Abstract: A superlattice structure includes a plurality of quantum-dot nanowires extending in a substantially vertical direction from a plane region. The quantum-dot nanowires have a structure of barrier layers and quantum-dot layers alternately stacked on the plane region, and the quantum-dot nanowires are substantially the same in diameter in a stacking direction and substantially uniformly arranged at an area density of 4 nanowires/?m2 or more.

Abstract: A method for manufacturing a semiconductor light emitting device includes forming a lower cladding layer over a GaAs substrate; forming a quantum dot active layer over the lower cladding layer; forming a first semiconductor layer over the quantum dot active layer; forming a diffraction grating by etching the first semiconductor layer; forming a second semiconductor layer burying the diffraction grating; and forming an upper cladding layer having a conductive type different from that of the lower cladding layer over the second semiconductor layer, wherein the processes after forming the quantum dot active layer are performed at a temperature not thermally deteriorating or degrading quantum dots included in the quantum dot active layer.

Abstract: A semiconductor light emitting device includes a lower cladding layer, an active layer, and an AlGaAs upper cladding layer mounted on a GaAs substrate. The semiconductor light emitting device has a ridge structure including the AlGaAs upper cladding layer. The semiconductor light emitting device further includes an InGaAs etching stop layer provided in contact with the lower side of the AlGaAs upper cladding layer. The InGaAs etching stop layer has a band gap greater than that of the active layer.

Abstract: A semiconductor light emitting device includes a lower cladding layer, an active layer, and an AlGaAs upper cladding layer mounted on a GaAs substrate. The semiconductor light emitting device has a ridge structure including the AlGaAs upper cladding layer. The semiconductor light emitting device further includes an InGaAs etching stop layer provided in contact with the lower side of the AlGaAs upper cladding layer. The InGaAs etching stop layer has a band gap greater than that of the active layer.

Abstract: An organic thin-film transistor of the present invention has a gate electrode, a gate insulating film, a source electrode, a drain electrode, and an organic semiconductor layer provided above a substrate, and further has a thiol compound layer composed of a benzenethiol compound and provided on a surface of the source electrode and a thiol compound layer composed of a benzenethiol compound and provided on a surface of the drain electrode. This makes it possible to provide an organic thin-film transistor whose threshold voltage can be selectively controlled without greatly affecting a current characteristic other than the threshold voltage.

Abstract: An active layer having a p-type quantum dot structure is disposed over a lower cladding layer made of semiconductor material of a first conductivity type. An upper cladding layer is disposed over the active layer. The upper cladding layer is made of semiconductor material, and includes a ridge portion and a cover portion. The ridge portion extends in one direction, and the cover portion covers the surface on both sides of the ridge portion. A capacitance reducing region is disposed on both sides of the ridge portion and reaching at least the lower surface of the cover portion. The capacitance reducing region has the first conductivity type or a higher resistivity than that of the ridge portion, and the ridge portion has a second conductivity type. If the lower cladding layer is an n-type, the capacitance reducing region reaches at least the upper surface of the lower cladding layer.

Abstract: A solar cell of the present invention comprises a p-type semiconductor layer, an n-type semiconductor layer and a superlattice semiconductor layer sandwiched between the p-type semiconductor layer and the n-type semiconductor layer, wherein the superlattice semiconductor layer has a superlattice structure in which barrier layers and quantum layers are stacked alternately and repeatedly, and has two or more intermediate energy levels where electrons optically excited from a valence band of the quantum layers or the barrier layers stay for a constant time, the intermediate energy levels being located between a top of the valence band of the barrier layers and a bottom of a conduction band of the barrier layers, and can achieve a high incident photon-to-current conversion efficiency.

Abstract: The method of manufacturing the semiconductor device comprises the step of forming quantum dots 16 on a base layer 10 by self-assembled growth; the step of irradiating Sb or GaSb to the surface of the base layer 10 before or in the step of forming quantum dots 16; the step of etching the surfaces of the quantum dots 16 with an As raw material gas to thereby remove an InSb layer 18 containing Sb deposited on the surfaces of the quantum dots 16; and growing a capping layer 22 on the quantum dots 16 with the InSb layer 18 removed.

Abstract: A method of identifying target analytes in a sample, particularly a biological sample, comprising the steps of putting a plurality of target analytes, bound to a common luminescent marker, in contact with a plurality of molecular probes immobilized on a support, each of said molecular probes being capable of complementary binding to a respective target analyte, if said target analyte is present in the sample, providing to said support an excitation radiation and detecting an emission radiation coming from said support as a result of at least one complementary binding event, characterized by the fact that: said support comprises a plurality of photonic crystal resonators, at least two of said resonators being characterized by different resonance wavelengths; each of said molecular probes being fixed to a respective resonator; and by the fact that the identification of at least one target analyte is carried out through the analysis of the total emission spectrum coming from said plurality of photonic crystal

Abstract: The method of manufacturing the semiconductor device comprises the step of forming quantum dots 16 on a base layer 10 by self-assembled growth; the step of irradiating Sb or GaSb to the surface of the base layer 10 before or in the step of forming quantum dots 16; the step of etching the surfaces of the quantum dots 16 with an As raw material gas to thereby remove an InSb layer 18 containing Sb deposited on the surfaces of the quantum dots 16; and growing a capping layer 22 on the quantum dots 16 with the InSb layer 18 removed.

Abstract: The method of manufacturing the semiconductor device comprises the step of forming quantum dots 16 on a base layer 10 by self-assembled growth; the step of irradiating Sb or GaSb to the surface of the base layer 10 before or in the step of forming quantum dots 16; the step of etching the surfaces of the quantum dots 16 with an As raw material gas to thereby remove an InSb layer 18 containing Sb deposited on the surfaces of the quantum dots 16; and growing a capping layer 22 on the quantum dots 16 with the InSb layer 18 removed.

Abstract: An active layer (18) is formed over a semiconductor substrate having a pair of facets (15A, 15B) mutually facing opposite directions. An upper cladding layer (19) is formed on the active layer, having a refractive index lower than that of the active layer. A diffraction grating (25) is disposed in the upper cladding layer on both sides of a distributed feedback region in a waveguide region (22), the waveguide region extending from one facet to the other of the semiconductor substrate. End regions (22B) are defined at both ends of the waveguide region and the distributed feedback region (22A) is disposed between the end regions. Low refractive index regions (26) are disposed in the upper cladding layer on both sides of each of the end regions of the waveguide region, the low refractive index regions having a refractive index lower than that of the upper cladding layer.

Abstract: An active layer (18) is formed over a semiconductor substrate having a pair of facets (15A, 15B) mutually facing opposite directions. An upper cladding layer (19) is formed on the active layer, having a refractive index lower than that of the active layer. A diffraction grating (25) is disposed in the upper cladding layer on both sides of a distributed feedback region in a waveguide region (22), the waveguide region extending from one facet to the other of the semiconductor substrate. End regions (22B) are defined at both ends of the waveguide region and the distributed feedback region (22A) is disposed between the end regions. Low refractive index regions (26) are disposed in the upper cladding layer on both sides of each of the end regions of the waveguide region, the low refractive index regions having a refractive index lower than that of the upper cladding layer.

Abstract: A quantum dot semiconductor device includes an active layer having a plurality of quantum dot layers each including a composite quantum dot formed by stacking a plurality of quantum dots and a side barrier layer formed in contact with a side face of the composite quantum dot. The stack number of the quantum dots and the magnitude of strain of the side barrier layer from which each of the quantum dot layers is formed are set so that a gain spectrum of the active layer has a flat gain bandwidth corresponding to a shift amount of the gain spectrum within a desired operation temperature range.

Abstract: A single-photon generator includes a single-photon generating device generating a single-photon pulse having a wavelength on the shorter wavelength side than a communication wavelength band, and a single-photon wavelength conversion device performing wavelength conversion of the single-photon pulse into a single-photon pulse of the communication wavelength band, using pump pulse light for single-photon wavelength conversion.

Abstract: An organic thin-film transistor of the present invention has a gate electrode, a gate insulating film, a source electrode, a drain electrode, and an organic semiconductor layer provided above a substrate, and further has a thiol compound layer composed of a benzenethiol compound and provided on a surface of the source electrode and a thiol compound layer composed of a benzenethiol compound and provided on a surface of the drain electrode. This makes it possible to provide an organic thin-film transistor whose threshold voltage can be selectively controlled without greatly affecting a current characteristic other than the threshold voltage.

Abstract: An optical semiconductor device includes: a waveguide structure including layers grown over a semiconductor substrate, having a width defined by sidewalls formed by etching the layers, and including a wide, a narrow, and an intermediate width portion, formed along a propagation direction; and a diffraction grating formed on the sidewalls of at least one of the wide and narrow width portions of the waveguide structure, the diffraction grating having vertical grooves periodically disposed along the propagation direction and defining a wavelength of propagation light, wherein the narrow width portion is formed in such a manner that a loss of 50% or more is given to a higher order transverse mode. An optical semiconductor device having a vertical diffraction grating is provided which can suppress generation of a higher order transverse mode and an increase in a device resistance.

Abstract: A single-photon generating device is configured to have a solid substrate including abase portion, and a pillar portion which is formed on the surface side of the base portion with a localized level existent in the vicinity of the tip of the base portion. The above pillar portion is formed to have a larger cross section on the base portion side than the cross section on the tip side, so that the light generated from the localized level is reflected on the surface, propagated inside the pillar portion, and output from the back face side of the base portion.

Abstract: A method of identifying target analytes in a sample, particularly a biological sample, comprising the steps of putting a plurality of target analytes, bound to a common luminescent marker, in contact with a plurality of molecular probes immobilized on a support, each of said molecular probes being capable of complementary binding to a respective target analyte, if said target analyte is present in the sample, providing to said support an excitation radiation and detecting an emission radiation coming from said support as a result of at least one complementary binding event, characterized by the fact that: said support comprises a plurality of photonic crystal resonators, at least two of said resonators being characterized by different resonance wavelengths; each of said molecular probes being fixed to a respective resonator; and by the fact that the identification of at least one target analyte is carried out through the analysis of the total emission spectrum coming from said plurality of photonic crystal

Abstract: The light emitting device comprises a substrate 10 of a p-type semiconductor; an active layer 20 formed of a plurality of quantum dot layers 18 stacked, the quantum dot layers 18 having three-dimensional grown islands self-formed by S-K mode, respectively; and an n-type semiconductor layer 22 formed over the active layer. Because of the p-type semiconductor, over which the active layer 20 is formed on, and the n-type semiconductor, which is formed over the active layer 20, lower layer regions of the active layer 20, where good quantum dots 19 are formed are nearer to regions of the active layer 20, which are nearer to the p-type semiconductor. Accordingly, the radiation recombination between the holes and electrons takes place mainly in the regions where those of the quantum dots, which are of good quality. Thus, even when a number of the quantum dot layers 18 are stacked, good device characteristics can be obtained.