A nitride semiconductor light-emitting device has an active layer of a single-quantum well structure or multi-quantum well made of a nitride semiconductor containing indium and gallium. A first p-type clad layer made of a p-type nitride semiconductor containing aluminum and gallium is provided in contact with one surface of the active layer. A second p-type clad layer made of a p-type nitride semiconductor containing aluminum and gallium is provided on the first p-type clad layer. The second p-type clad layer has a larger band gap than that of the first p-type clad layer. An n-type semiconductor layer is provided in contact with the other surface of the active layer.

Nitride semiconductor light emitting device

A nitride semiconductor element exhibiting low leakage current and high ESD tolerance includes an active layer of nitride semiconductor that is interposed between a p-sided layer and an n-sided layer, which respectively consist of a plurality of nitride semiconductor layers, the p-side layer including a p-type contact layer as a layer for forming p-ohmic electrodes, the p-type contact layer being formed by laminating p-type nitride semiconductor layers and n-type nitride semiconductor layers in an alternate manner.

Nitride semiconductor element

Strained-semiconductor-on-insulator device structures

The present disclosure relates to a semiconductor light emitting device, comprising: a plurality of semiconductor layers, including a first semiconductor layer having a first conductivity, a second semiconductor layer having a second conductivity different from the first conductivity, and an active layer interposed between the first semiconductor layer and the second semiconductor layer, generating light via electron-hole recombination; a first electrode, supplying either electrons or holes to the plurality of semiconductor layers; a second electrode, supplying, to the plurality of semiconductor layers, electrons if the holes are supplied by the first electrode, or holes if the electrons are supplied by the first electrode; a non-conductive distributed bragg reflector coupled to the plurality of semiconductor layers, reflecting the light from the active layer; and a first light-transmitting film coupled to the distributed bragg reflector from a side opposite to the plurality of semiconductor layers with respect to the non-conductive distributed bragg reflector, with the first light-transmitting film having a refractive index lower than an effective refractive index of the distributed bragg reflector.

Semiconductor Light Emitting Device

The author summarizes processing of bulk YBa2Cu3Ox superconductors with an emphasis placed on the relationship between microstructure and critical currents. Sintering is commonly used in ceramic processing but has been unsuccessful in producing high-Jc materials, primarily due to the weak links at grain boundaries. Melt processes have been found to be effective in increasing Jc values through a combination of grain alignment and the introduction of pinning centres. Some possible applications of melt processed superconductors in bulk form are also introduced in this review. Although many attempts have been made to fabricate long conductors, Jc values are still very small for long conductors, while the length is limited for high-Jc materials.

Processing of bulk YBaCuO

PROBLEM TO BE SOLVED: To provide a surface-emitting laser element that can achieve high speed modulation, high reliability, and a good transmission characteristic at the same time.SOLUTION: A surface-emitting laser element comprises: a lower multilayer film reflector and an upper multilayer film reflector constructed by a periodic structure of a high refractive index layer and a low refractive index layer, and forming an optical resonator: an active layer formed between the lower multilayer film reflector and the upper multilayer film reflector; and a plurality of current constriction layers formed between the upper multilayer film reflector and the active layer, or within the upper multilayer film reflector, and including a current injection part and a selective oxidation layer formed on the outer periphery of the current injection part by selective oxidation thermal processing. The plurality of current constriction layers each are equal to or less than 60 nm in layer thickness, are formed at places nearly corresponding to nodes of the standing wave of light formed by the optical resonator.

Surface-emitting laser element

The study of next-generation high-energy accelerators based on 16 T dipoles has emphasized the need for higher performance, cost-effective Nb
 3
Sn superconducting wires. A Conductor Development Program aiming to reach a non-copper critical current density (J
 c
) of 1500 A/mm
 2
 at 16 T and 4.2 K has been launched by CERN, with the involvement of industry and laboratories worldwide. In this paper, the targets and strategy of the program are presented, with an overview of the wire layouts and development activities being pursued by each partner, and the latest characterization results are reported. Three of the four participating manufacturers have successfully reached the first-stage J
 c
 milestone, but a significant advance is still needed to achieve the final target. The next steps are briefly discussed, as the program focuses increasingly on novel alloys and methods to maximize J
 c
.

http://cds.cern.ch/record/2651027/files/CERN-ACC-2019-0001.pdf

The CERN FCC Conductor Development Program: A Worldwide Effort for the Future Generation of High Field Magnets

To provide a Schottky junction device having a super-lattice arranged in the Schottky interface in order to secure a high Schottky barrier and at the same time showing a high speed response by resolving the phenomenon of piled-up holes at the upper edge of the valence band, while maintaining the height of the Schottky barrier. A Schottky junction device having a Schottky junction of a semiconductor and a metal and a superlattice on the interface of the semiconductor and the metal, wherein the upper edge of the valence band of said superlattice is varied to show a turn to a specific direction. The phenomenon of hole-piling up at the upper end of the valence band is resolved while maintaining the height of the Schottky barrier and consequently such a Schottky junction device shows an excellent high speed response.

Schottky junction device having a Schottky junction of a semiconductor and a metal

To the Editor: Pyometra, the accumulation of pus within the uterine cavity, is a relatively common event in older females. The cause of pyometra is occlusion of the cervical canal by malignant or benign tumors, surgery, irradiation, or senile cervicitis. A spontaneous perforation of pyometra and subsequent diffuse peritonitis is rare, however, and only 20 cases have been reported in English literature. 1–3 We report two patients that were admitted to our hospital for diffuse peritonitis caused by spontaneously perforated pyometra who underwent operations. Both patients were residents in a nursing home for older people. In older female patients with acute abdominal pain, we should consider this disorder in the differential diagnosis.

Spontaneously perforated pyometra presenting as diffuse peritonitis in older females at nursing homes

This paper describes the successful stacking of multilayered InAs quantum dots (QD) on a GaAs substrate up to 12 layers. The laser oscillated from the ground state under the condition of mirror loss at less than 7–8 cm-1. The extremely low threshold current density per QD-layer of 7 A/cm2/layer was obtained with a lasing wavelength of 1.21 µm at room temperature, which is the lowest value for any known semiconductor laser.

http://iopscience.iop.org/article/10.1143/JJAP.44.L1103/pdf

Hitoshi Shimizu

Papers

Surface-emitting laser element

The CERN FCC Conductor Development Program: A Worldwide Effort for the Future Generation of High Field Magnets

Schottky junction device having a Schottky junction of a semiconductor and a metal

Spontaneously perforated pyometra presenting as diffuse peritonitis in older females at nursing homes

InAs Quantum Dot Lasers with Extremely Low Threshold Current Density (7 A/cm2/Layer)