentration is lowered. In addition, the energy gap of the current diffusion layer is made larger than the energy gap of the active layer, so that the GaP substrate and the uppermost InGaP current diffusion layer become transparent against a radiation light from the active layer, resulting in increased light emitting efficiency. Further, simple formation of layers from the lattice distortion relaxation layer to the current diffusion layer in sequence enables reduction of the production costs.

Abstract: The extraction efficiency of a light emitting device can be improved by making the absorbing device layers as thin as possible. The internal quantum efficiency decreases as the device layers become thinner. An optimal active layer thickness balances both effects. An AlGaInP LED includes a substrate and device layers including an AlGaInP lower confining layer of a first conductivity type, an AlGaInP active region of a second conductivity type, and an AlGaInP upper confining layer of a second conductivity type. The absorbance of the active region is at least one fifth of the total absorbance in the light-emitting device. The device optionally includes at least one set-back layers of AlGaInP interposing one of confining layer and active region. The p-type upper confining layer may be doped with oxygen improve the reliability.

Abstract: A light emitting diode includes a substrate, a light emitting layer, a first cladding layer having a first conductivity type and an energy gap greater than an energy gap of the light emitting layer, a second cladding layer having a second conductivity type and an energy gap greater than an energy gap of the light emitting layer, and an intermediate barrier layer having the same conductivity type as the conductivity type of the light emitting layer but different from the conductivity type of the first or second cladding layer, and having an energy gap less than the energy gap of the first or second cladding layer but greater than the energy gap of the light emitting layer. The light emitting diode has a double heterostructure such that the light emitting layer is interposed between the first and second cladding layer. The intermediate barrier layer is disposed between the light emitting layer and the first cladding layer and/or between the light emitting layer and the second cladding layer.

Abstract: A light-emitting semiconductor device (10) consecutively includes a sapphire substrate (1), an AlN buffer layer (2), a silicon (Si) doped GaN n+-layer (3) of high carrier (n-type) concentration, a Si-doped (Alx3Ga1−x3)y3In1−y3N n+-layer (4) of high carrier (n-type) concentration, a zinc (Zn) and Si-doped (Alx2Ga1−x2)y2In1−y2N emission layer (5), and a Mg-doped (Alx1Ga1−x1)y1In1−y1N p-layer (6). The AlN layer (2) has a 500 Å thickness. The GaN n+-layer (3) has about a 2.0 &mgr;m thickness and a 2×1018/cm3 electron concentration. The n+-layer (4) has about a 2.0 &mgr;m thickness and a 2×1018/cm3 electron concentration. The emission layer (5) has about a 0.5 &mgr;m thickness. The p-layer 6 has about a 1.0 &mgr;m thickness and a 2×1017/cm3 hole concentration. Nickel electrodes (7, 8) are connected to the p-layer (6) and n+-layer (4), respectively. A groove (9) electrically insulates the electrodes (7, 8).

Abstract: The invention relates to a semiconductor electro-optical monolithic component. The component is made up of at least two sections, each of which has a respective waveguide, the waveguides being etched in the form of ridges, disposed in line, and buried in a cladding layer. The sections are electrically isolated from one other by a resistive zone. At the interface between two sections, the waveguides are locally of an extended width not less than the width of the resistive zone.

Abstract: The present invention provides an epitaxial wafer having compound semiconductor epitaxial layer provided on a substrate, a total thickness of a portion of the compound semiconductor epitaxial layers comprises Ga, As and P as constituent elements being not less than 80 &mgr;m and in the epitaxial layer a low carrier concentration region with a carrier concentration of from 0.5 to 9×1015 cm−3 doped with nitrogen being formed.

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: Nitrogen-containing III-V alloy semiconductor materials have both a conduction band offset .DELTA.Ec and a valence band offset .DELTA.Ev large enough for the practical applications to light emitting devices. The semiconductor materials are capable of providing laser diodes, having excellent temperature characteristics with emission wavelengths in the red spectral region and of 600 nm or smaller, and high brightness light emitting diodes with emission wavelengths in the visible spectral region. The light emitting device is fabricated on an n-GaAs substrate, which has the direction normal to the substrate surface is misoriented by 15.degree. from the direction normal to the (100) plane toward the [011] direction. On the substrate, there disposed by MOCVD, for example, are an n-GaAs buffer layer, an n-(Al.sub.0.7 Ga.sub.0.3).sub.0.51 In.sub.0.49 P cladding layer, an (Al.sub.0.2 Ga.sub.0.8).sub.0.49 In.sub.0.51 N.sub.0.01 P.sub.0.99 active layer, a p-(Al.sub.0.7 Ga.sub.0.3).sub.0.51 In.sub.0.

Abstract: A light-emitting semiconductor device (10) consecutively includes a sapphire substrate (1), an AlN buffer layer (2), a silicon (Si) doped GaN n.sup.+ -layer (3) of high carrier (n-type) concentration, a Si-doped (Al.sub.x3 Ga.sub.1-x3).sub.y3 In.sub.1-y3 N n.sup.+ -layer (4) of high carrier (n-type) concentration, a zinc (Zn) and Si-doped (Al.sub.x2 Ga.sub.1-x2).sub.y2 In.sub.1-y2 N emission layer (5), and a Mg-doped (Al.sub.x1 Ga.sub.1-x1).sub.y1 In.sub.1-y1 N p-layer (6). The AlN layer (2)--is 500 .ANG. in thickness. The GaN N.sup.+ -layer (3) is about 2.0 .mu.m in thickness and has an electron concentration of about 2.times.10.sup.18 /cm.sup.3. The n.sup.+ -layer (4) is about 2.0 .mu.m in thickness and has an electron concentration of about 2.times.10.sup.18 /cn.sup.3. The emission layer (5) is about 0.5 .mu.m in thickness. The p-layer 6 is about 1.0 .mu.m in thickness and has a hole concentration of about 2.times.10.sup.17 /cm.sup.3. Nickel electrodes (7, 8) are connected to the p-layer (6) and n.sup.

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: On a first cladding layer formed of n-type Al.sub.0.7 Ga.sub.0.3 P, an active region having a staggered-type (type II) heterojunction superlattice structure is disposed. The active region includes 50 light emitting layers formed of Al.sub.0.1 Ga.sub.0.9 P doped with nitrogen and 50 barrier layers formed of Al.sub.0.7 Ga.sub.0.3 P. The 50 light emitting layers and the 50 barrier layers formed of such materials are stacked alternately to form 50 pairs. On the active region, a second cladding layer formed of Al.sub.0.1 Ga.sub.0.9 P is disposed. In the formation of the active layers the composition of the light emitting layer and the barrier layer end the thickness of the barrier layer are controlled so that the isoelectronic level in the light emitting layer and the quantum level in the barrier layer will fulfill the resonance conditions.

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 method of providing shallow acceptor and donor energy levels to produce higher conductivity semiconductor materials, relies on the coulombic pairing of donor and acceptor elements. One exemplary embodiment is applied to create shallow acceptor levels in the III-V nitride materials via the coulombic pairing of group I elements which, in principle, act as double acceptors occupying metal lattice sites with group IV or group VI elements which act as single donors occupying metal or nitrogen lattice sites, respectively. The resulting pairs act as single acceptors with an energy level much closer to the valence band edge than that of either the first or second level of the group I element acceptors in their unpaired state. This approach, when optimized, can result in creating acceptor levels much shallower than the Mg acceptors currently used to make p-type GaN and its alloys.

Abstract: On a first cladding layer formed of n-type Al.sub.0.7 Ga.sub.0.3 P, an active region having a staggered-type (type II) heterojunction superlattice structure is disposed. The active region includes 50 light emitting layers formed of Al.sub.0.1 Ga.sub.0.9 P doped with nitrogen and 50 barrier layers formed of Al.sub.0.7 Ga.sub.0.3 P. The 50 light emitting layers and the 50 barrier layers formed of such materials are stacked alternately to form 50 pairs. On the active region, a second cladding layer formed of Al.sub.0.1 Ga.sub.0.9 P is disposed. In the formation of the active layer, the composition of the light emitting layer and the barrier layer and the thickness of the barrier layer are controlled so that the isoelectronic level in the light emitting layer and the quantum level in the barrier layer will fulfill the resonance conditions.

Abstract: In an epitaxial wafer of gallium arsenide phosphide, a single crystal substrate is provided thereon with a gallium arsenide phosphide layer with a varying mixed crystal ratio, a gallium arsenide phosphide layer with a constant mixed crystal ratio, and a nitrogen-doped gallium arsenide phosphide layer with a constant mixed crystal ratio. The nitrogen-doped gallium arsenide phosphide layer with a constant mixed crystal ratio has a carrier concentration of 3.times.10.sup.15 cm.sup.-3 or less.

Abstract: n-type wide bandgap semiconductors grown on a p-type layer to form hole injection pn heterojunctions and methods of fabricating the same. In a preferred embodiment, a p-type gallium nitride substrate is used. A first layer, such as a magnesium zinc sulfide layer Mg.sub.x Zn.sub.1-x S is then deposited. Thereafter, a second layer such as an n-type zinc sulfide layer is deposited. The magnesium zinc sulfide layer forms an electron blocker layer, and preferably is adequately thick to prevent significant tunneling of electrons there through. Thus, the primary charge flow across the heterojunction is by way of holes injected into the n-type zinc sulfide region from the p-type gallium nitride region, resulting in electron-hole recombination in the zinc sulfide region to provide light emission in the wide bandgap zinc sulfide material. Alternate embodiments are disclosed.

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 GaP red light emitting diode (LED) which is free from a problem of luminance reduction comprises an n-type GaP epitaxial layer grown on an n-type GaP substrate, and a p-type GaP epitaxial layer grown on the n-type Gap epitaxial layer, wherein the n-type epitaxial layer has an Si concentration of not more than 5.times.10.sup.17 atoms/cc and an S concentration of not more than 1.times.10.sup.18 atoms/cc.

Abstract: A semiconductor sensor detects the existence of liquified gases by immersion or approaching the liquid. A high signal amplitude of the sensor permits a simple signal evaluation of high reliability. The sensor permits the realization of filling level measuring devices or level control devices for liquified gases.

Abstract: A light-emitting device in which the increase in the intensity of the emitted light is linear with respect to the increase in current, thereby facilitating current-based control of the light intensity. In the device, this is achieved by providing a high-resistance region, or a furrow, between the electrode on the semiconductor surface and the portion of the device p-n junction that is exposed on the surface.