Abstract: The subject invention includes a far-infrared detector based on InSbBix1-x which operates 12 .mu.m at room temperature with an energy band gap as low as 0.13 eV (9.3 .mu.m) at 77K and 12 .mu.m at 300K. The subject invention may be prepared by growing epitaxial layers of InSbBi on InSb which is grown on a suitable substrate. The wavelength of absorption may be controlled through the variation of the Bi concentration in the InSbBi active layer.

Abstract: A photodetector which can be operated in two wavelength ranges and is comprised of two detectors (A, B) arranged one on top of the other. A Si Schottky diode forms detector A which absorbs light in a region .lambda.<0.9 .mu.m. Longer-waved light (1 .mu.m<.lambda.<2 .mu.m) is absorbed in detector B which is comprised of an Si/SiGe pn-diode. To increase the efficiency, detector B is made with an integrated resonator. A further increase of the efficiency of the photodetector is accomplished through the mounting of a Bragg reflector on the absorbing layer of detector B.

Abstract: A semiconductor light-emitting device involving the steps of: forming a first semiconductor layer; forming a light-emitting layer of superlattice structure by laminating a barrier layer being made of In.sub.Y1 Ga.sub.1-Y1 N (Y1.gtoreq.0) and a quantum well layer being made of In.sub.Y2 Ga.sub.1-Y1 N (Y2>Y1 and Y2>0) on the first semiconductor layer; and forming a second semiconductor layer on the light-emitting layer, an uppermost barrier layer, which will become an uppermost layer of the light-emitting layer, is made thicker than the other barrier layers. Further, at the time of forming the second semiconductor layer, an upper surface of such uppermost barrier layer is caused to disappear so that the thickness of the uppermost barrier layer becomes substantially equal to those of the other barrier layers.

Abstract: An opto-electronic device, such as a light-emitting diode, comprises a transparent high lateral conductivity current spreading layer 31 overlying a conventional p-n junction active region 10. The current spreading layer 31 comprises a multiple quantum-well heterostructure having a plurality of thin layers 33 of a material having a band-gap narrower than the band-gap of the active region disposed between layers 32 of a material having a band-gap greater than or equal to the band-gap of the active region 10, the wide band-gap layers 32 being more highly doped than said narrow band-gap layers 33. Quantum confinement occurs in the narrow band-gap layers 33, so that it becomes transparent to light emitted from the active region 10. Furthermore, the layers 33 of narrow band-gap material become highly conductive owing to charge carriers which have transferred from the more highly doped wide band-gap material layers 32.

Abstract: A InGaSb/GaSb strained-layer superlattices infrared photodetector in which the light-hole and heavy-hole are dispersed by the stress of the lattice mismatch, making the confined energy of the light hole and that of the heavy hole different. The wave function coupling of 1C-1HH is larger at near zero bias, thus the 1C-1HH is dominant. The wave function coupling of 1C-1LH is increased as reverse bias increases. When the reverse bias is high enough, the 1C-1HH transition becomes dominant. Because the transition energy of 1C-1HH and that of 1C-1LH are different, the modes of photodetector can be modulated by applying voltage.

Abstract: A luminescent semiconductor device comprises: an active layer composed of a Group II-VI semiconductor device which comprises at least one Group II element selected from the group consisting of zinc, magnesium, beryllium, cadmium, manganese and mercury, and at least one Group VI element selected from the group consisting of oxygen, sulfur, selenium and tellurium. the Group II-VI compound semiconductor forming said active layer contains at least one element selected from the group consisting of magnesium, beryllium and cadmium as the Group II element and tellurium as the Group VI element. At least one antidiffusion layer preventing diffusion of these elements from the active layer is provided on at least one surface of the active layer.

Abstract: Structure of a wide voltage operation regime double heterojunction bipolar transistor, specifically a modified InGaP/GaAs double heterojunction bipolar transistor featuring a very broad collector-emitter voltage operation range, an invention of high speed, low power consumption and high breakdown voltage rated microwave power transistor. Unique in the incorporation of In.sub.0.49 Ga.sub.0.51 P collector layer, GaAs delta-doping sheet and undoped GaAs spacer in the collector zone. The introduction of a spacer with a delta doping sheet into the effective base-collector heterojunction serves to eliminate potential spike from appearing at base-collector interfacing any more, thus effectively precludes electron blocking effect. In the emitter zone the inventive design comprises a five-period In.sub.0.49 Ga.sub.0.

Abstract: Dispose a fine metal particle on a semiconductor substrate. By heat-treating this in a vacuum, a constituent element of the semiconductor substrate is dissolved into the fine metal particle to form a solid solution, resulting in further formation of a homogeneous liquid phase (liquid droplet) composed of semiconductor-metal. By annealing this, the constituent element of the semiconductor substrate is precipitated from the semiconductor-metal liquid droplet. Thus, a fine projection composite structure comprising a semiconductor substrate, a semiconductor fine projection epitaxially grown selectively at an arbitrary position on the semiconductor substrate, and a metal layer disposed selectively on the semiconductor fine projection, can be obtained. The metal layer can be removed as demands arise. Such a fine projection composite structure possesses applicability in, for instance, an ultra-high integration semiconductor device or a quantum size device.

Abstract: A method is provided for determining the temperature of a semiconductor fabrication process in which a resistivity versus temperature calibration curve for a superlattice structure is created. A plurality of similar superlattice structures which include alternating layers of a conductor and a semiconductor may be annealed at different temperatures. The resistivity of each superlattice structure may then be measured after the superlattice structures have been cooled to room temperature in order to form the calibration curve. A similar superlattice structure may then be subjected to the temperature at which the semiconductor fabrication process is typically performed, causing the resistivity of the superlattice structure to change. Based on the resulting resistivity of the superlattice structure, the calibration curve may be used to determine the process temperature of the superlattice structure during the fabrication process.

Abstract: The present invention includes forming a conductive layer on a substrate. Portions of the conductive layer are removed using a first photoresist layer as a mask. A first oxide layer is formed over the conductive layer and the substrate, and an amorphous silicon layer is then formed on the first oxide layer. After annealing the amorphous silicon layer, thereby transforming amorphous silicon layer to a polysilicon layer, a second oxide layer is formed on the polysilicon layer. The second oxide layer is removed using a second photoresist layer as a mask. An amorphous silicon carbon layer is formed over the second oxide layer and the polysilicon layer, and a heavily-doped amorphous silicon carbon layer is formed on the amorphous silicon carbon layer.

Abstract: The invention concerns an InAs/GaSb superlattice infrared detector that is prepared on a GaSb or a GaAs substrate by low pressure organometaleic chemical vapor deposition. The thickness of well and barrier modulated in the superlattice is used to control the wavelength of absorption. As the superlattice is sandwiched by the Si-doped InAs layer, the wavelength of absorption is in the 8.about.14 .mu.m range. As the superlattice is sandwiched by the Zn-doped GaSb layer, the wavelength of absorption is in the 3.about.5 .mu.m range.

Abstract: Thermodynamically metastable skutterudite crystalline-structured compounds are disclosed having preselected stoichiometric compositions and superior and optimizable thermoelectric properties. The compounds are formed at low nucleation temperatures and satisfy the formula:M.sub.1-x M'.sub.4-y Co.sub.y M".sub.12wherein:M=any metal, metalloid, or mixture thereof, except for La, Ce, Pr, Nd, and Eu when x=0, and M'=Fe, Ru, or Os, and M"=Sb, P, or As;M'=Fe, Ru, Os, Rh, or mixture thereof;M"Sb, As, P, Bi, Ge.sub.0.5-w Se.sub.0.5+w, wherein w=0 to 0.5 or mixture thereof;x=0 to 1;y=0 to 4; andwherein M' and/or M" are doped or undoped. These compounds generally have the crystalline structure of a skutterudite, wherein the crystalline structure is cubic with 34 atoms in the unit-cell in the space group Im3. The M".sub.12 atoms occupy unit-cell sites 24(g), the M'.sub.4-y atoms form a cubic sublattice occupying unit-cell sites 8(c), and the M.sub.

Abstract: A cold-cathode emitter includes a high-voltage tank of a second conductivity that is formed in a substrate having a first conductivity. An emitter tip is integral with the tank and extends outwardly from the substrate. The tank forms either a drain region or a collector region of a transistor. A cold-cathode emitter device includes a drive transistor formed in a substrate of a first conductivity. The transistor includes an electron receive region of a second conductivity. An emitter tip is integral with the electron receive region and extends outwardly from the substrate.

Abstract: A semiconductor device includes a first semiconductor layer of a first conductivity type, a second semiconductor layer of the first conductivity type formed on the surface of the first semiconductor layer, the energy difference between the bottom of the conductive band and the vacuum level in the second semiconductor layer being smaller than that in the first semiconductor layer, a gate electrode formed above the second semiconductor layer with a gate insulating film interposed therebetween, and a pair of third semiconductor layers of the second conductivity type, being in contact with at least the first semiconductor layer and faced each other in a region of the surface of the first semiconductor layer, so that a channel region is formed under the gate electrode.

Abstract: The gallium nitride compound semiconductor light emitting element includes: a substrate; a first semiconductor multilayer structure including, at least, an active layer, a first cladding layer of a first conductivity type, and a second cladding layer of a second conductivity type, the first and second cladding layers sandwiching the active layer therebetween; a dry etching stop layer of the second conductivity type formed on the first semiconductor multilayer structure; and a second semiconductor multilayer structure formed on the dry etching stop layer.

Abstract: Heteroepitaxy of lattice-mismatched semiconductor materials such as GaAs (110) on silicon (102) is accomplished by formation of a defect annihilating grid (104) on the silicon (102) prior to the epitaxy of the GaAs (110).

Abstract: The optical semiconductor device comprises a multiple quantum well structure of an AlGaInAs system material formed on an InP semiconductor substrate. The multiple quantum well structure comprises a barrier layer of a below 1.0 .mu.m of PL wavelength and a below 4.5 nm of film thickness active layer alternately laid one on another. An above 0.5% compressive strain is applied to the active layer. Thus the AlGaInAs/InP system optical semiconductor can have good temperature characteristics.

Abstract: A semiconductor having enhanced acceptor activation is disclosed. The semiconductor comprises a ternary compound having a non-abruptly varying composition that is uniformly doped. The modulation of the chemical composition leads to a variation of the valence band energy. The modulation of the valence band results in a strong enhancement of the acceptor activation. A method for making a semiconductor having enhanced acceptor activation comprises two steps. They are (1) forming a ternary compound semiconductor having a non-abruptly varying composition, and (2) uniformly doping said semiconductor with a dopant. These two steps may be conducted simultaneously.

Abstract: A surface emission semiconductor laser device has a semiconductor laminate mirror constituted of a plurality of pairs of InGaAS/InAlP films epitaxially grown on a GaAs or InGaAs substrate and a laser element bonded to the laminate mirror. The InAlP films of the laminate mirror are lattice-matched or not lattice-matched due to the amount of Al in the InAlP films. The laminate mirror has a high relative refractive index between the InGaAs and InAlP films and thus has a high reflectance to thereby improve the emission efficiency of the surface emission laser device.

Abstract: A semiconductor laser has a multiple-quantum well (MQW) structure overlying a first III-V compound semiconductor. The MQW includes a plurality of layer combinations including a strained well layer and a strained barrier layer, which are formed in a cyclic order. An ultra-thin intermediate film made of the first III-V compound semiconductor and having a thickness corresponding to from monoatomic layer to ten atomic layer is interposed between each strained well layer and each strained barrier layer. The intermediate film functions for preventing formation of mixed crystal formed between the well layer and the barrier layer, thereby improving current density threshold and other characteristics of the semiconductor laser.

Abstract: This invention relates to the field of semiconductor devices. Silicon-based semiconductor devices ordinarily lack desirable optical properties because silicon's small, indirect band gap causes electrons to emit radiation with negligible quantum efficiency. This invention solves that problem by taking advantage of the change in the nature of the electron band gap when electron flow is confined within a one-dimensional channel known as a quantum wire. By biasing the junction between the quantum wire and the surrounding silicon support matrix with a voltage, a semiconductor device of this invention emits radiation of a variable and modulable wavelength, including visible light, as well as of a variable and modulable intensity. Alternatively, the workings of the device may be reversed such that it detects incoming radiation. Given its optical properties, such a device has numerous applications in the field of optoelectronics and integrated circuits.

Abstract: A structure of periodically varying density is provided, that acts as a phonon resonator for phonons capable of participating in phonon-electron interactions. Specifically, a phonon resonator that is resonant for phonons of appropriate momentum to participate in indirect radiative transitions and/or inter zone intervalley scattering events is provided. Preferably, the structure is an isotope superlattice, most preferably of silicon. The structure of the present invention has improved optical, electrical, and/or heat transfer properties. A method of preparing a the structure of the present invention is also provided.

Abstract: A group III-V type nitride compound semiconductor light-emitting device employing compound semiconductors the lattices of which are matched to each other and having a large band discontinuity value between the semiconductor layers is characterized in that it is a light-emitting device obtained by junction of a barrier layer and an active layer and that the active layer contains Nb. The present invention provides a group III-V type nitride compound semiconductor light-emitting device which has low threshold current and low threshold voltage characteristics.

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: Disclosed is a long-life GaN-based semiconductor device which is achieved by reducing the operating voltage of the semiconductor device comprising a GaN-based or a ZnSe-based compound semiconductor formed on a sapphire substrate and by preventing the electromigration of metal atoms from an electrode into compound semiconductor layers. The operating voltage of the GaN-based or ZnSe-based semiconductor device formed on a sapphire substrate or a SiC substrate can be greatly reduced by employing a ZnO layer doped with a significant amount of Al as a material for forming ohmic contact to p- or n- compound semiconductor layers. The long-life GaN-based semiconductor device can be attained by preventing electromigration of atoms from a metallic electrode by use of ZnO layer. If a superlattice including the ZnO layer is employed as an optical guide layer or if the superlattice including the ZnO layer as an active layer, a long-life laser diode with a low operating voltage and a wide wavelength range can be obtained.

Abstract: A valence band quantum-well structure with a modulation doping for an optical-component implemented in Si technology. With this component, a high quantum efficiency and detection efficiency are accomplished. By way of spatial separation of the doped zone from the almost undoped SiGe quantum well, the Coulomb scattering and the recombination probability of the charge carriers drifting in the externally applied electrical field is greatly reduced at the doping material cores.

Abstract: A semiconductor device includes a semiconductor substrate; a semiconductor laminated structure including a first barrier layer, a conduction layer including a natural superlattice, and a second barrier layer, disposed on the semiconductor substrate. The first barrier layer, the conduction layer, and the second barrier layer produce heterojunctions that confine charge carriers within the conduction layer. The first barrier layer has steps at the surface contacting the conduction layer, the steps including, alternatingly arranged, a first crystal plane having a first orientation and a second crystal plane having a second orientation. The conduction layer includes first portions where the natural superlattice is ordered and second portions where the natural superlattice is disordered, the first and second portions being disposed on the first and second crystal planes, respectively. The degree of order in the conduction layer is higher in the first portions than in the second portions.

Abstract: A field effect transistor having a substrate supporting an active layer comprising a Group III-V material. The active layer has a dopant concentration with a source electrode and a drain electrode disposed over and with a gate electrode disposed between the source and drain electrodes in Schottky barrier contact to the active layer. A surface layer portion of the active layer has a negatively charged surface potential disposed between the drain and gate electrodes comprised of said Group III-V material and oxygen. The surface layer portion has a thickness in the range of 25 .ANG. to 35 .ANG.. A layer of passivation material is disposed at least on the surface layer portion of the active layer.

Abstract: A low-cost Si-based construction for optical and electronic bulk-heterostructure devices and multiple-quantum-well devices in which the active layers of the device are SiC or AlGaN or InGaN or InAlN. Material quality is high, and the MQW devices such as blue light lasers or LEDs have stable pseudomorphic layers with low defect densities. The low-cost large-area 3C SiC substrate is created by converting 100% of a 100-500 angstrom (.ANG.) layer of Si in a silicon-on-insulator wafer to 3C SiC with propane at 1300 degrees C. The SiO2 layer provides strain-free support for the "perfect" 3C SiC crystal layer. Direct-gap wurtzite nitride heterostructures, bulk or pseudomorphic MQW, are grown upon an (0001) 6H SiC epilayer on the (111) 3C SIC substrate, or directly upon the (111) 3C SiC substrate. For zincblende heterostructures, a (100) 3C SiC substrate is used.

Abstract: A heterojunction field effect transistor having an InP substrate, comprising a buffer layer formed between an active layer where a carrier travels and said InP substrate, wherein said buffer layer has at least two cycles of superlattices, each of said superlattices being formed of at least one semiconductor selected from the group consisting of Al.sub.x In.sub.1-x P (0.1.ltoreq.x.ltoreq.1), Ga.sub.x In.sub.1-x P (0.ltoreq.x.ltoreq.1), Al.sub.x Ga.sub.1-x As (0.ltoreq.x.ltoreq.1), and Al.sub.x In.sub.1-x As (0.5.ltoreq.x.ltoreq.1), and at least one semiconductor selected from the group consisting of InP and In.sub.0.52 Al.sub.0.48 As.

Abstract: An indium phosphide photovoltaic cell is provided where one or more quantum wells are introduced between the conventional p-conductivity and n-conductivity indium phosphide layer. The approach allows the cell to convert the light over a wider range of wavelengths than a conventional single junction cell and in particular convert efficiently transparency losses of the indium phosphide conventional cell. The approach hence may be used to increase the cell current output.A method of fabrication of photovoltaic devices is provided where ternary InAsP and InGaAs alloys are used as well material in the quantum well region and results in an increase of the cell current output.

Abstract: Modulated-structure polycrystalline or heteroepitaxial multilayers of PZT/PT ferroelectric thin films are deposited on a substrate, preferably by laser ablation. The laser ablation of the PZT/PT layers onto a prepared substrate occurs while maintaining the substrate at a temperature between 380.degree. C. to about 650.degree. C. The target source for the PZT/PT laser ablated film may be either bulk PZT and PT ceramics or powders or individual metal oxides or metal pellets. The ferroelectric thin film device may be used for a random access memory.

Abstract: Described is a semiconductor photo detector comprising, between a lower electrode and an upper electrode, an optical absorption layer which generates photo carriers, receiving light and an amplification layer which amplifies the photo carriers so generated. In the semiconductor photo detector, the amplification layer is formed of a well layer which causes an avalanche phenomenon and a barrier layer which has a band gap larger than that of the optical absorption layer. The well layer is formed of a crystal substance, by which at the interface with the barrier layer, the energy value of the conduction band of the photo carriers in the well layer is lower than that in the barrier layer and at the same time, the difference in the energy value of the conduction band between the well layer and the barrier layer is larger than the band gap between the valence band and the conduction band of the well layer.

Abstract: An optical semiconductor device provided with a strained quantum well layer uses a ternary mixed-crystal compound semiconductor substrate on which a strained quantum well layer sandwiched by barrier layers is formed.

Abstract: A semiconductor device having a quantum well structure, the quantum well structure having: a first quantum well layer for forming a quantum well for electrons, the first quantum well layer having a first band structure; a second quantum well layer for forming a quantum well for holes, the second quantum well layer having a second band structure different from the first band structure; and an intermediate layer interposed between the first and second quantum well layers having a third band structure different from the first and second band structures, wherein the first quantum well layer forms a barrier to holes, and the second quantum well layer forms a barrier to electrons. Semiconductor devices having quantum well structures different from conventional type I and II quantum well structures are provided.

Abstract: The disclosed novel doping method makes it possible to tailor the effective activation energy of a dopant species in semiconductor material. The method involves formation of very thin layers of .delta.-doped second semiconductor material in first semiconductor material, with the second material chosen to have a bandgap energy that differs from that of the first material. Exemplarily, in a Be-doped GaAs/AlGaAs structure according to the invention the effective activation energy of the dopant was measured to be about 4 meV, and in conventionally Be-doped GaAs it was measured to be about 19 meV. The invention can be advantageously used to dope III-V and II-VI semiconductors. In some cases it may make possible effective doping of a semiconductor for which prior art techniques are not satisfactory.

Abstract: The subject invention involves the p-type doping of Al.sub.x Ga.sub.1-x N thin films with a III-nitride composition and specifically a {Al.sub.x Ga.sub.1-x N/GaN} short-period superlattice structure of less than 5000 .ANG. thickness in total in which both the barriers and the wells are p-type doped with Mg.

Abstract: A semiconductor device includes a III-V compound semiconductor layer including two or more Group III elements and containing dopant impurities, including a spontaneous superlattice, and having a stripe shape with two ends, and electrodes disposed on the ends of the stripe shaped semiconductor layer to form a resistor element. Because of the spontaneous superlattice, electrons are one-dimensionally confined within the III-V compound semiconductor layer, i.e., the electrons flow easier in the direction perpendicular to the periodic direction of the spontaneous superlattice than in the direction parallel to it, resulting in anisotropic of electrical resistivity. Therefore, the orientation of the resistor element with respect to the periodic direction of the spontaneous superlattice becomes another factor in determining the resistance of the resistor element.

Abstract: The present invention relates to a semiconductor emission device with fast wavelength modulation and constituted by three sections, namely two lateral sections, each having an active layer and a DFB network and which produce an optical gain, connected across a central electroabsorbant section, to which is applied a reverse voltage making it possible to quasi-instantaneously modify the absorption rate in said section.

Abstract: In a wide band cap semiconductor, a GaP.sub.x N.sub.1-x (0.1.ltoreq.x.ltoreq.0.9) layer is inserted between a layer comprising AlGaInN and an electrode, The potential barrier between the electrode and the surface layer can be reduced. Contact resistance can be decreased, and ohmic contact can be easily taken up.

Abstract: A gain region for an interban quantum well laser incudes (a) an emitter ron of semiconductor material having at least one conduction subband and at least one valence subband, these subbands being spaced apart by an energy band-gap; (b) a collector region of semiconductor material having at least one conduction subband and at least one valence subband, these subbands spaced apart by an energy band-gap; (c) a type-I or type-II active region; and (d) a blocking quantum well region of semiconductor material between the active region and the collector region, for keeping electrons in the active region from tunnelling or scattering into the collector region, but allowing electrons in the highest valence subband in the active region to pass into the collector region.

Abstract: A photodetection semiconductor device is constructed in such a manner that a photodiode light absorbing layer includes an Si/SiGe super-lattice layer (6), which forms a layer in parallel with the surface of a silicon substrate (1), and upper and lower P type low Ge concentration SiGe epitaxial layers (5) and (7), which sandwich the Si/SiGe super-lattice layer between them and contain Ge lower than a Ge content in the Si/SiGe super-lattice layer, a highly dense P+ type Si contact layer (8) is directly formed on the upper SiGe epitaxial layer (7) and a highly dense N+ type epitaxial layer (2) is formed immediately below the lower SiGe epitaxial layer (5). Preferably, Ge concentration in each of the upper and lower SiGe epitaxial layers (5) and (7) is set to be at least 1% or higher.

Abstract: A resonant tunneling diode (400) made of a silicon quantum well (406) with silicon oxide tunneling barriers (404, 408). The tunneling barriers have openings (430) of size smaller than the electron wave packet spread to insure crystal alignment through the diode without affecting the tunneling barrier height.

Abstract: A gallium nitride type compound semiconductor light emitting element, such as a semiconductor laser, a light emitting diode is constructed by forming an In.sub.0.06 Ga.sub.0.94 N buffer layer, an n-type In.sub.0.06 Ga.sub.0.94 N clad layer, an n-type In.sub.0.06 Al.sub.0.15 Ga.sub.0.79 N clad layer, an undoped GaN active layer having layer thickness of 50 nm, a p-type In.sub.0.06 Al.sub.0.15 Ga.sub.0.79 N clad layer and a p-type In.sub.0.06 Ga.sub.0.94 N cap layer on a (0001) azimuth sapphire substrate. A p-side electrode is formed on the p-type In.sub.0.06 Ga.sub.0.94 N cap layer, and an n-side electrode is formed on the n-type In.sub.0.06 Ga.sub.0.94 N clad layer. In the construction set forth above, a greater thickness for the active layer is provided. Also, tensile strain is applied to the active layer. Light is taken out in parallel direction to the substrate. This threshold current of the semiconductor laser is lowered and light emitting efficiency of the light emitting diode is improved.

Abstract: A thermoelectric radiation detector having a substrate (1) and a film (2) of solid state material having thermal anisotropy and containing YBa.sub.2 Cu.sub.3 O.sub.7, formed on the surface of the substrate, and wherein said film has CuO.sub.2 planes (3) inclined with respect to the substrate plane, the improvement wherein at least a portion of the Y is replaced by another rare earth metal and/or at least a portion of the Ba and/or of the Cu is replaced by at least one other heavy metal at least in partial areas of the film and in a sufficient amount to increase the thermal anisotropy of the detector.

Abstract: Described is a semiconductor photo detector comprising, between two electrodes, at least one of said electrodes being a transparent electrode, an optical absorption layer which is composed of a non-single crystalline material, absorbs light and generates photo carriers and a carrier multiplication layer which is composed of a non-single crystalline material and multiplies the photo carriers generated by the optical absorption layer. The carrier multiplication layer is formed of a multilayer film obtained by stacking films each having plural layers which are composed of non-single crystalline Zn.sub.x Cd.sub.1-x M (0.ltoreq.x.ltoreq.1, M represents one selected from the group consisting of S, Se and Te) and are different in a composition ratio in accordance with a change in the value of x in said Zn.sub.x Cd.sub.1-x M, whereby a band discontinuity .DELTA.Ec of the conduction band can be made larger, an ionization rate of electrons can be heightened and the place where ionization occurs can be specified.

Abstract: A separate absorption thermal conduction band infrared photocathode fabricated with an engineered material system having energy band gaps specifically selected to provide an energy barrier that is selectively tuned to the momentum and energy of the photogenerated carriers. Such a material system produces an infrared detector having a substantially reduced dark current.

Abstract: Disclosed is an optical semiconductor device includes a multiquantum well structure comprising a well layer and a barrier layer, wherein: the well layer is made of InGaAsP, InGaAs or InGaP; the barrier layer is made of InGaAlAsP, InGaAlAs or InGaAlP; and optionally the well layer has the same In/Ga ratio as the barrier layer and the well layer is compressively strained. Also disclosed is a vapor-phase growth method of a multiquantum well structure comprises a well layer and a barrier layer or further comprises an intermediate layer between the well layer and the barrier layer, comprising the steps of: continuously supplying at a constant flow rate one or several V group gases and one or several first III group gases during the growth of the multiquantum well; forming the well and barrier layer by interrupting the supply of a second III group gas different from the first III group gas; and forming the intermediate layer by varying a flow rate of the second III group gas.

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: A logical operation circuit in which wiring as generally performed between transistors is made unnecessary to improve reliability, stability and integration degree of a logical circuit using a tunnel phenomenon, for example, a single-electron tunnel phenomenon, or a flight phenomenon of a particle group. Conducting materials are arranged in a two-dimensional plane or three-dimensional space in the logical circuit. When two conducting materials are arranged to be nearest each other, the two conducting materials are connected, for example, by a single-electron tunnel phenomenon. When two conducting materials are arranged to be not nearest, there is no connection between the conducting materials by the tunnel phenomenon. Propagation of electrons is controlled by changing the arrangement.