Abstract: A light control substance having a negative input-output characteristic is used to invert optical signals. The light control substance is an absorbing substance and has a multi-level energy structure such that ground state absorption occurs between a ground level and a level higher than the ground level and excited state absorption occurs between an excited level and a level higher than the excited level. At a specific wavelength, a variation .DELTA.Iout in the intensity of output light and a variation .DELTA.Iin in the intensity of input light satisfy the following equations:.DELTA.Iout=?1-.alpha..sub.1 (1+.alpha..sub.2 .gamma.)!.DELTA.Iin (1).alpha..sub.1 (1+.alpha..sub.2 .gamma.)>1 (2)where .alpha..sub.1 is an absorbance of the ground state absorption, .alpha..sub.2 is an absorbance of the excited state absorption, and .gamma. is a ratio of electrons relaxing from the level higher than the ground level to the exited level. As a result, the value of .DELTA.Iout/.DELTA.Iin becomes negative.

Abstract: By etching, a first groove and a second groove are formed in a silicon substrate. Surfaces of the side walls of these grooves have a surface orientation of (111). The first and second grooves sandwich a silicon thin plate therebetween, which is formed as a part of the silicon substrate. The silicon thin plate is sufficiently thin so as to act as a quantum well. Further, a pair of silicon oxide films acting as tunneling barriers are formed on the surfaces of the side walls of the silicon thin plate, thus forming a double barrier structure. In addition, a pair of polysilicon electrodes are formed and sandwich the double barrier structure. As a result, the structure of a resonance tunneling diode, which utilizes the resonance tunneling effect, is provided. Adding a third electrode to the above structure provides a resonance tunneling transistor.

Abstract: A method of increasing the saturation threshold of a super lattice optical absorber, and a resulting super lattice optical absorber, involves decreasing the electrical resistance of the substrate adjacent the super lattice structure based on a series resistance model.

Abstract: A semiconductor structure. The semiconductor structure comprises a plurality of semiconductor layers formed on a substrate including at least one layer of a III-V compound semiconductor alloy comprising aluminum (Al) and antimony (Sb), with at least a part of the AlSb-alloy layer being chemically converted by an oxidation process to form superposed electrically insulating and electrically conducting portions. The electrically insulating portion formed from the AlSb-alloy layer comprises an oxide of aluminum (e.g. Al.sub.2 O.sub.3), while the electrically conducting portion comprises Sb.

Abstract: A collective element of quantum boxes includes a plurality of the first quantum boxes (QD.sub.1) arranged within the first surface, between which conduction of electrons is allowed, a plurality of the second quantum boxes (QD.sub.2) arranged within the second surface corresponding to the plural first quantum boxes (QD.sub.1) between which conduction of electrons and holes is not substantially allowed, and a plurality of the third quantum boxes (QD.sub.3) arranged within the third surface corresponding to the plural second quantum boxes (QD.sub.2), between which conduction of holes is allowed.

Abstract: A method of fabricating a compositional semiconductor device comprising a antum well wire or quantum dot superlattice structure, in particular a device selected from the group comprising lasers, photodiodes, resonant tunneling transistors, resonant tunneling diodes, far infrared detectors, far infrared emitters, high electron mobility transistors, solar cells, optical modulators, optically bistable devices and bipolar transistors, by epitaxial growth of the superlattice structure on a semiconductor substrate, is characterised in that the epitaxial growth is effected on a {311}, {211}, {111} or {110} substrate, and that the devices preferably have length and width dimensions less than 500 .ANG. and especially less than 300 .ANG..

Abstract: A memory device and memory incorporating a plurality of the memory devices is described wherein each memory device has spaced apart source and drain regions, a channel, a barrier insulating layer, a nanocrystal or a plurality of nanocrystals, a control barrier layer, and a gate electrode. The nanocrystal which may be a quantum dot, stores one electron or hole or a discrete number of electrons or holes at room temperature to provide threshold voltage shifts in excess of the thermal voltage for each change in an electron or a hole stored. The invention utilizes Coulomb blockade in electrostatically coupling one or more stored electrons or holes to a channel while avoiding in-path Coulomb-blockade controlled conduction for sensing the stored charge.

Abstract: A quantum effect device includes a first layer having a plurality of charge confinement regions, a second layer opposing the first layer and separated from the first layer, the second layer having charges at a high concentration and consisting of a metal layer or a semiconductor layer, and a third layer consisting of an insulating layer or a semiconductor layer having a large band gap between the first layer and the second layer.

Abstract: III-V arsenide-nitride semiconductor crystals, methods for producing such crystals and devices employing such crystals. Group III elements are combined with group V elements, including at least nitrogen and arsenic, in concentrations chosen to lattice match commercially available crystalline substrates. Epitaxial growth of these III-V crystals results in direct bandgap materials, which can be used in applications such as light emitting diodes and lasers. Varying the concentrations of the elements in the III-V crystals varies the bandgaps, such that materials emitting light spanning the visible spectra, as well as mid-IR and near-UV emitters, can be created. Conversely, such material can be used to create devices that acquire light and convert the light to electricity, for applications such as full color photodetectors and solar energy collectors.

Abstract: A high performance thin film semiconductor device having a heterojunction such as a photoelectric conversion device is disclosed. In accordance with the present invention, the thin film semiconductor device comprises a thin semiconductor layer which forms a heterojunction with a non-single crystal silicon layer or non-single crystal silicon-germanium layer, wherein the valence band discontinuity at the heterointerface arising from the difference in optical energy bandgap is as small as 0.3 eV or less and wherein the thin semiconductor layer has an optical energy bandgap greater than 2.8 eV, so that hole transport performance may not be degraded. Such a thin semiconductor layer may be formed by using silane gas and methane gas with a flow rate ratio greater than 30 at a deposition rate less than 0.5 .ANG./sec.

Abstract: An electronic part is disclosed which is furnished with an artificial super lattice obtained by alternately superposing a substance of good conductivity formed of a compound between one element selected from among the elements belonging to the transition elements of Groups 3A to 6A and the rare earth elements and an element selected from among boron, carbon, nitrogen, phosphorus, selenium, and tellurium or a compound between oxygen and a transition metal element selected from among the elements of Group 7A and Group 8 and an insulating substance formed of a compound between a simple metal element selected from among the elements belonging to Group 1A, Group 2A, and Groups 1B to 4B and an element selected from among carbon, nitrogen, oxygen, phosphorus, sulfur, selenium, tellurium, and halogen elements in thicknesses fit for obtaining a quantum size effect.

Abstract: A semiconductor device includes a semi-insulating semiconductor substrate, a semiconductor layer structure including at least an undoped layer of a first semiconductor, an undoped spacer layer of a second semiconductor having an electron affinity smaller than that of the first semiconductor, and an n type electron supply layer of the second semiconductor successively laminated on the substrate, the undoped layer having a flat top surface and a flat rear surface on the flat top surface of the undoped spacer layer, having, at a top surface, a concavo-convex periodic structure, and a flat rear surface, the n-type electron supply layer of the second semiconductor having a flat top surface and a rear surface that buries concavities of the concavo-convex structure of the undoped spacer layer, and a plurality of periodically arranged Schottky electrodes on the flat top surface of the n type electron supply layer, arranged in a direction perpendicular to the concavo-convex periodic structure of the undoped spacer lay

Abstract: A semiconductor light-emitting device that enables to realize a satisfactory carrier confinement effect to be capable of stable operation at room temperature. This device includes a QW layer and p- and n-barrier layers placed at each side of the QW layer. The QW layer has an energy level E.sub.va at the top of the valence band and an energy level E.sub.ca at the bottom of the conduction band. The p-barrier layer has an energy level E.sub.vpb at the top of the valence band and an energy level E.sub.cpb at the bottom of the conduction band. The n-barrier layer has an energy level E.sub.vnb at the top of the valence band and an energy level E.sub.cnb at the bottom of the conduction band. The energy levels E.sub.va, E.sub.vpb and E.sub.vnb at the top of the valence band satisfy the relationship of E.sub.va >E.sub.vpb >E.sub.vnb. The energy levels E.sub.ca, E.sub.cpb and E.sub.cnb at the bottom of the conduction band satisfy the relationship of E.sub.va <E.sub.vnb <E.sub.vpb.

Abstract: A semiconductor light emitting device comprises a first cladding layer, an active layer and a second cladding layer which are stacked on a semiconductor substrate. At least a part of the first cladding layer and the second cladding layer has a superlattice structure comprising II-VI compound semiconductor. Another semiconductor light emitting device comprises a first cladding layer, a first guide layer, an active layer, a second guide layer and a second cladding layer which are stacked on semiconductor substrate. At least a part of the first cladding layer, the first guide layer, the second cladding layer and the second guide layer has a superlattice structure. Still another semiconductor light emitting device comprises a defect decomposing layer, a defect blocking layer, first cladding layer, an active layer, a second cladding layer which are stacked on a semiconductor substrate. The defect decomposing layer and the defect blocking layer comprise a superlattice structure.

Abstract: A quantum memory has memory cells, each of the memory cells includes three-stage quantum dots stacked in sequence. A memory cell array is constructed by two-dimensionally arranging the memory cells. The quantum dots are made of heterojunctions of compound semiconductors. Writing and reading to and from a memory cell are executed by bringing a needle electrode close to the memory cell to apply an external electric field while irradiating laser light to an area including the memory cell.

Abstract: A heterojunction tunnel diode with first and second barrier layers, the first barrier layer including aluminum antimonide arsenide. A quantum well formation is sandwiched between the first and second barrier layers, and includes first and second quantum well layers with a barrier layer sandwiched therebetween, the first quantum well layer being adjacent the first barrier layer. The first quantum well layer is gallium antimonide arsenide which produces a peak in hole accumulations therein. The second quantum well layer produces a peak in electron accumulations therein. A monolayer of gallium antimonide is sandwiched in the first quantum well layer at the peak in hole accumulations and a monolayer of indium arsenide is sandwiched in the second quantum well layer at the peak in electron accumulations.

Abstract: A semiconductor device is provided, including a semiconductor substrate of zinc blend structure, defined by a principal surface substantially coinciding to a {111}A-oriented crystal surface; an etch pit of the shape of a triangular pyramid, formed on the principal surface of the substrate, the etch pit being defined by side walls merging at an apex of said triangular pyramid, each two of the side walls merging at a valley of the triangular pyramid; and an active part formed on the etch pit; wherein the active part includes a quantum well layer having a first bandgap and provided along the side walls of the etch pit, and a pair of barrier layers having a second, larger bandgap and provided so as to sandwich the quantum well 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: The subject invention comprises a plurality of serially connected small volume photovoltaic devices. A single device includes a first layer of n.sup.+ doped InSb, a second layer of doped IDAs.sub.1-x Sb.sub.x and a third layer of p.sup.+ doped InSb. From 2-50 of these devices are grown by either a low-pressure MOCVD or MBE process to a maximum thickness of about 10 .mu.m. Alternatively, the first layer may be n.sup.+ doped In.sub.y Ga.sub.1-y, Sb the second layer p.sup.+ doped InAs.sub.1-x Sb.sub.x and the third layer In.sub.y Ga.sub.1-y Sb, repeated to a maximum thickness of 10 m.

Abstract: A light switching apparatus includes an optically non-linear etalon, a first optical part for applying a signal light of a linear polarization to the optically non-linear etalon, and a second optical part for applying a control light of a circular polarization or elliptical polarization to the optically non-linear etalon. The control light varies a refractive index of an optically non-linear substance of the optically non-linear etalon to thereby perform a switching operation on the signal light.

Abstract: A quantum well intersubband infrared (IR) photodetector has a spectral response tunable by an external voltage. The photodetector consists of multiple doped quantum wells with different well widths and barrier heights. The preferred embodiment is made by repeating the whole structure of the active region of a multiple quantum well intersubband IR photodetector. Differences between repeats or groups of well widths and barrier heights result in differences in the spectral IR response of the different repeats. The device resistance of a given group is designed to be very different from those for all the other groups. As a function of an applied voltage, the repeat with the highest resistance will be turned on to detect IR with the response peak at a wavelength .lambda..sub.1. Subsequently, the next highest resistance repeat will turn on when increasing voltage with its response peaked at .lambda..sub.2, and so on. Since .lambda..sub.1, .lambda..sub.

Abstract: The single electron transistor can be operated at room temperature. The distance between the electrodes 5, 5 can be adjusted by the length of the protein and/or the wideness of the lipid bilayer and the distance between the quantum dot 4 and one of the electrodes 5 can be adjusted in units of 1.5 .ANG. by means of .alpha.-helix confirmation of a G segment of the protein.

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 infrared emitting device and method. The infrared emitting device comprises a III-V compound semiconductor substrate upon which are grown a quantum-well active region having a plurality of quantum-well layers formed of a ternary alloy comprising InAsSb sandwiched between barrier layers formed of a ternary alloy having a smaller lattice constant and a larger energy bandgap than the quantum-well layers. The quantum-well layers are preferably compressively strained to increase the threshold energy for Auger recombination; and a method is provided for determining the preferred thickness for the quantum-well layers. Embodiments of the present invention are described having at least one cladding layer to increase the optical and carrier confinement in the active region, and to provide for waveguiding of the light generated within the active region.

Abstract: A semiconductor device having: an underlie having a semiconductor surface capable of growing thereon single crystal; and a first semiconductor layer, the first semiconductor layer including: a first region of group III-V compound semiconductor epitaxially grown on generally the whole area of the semiconductor surface; and second regions of group III-V compound semiconductor disposed and scattered in the first region, the second region having a different composition ratio of constituent elements from the first region, wherein lattice constants of the first and second regions in no strain state differ from a lattice constant of the semiconductor surface, and a difference between the lattice constant of the second region in no strain state and the lattice constant of the semiconductor surface is greater than a difference between the lattice constant of the first region in no strain state and the lattice constant of the semiconductor surface.

Abstract: A quantum well device has an active region adapted to pass a tunneling current of charge carriers and comprising layers of material forming alternating potential barriers and potential wells. The structure defines, in use, a first potential well at one end of the active region, said first potential well defining a first quasi-defined energy level, and to further define second and third quasi-defined energy levels. The relative heights and thicknesses of the potential barriers when the device is in use are structured so that the first quasi-defined energy level has a longer lifetime than the second and third quasi-defined energy levels and there is a degree of coupling between the three quasi-defined energy levels which is strongest between the second and third quasi-defined energy levels. The transmission coefficient through the active region shows a resonance peak at each of the energies of the three quasi-defined energy levels.

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, and the openings (430) have an irregular (nonperiodic) shape.

Abstract: The present invention provides an ohmic contact device which comprises: a first layer made of a first compound semiconductor having a first energy band gap; a superlattice in contact with the first layer, the superlattice having modulation-periods comprising alternating a first very thin layer made of the first compound semiconductor and a second very thin layer made of a second compound semiconductor having a second energy band gap being smaller than the first energy band gap, thicknesses of the first very thin layers being gradually reduced from an interface of the first layer to an opposite interface and thicknesses of the second very thin layers are gradually increased from the interface of the first layer to the opposite interface; a second layer made of the second compound semiconductor in contact with the superlattice; and a metal contact in contact with the second layer.

Abstract: The present invention relates to quantum well semiconductor light emitting devices such as lasers that utilize resonant tunneling for carrier injection and spatially-diagonal transitions between an energy state in the conduction band of one quantum well and an energy state in the valence band of the adjacent quantum well for light emission, resulting in much improvement in both radiative efficiency and carrier injection efficiency. An elementary structure of the invented devices comprises two spatially coupled quantum wells residing in conduction and valence bands respectively wherein the valence band-edge in one quantum well is higher than the conduction band-edge of the other quantum well. Each quantum well contains at least one energy state formed by the quantum size effect.

Abstract: A multilayer structure having an oxygen or dopant diffusion barrier fabricated of an electrically conductive, thermally stable material of refractory metal-silicon-nitrogen which is resistant to oxidation, prevents out-diffusion of dopants from silicon and has a wide process window wherein the refractory metal is selected from Ta, W, Nb, V, Ti, Zr, Hf, Cr and Mo.

Abstract: Disclosed is a semiconductor optical integrated device and method of fabricating the device, the device having a plurality of quantum well structures, formed on a single substrate, acting as optical waveguides, the plurality of quantum well structures respectively having different lattice mismatches with the substrate and/or different strains (e.g., respectively compressive strain and tensile strain). The method includes selectively depositing the quantum well structures by, e.g., organometallic vapor phase epitaxy on growth regions of the substrate, the growth regions being defined by insulating layer patterning masks, with a width of the growth regions and/or a width of the patterning mask being different for the different quantum well structures.

Abstract: An optical controlled resonant tunneling oscillator utilizing an oscillation variation characteristic of a resonant tunneling oscillator in accordance with a negative differential resistance, a series resistance and a static capacitance varied with an intensity of light when the light is incident on a resonant tunneling device having a double barrier quantum well structure and a method for fabricating the same are disclosed. The oscillator can modulate the frequency 2 or 3 levels in response to an intensity of an incident light as compared with the method of a conventioal photoelectric system that modulates the frequency in response to ON/OFF of an electric signal, thereby simplifying the system. The oscillator controls the resonant tunneling at the high speed by light, thereby enabling processing a signal of tens to hundreds GHz.

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: An improved multiquantum well superlattice photodetector (10) for detecting long wavelength infrared radiation. Electron transport in a first excited energy state is enhanced in barrier layers (20) of the superlattice (16) by lowering the potential energy barriers of the barrier layers (20) to a predetermined level below the first excited energy state. The tunneling component of the dark current in a multiquantum well photodetector (10) may be substantially eliminated by placing a blocking layer (22) at one end of the superlattice (16). The thickness of the blocking layer (22) is also substantially greater than that of the barrier layers (20) of the superlattice (16) to prevent charge carriers which tunnel through the superlattice (16) from reaching the collector contact. The blocking layer (22) also has a potential energy barrier having a height at a level higher than that of the barrier layers (20) of the superlattice (16).

Abstract: An opto-semiconductor device is disclosed which is provided with a quantum well structure comprising a first and a second barrier layer and a well layer sandwiched by the barrier layers. The barrier layers are provided in at least part thereof with a strain layer enabled to generate an internal electric field by a piezoelectric effect. The barrier layers are adapted to sandwich the well layers.

Abstract: A semiconductor light-emitting device employs a quantum well having a fundamental wavelength in the absence of an external electric field; a microcavity with two reflectors, having a resonance wavelength which closely corresponds to the fundamental wavelength of the quantum well; and electrodes for applying an electric field across the microcavity to change the wavelength of the quantum well and thereby control the radiance of the microcavity.

Abstract: A substrate upon which infrared elements are formed has a crystalline base layer, preferably comprised of silicon; a first strain superlattice layer formed upon the base layer; and a first matched superlattice layer formed upon the strain superlattice layer. The strain superlattice layer and the matched superlattice layer mitigate defect propagation from the base layer to the infrared detector elements. Optionally, a plurality of additional or second strain and matched superlattice layers are formed in an alternating layer configuration upon the first matched superlattice layer so as to achieve enhanced defect filtering.

Abstract: An organic semiconductor including an organic semiconductor layer, which layer is formed by epitaxially depositing molecules of a compound selected from phthalocyanines to form a super-thin film configuration including one-dimensional columns of stacked molecules in the form of quantum wires separated respectively from each other.

Abstract: Layers each consisting of one of two types of compound semiconductors A and B different from each other in a lattice constant a and an energy band gap Eg (a(A)>a(B), Eg(A)<Eg(B)) are stacked in a [111] direction on a compound semiconductor substrate whose major surface is a surface. When each layer consisting of the compound semiconductor A serves as a well layer and each layer consisting of the compound semiconductor B serves as a barrier layer, the barrier layer is formed to have a thickness larger than the critical film thickness of strain relaxation in that barrier layer and is thereby so strained as to be pulled in a direction parallel to a crystal growth surface. The well layer is so strained as to be compressed in the direction parallel to the crystal growth surface owing to partial relaxation of a strain confined in the barrier layer. This can achieve as large an optical bistable effect as possible while maintaining the light blue-shift absorption characteristic.

Abstract: In a light emitting device made of a group II-VI semiconductor of ZnCdSSe or MgZnCdSSe, to facilitate the movement of electrons or holes from a GaAs substrate to a group II-VI semiconductor film and to flow the current at a low voltage, a ZnSe--AlGaAs super lattice layer is formed between the group II-VI semiconductor film and the GaAs substrate so that the energy band from the substrate to the group II-VI semiconductor film rises in steps or gradually. In an device where an N-type semiconductor layer of the group II-VI semiconductor film is arranged on the side of the substrate, a P-type semiconductor film which raises the energy band from the electrode to the P-type semiconductor layer in steps is formed between the electrode and the P-type semiconductor layer which is the top layer of the group II-VI semiconductor film.

Abstract: An optical operator designed to be subjected to write radiation for processing read radiation that it receives, the operator comprising an electro-optical material (Q2), first and second materials (Q1, Q3) distributed on either side of the electro-optical material (Q2), said first and second materials (Q1, Q3) being collection quantum wells. Quantum barrier forming materials (6, 8) are interposed between said two materials (Q1, Q3) and the electro-optical material (Q2), with one of the quantum barrier forming materials (6) constituting a filter such that charges of a certain sign photoexcited by the write radiation in a material (4, Q1) on one side of said filter pass through it in the absence of an external electric field to relax in the collection quantum well (Q3) situated on the other side of the filter (6), while charges of opposite sign are blocked by the filter (6) in the other collection well (Q1).

Abstract: A waveguide type electro-absorptive optical modulator that resists damage to its input facet and methods for minimizing or eliminating optical and electrical damage to the input facet of waveguide type electro-absorptive modulator by fabrication of an electrically isolated region in the modulator's waveguide proximate the input facet by forming an ion implantation region in at least one waveguide confinement rib proximate the input facet, a signal contact end on the at least one rib that is recessed from the plane of the input facet, or both.

Abstract: A quantum box array comprising a plurality of quantum boxes is made by providing a plurality of box-shaped quantum well portions on a first barrier layer and a second barrier layer covering the quantum well portions. The quantum box array is designed so that interaction energy between electrons or holes is amply larger than transfer energy between the quantum boxes. A control electrode is provided on the second barrier layer to vary the number of electrons or holes in the quantum box array by changing the potential of the control electrode. In spite of using a relatively small number of electrons or holes, the quantum device can suppress fluctuation in density of electrons or holes, can have three or more states, and reduces the power consumption.

Abstract: Quantum well infrared photodetectors (QWIPs) according to the invention have a surface that provides pseudo-random reflection of the radiation that is incident thereon, resulting in an increase in the effective number of passes of the radiation through the quantum well region, and hence in increased responsivity of the QWIPs, as compared to corresponding prior art grating QWIPs. A convenient approach to forming the pseudo-random reflecting surface is disclosed.

Abstract: An electromagnetic wave detector formed of semiconductor materials includes at least one quantum well in which there is provided a fine layer of a material with a gap width that is smaller than that of the quantum well layer. For example, in the case of a GaAlAs/GaAs/GaAlAs, there is provision for a fine layer of InAs. In this way, the difference of energy levels between the two permitted levels is increased and detection of short wavelengths may be accomplished.

Abstract: A solar cell formed from a semiconductor having a relative wide band-gap E.sub.b- characterized by a multi-quantum well system incorporated in the depletion region of the cell in which the quantum wells comprise regions of semiconductor with a smaller band gap separated by small amounts of the wider band-gap semiconductor (E.sub.b) so that the effective band-gap for absorption (E.sub.a) is less than E.sub.b.

Abstract: A semiconductor crystalline laminate structure wherein between a first semiconductor layer consisting of a first alloyed semiconductor and a second semiconductor layer which has an energy gap wider than that of the first alloyed semiconductor and a lattice constant smaller than that of the first alloyed semiconductor and consists of one semiconductor selected from a group of single-element semiconductor, compound semiconductor, and alloyed semiconductor which contain no semiconductor having a largest lattice constant among the semiconductor constituting the first alloyed semiconductor, a third semiconductor layer which consists of a second alloyed semiconductor having an energy gap wider than that of the first alloyed semiconductor and contains the semiconductor having a largest lattice constant among the semiconductors constituting the first alloyed semiconductor is formed in contact with these layers, a forming method for the semiconductor crystalline laminate structure, and a semiconductor device using the

Abstract: A current-controlled resonant tunneling diode (RTD) having an InAs quantum well, AlGaSb barriers and InAs cladding layers is disclosed. The RTD of this invention displays an S-shaped negative differential resistance in its I-V relationship. As a result, the RTD displays the bistability necessary to greatly enhance the speed of operation of many key electronic components by eliminating the need for large load resistances in the circuit design.

Abstract: A Type II heterojunction formed of semiconductor material which normally forms a Type I heterojunction. The Type II heterojunction is created by using a carefully chosen stack of epitaxial semiconductor materials with modifications to the band structure through quantum mechanical confinement effects. This virtual type II heterojunction is incorporated adjacent to the active region in a single-quantum-well, ridge-waveguide laser structure. An anomalous "Negative-T.sub.o " region is observed in which threshold current decreases with increasing temperature. A reduction in the temperature sensitivity of the threshold current of the laser structure results.

Abstract: Compatibility of high sensitivity with low remaining images, and low crosstalk can be achieved by a laminated solid-state image pickup device, which includes accumulating portions for accumulating electric signals, reading units for reading the electric signals, connecting members formed in contact with the accumulating portions, and a photoconductive film, and by a method for manufacturing the device. The photoconductive film is made of a non-crystalline semiconductor, and is configured by laminating a carrier multiplication layer, a light absorbing layer, a charge injection inhibiting layer of a second conduction type. Each of the connecting members is made of a semiconductor layer of a first conduction type, intrinsic or having a low impurity density, surrounded by a semiconductor layer of the second conduction type or a conductive material.