Yoshiji Horikoshi

Bio: Yoshiji Horikoshi is an academic researcher from Waseda University. The author has contributed to research in topics: Epitaxy & Molecular beam epitaxy. The author has an hindex of 40, co-authored 363 publications receiving 6574 citations. Previous affiliations of Yoshiji Horikoshi include Nippon Telegraph and Telephone.

Low-Temperature Growth of GaAs and AlAs-GaAs Quantum-Well Layers by Modified Molecular Beam Epitaxy

Abstract: When Ga or Al atoms are evaporated on a clean GaAs surface in an As-free atmosphere, they are quite mobile and migrate very rapidly along the surface even at low temperatures. This characteristic are utilized for growing high-quality GaAs and AlAs layers at very low temperatures by alternately supplying Ga or Al atoms and As4 molecules to the GaAs substrate. Applying this method, GaAs layers and AlAs–GaAs quantum well structures with reasonable photoluminescence characteristics are grown at 200°C and 300°C, respectively.

Migration-Enhanced Epitaxy of GaAs and AlGaAs

Abstract: Surface migration is effectively enhanced by evaporating Ga or Al atoms onto a clean GaAs surface under an As-free or low As pressure atmosphere. This characteristic was utilized by alternately supplying Ga and/or Al and AS4 to the substrate surface for growing atomically-flat GaAs-AlGaAs heterointerfaces, and also for growing high-quality GaAs and AlGaAs layers at very low substrate temperatures. The migration characteristics of surface adatoms have been investigated through reflection high-energy electron diffraction measurements. It was found that different growth mechanisms are operative in this method at both high and low temperatures. Both these mechanisms are expected to yield flat heterojunction interfaces. By applying this method, GaAs layers and GaAs-AlGaAs single quantum-well structures with excellent photoluminescence were grown at substrate temperatures of 200 and 300degC, respectively.

Abrupt p‐type doping profile of carbon atomic layer doped GaAs grown by flow‐rate modulation epitaxy

Abstract: Atomic layer doping of p‐type carbon impurity in GaAs was demonstrated using flow‐rate modulation epitaxy An extremely narrow capacitance‐voltage profile with 58 nm full width at half‐maximum is observed in the wafer with a sheet hole density of 95×1011 cm−2 Atomic layer doping of carbon was performed by supplying trimethylgallium or trimethylaluminium instead of triethylgallium It was found that the sheet hole density does not change before and after annealing for 1 h at 800 °C indicating that the carbon is a very stable impurity in GaAs The diffusion coefficient of carbon is estimated to be 2×10−16 cm−2/s at 800 °C This is the lowest value ever reported for p‐type impurities

Temperature Sensitive Threshold Current of InGaAsP-InP Double Heterostructure Lasers

Abstract: The threshold current of InGaAsP–InP double hetetostructure lasers has been investigated through measurements of the temperature dependence of carrier lifetime and radiative efficiency. Both the carrier lifetime and the radiative efficiency decrease noticeably above the break point temperature as observed in the Ith vs. T relation. The decrease of the carrier lifetime is explained by considering additional non-radiative recombination centers with 0.3 eV activation energy. The origin of this center is also discussed.

A comprehensive review of zno materials and devices

Abstract: The semiconductor ZnO has gained substantial interest in the research community in part because of its large exciton binding energy (60meV) which could lead to lasing action based on exciton recombination even above room temperature. Even though research focusing on ZnO goes back many decades, the renewed interest is fueled by availability of high-quality substrates and reports of p-type conduction and ferromagnetic behavior when doped with transitions metals, both of which remain controversial. It is this renewed interest in ZnO which forms the basis of this review. As mentioned already, ZnO is not new to the semiconductor field, with studies of its lattice parameter dating back to 1935 by Bunn [Proc. Phys. Soc. London 47, 836 (1935)], studies of its vibrational properties with Raman scattering in 1966 by Damen et al. [Phys. Rev. 142, 570 (1966)], detailed optical studies in 1954 by Mollwo [Z. Angew. Phys. 6, 257 (1954)], and its growth by chemical-vapor transport in 1970 by Galli and Coker [Appl. Phys. ...

Band parameters for III–V compound semiconductors and their alloys

Abstract: We present a comprehensive, up-to-date compilation of band parameters for the technologically important III–V zinc blende and wurtzite compound semiconductors: GaAs, GaSb, GaP, GaN, AlAs, AlSb, AlP, AlN, InAs, InSb, InP, and InN, along with their ternary and quaternary alloys. Based on a review of the existing literature, complete and consistent parameter sets are given for all materials. Emphasizing the quantities required for band structure calculations, we tabulate the direct and indirect energy gaps, spin-orbit, and crystal-field splittings, alloy bowing parameters, effective masses for electrons, heavy, light, and split-off holes, Luttinger parameters, interband momentum matrix elements, and deformation potentials, including temperature and alloy-composition dependences where available. Heterostructure band offsets are also given, on an absolute scale that allows any material to be aligned relative to any other.

Making Nonmagnetic Semiconductors Ferromagnetic

Abstract: REVIEW Semiconductor devices generally take advantage of the charge of electrons, whereas magnetic materials are used for recording information involving electron spin. To make use of both charge and spin of electrons in semiconductors, a high concentration of magnetic elements can be introduced in nonmagnetic III-V semiconductors currently in use for devices. Low solubility of magnetic elements was overcome by low-temperature nonequilibrium molecular beam epitaxial growth, and ferromagnetic (Ga,Mn)As was realized. Magnetotransport measurements revealed that the magnetic transition temperature can be as high as 110 kelvin. The origin of the ferromagnetic interaction is discussed. Multilayer heterostructures including resonant tunneling diodes (RTDs) have also successfully been fabricated. The magnetic coupling between two ferromagnetic (Ga,Mn)As films separated by a nonmagnetic layer indicated the critical role of the holes in the magnetic coupling. The magnetic coupling in all semiconductor ferromagnetic/nonmagnetic layered structures, together with the possibility of spin filtering in RTDs, shows the potential of the present material system for exploring new physics and for developing new functionality toward future electronics.

GaAs, AlAs, and AlxGa1−xAs: Material parameters for use in research and device applications

Abstract: The Al x Ga1−x As/GaAs heterostructure system is potentially useful material for high‐speed digital, high‐frequency microwave, and electro‐optic device applications Even though the basic Al x Ga1−x As/GaAs heterostructure concepts are understood at this time, some practical device parameters in this system have been hampered by a lack of definite knowledge of many material parameters Recently, Blakemore has presented numerical and graphical information about many of the physical and electronic properties of GaAs [J S Blakemore, J Appl Phys 5 3, R123 (1982)] The purpose of this review is (i) to obtain and clarify all the various material parameters of Al x Ga1−x As alloy from a systematic point of view, and (ii) to present key properties of the material parameters for a variety of research works and device applications A complete set of material parameters are considered in this review for GaAs, AlAs, and Al x Ga1−x As alloys The model used is based on an interpolation scheme and, therefore, necessitates known values of the parameters for the related binaries (GaAs and AlAs) The material parameters and properties considered in the present review can be classified into sixteen groups: (1) lattice constant and crystal density, (2) melting point, (3) thermal expansion coefficient, (4) lattice dynamic properties, (5) lattice thermal properties, (6) electronic‐band structure, (7) external perturbation effects on the band‐gap energy, (8) effective mass, (9) deformation potential, (10) static and high‐frequency dielectric constants, (11) magnetic susceptibility, (12) piezoelectric constant, (13) Frohlich coupling parameter, (14) electron transport properties, (15) optical properties, and (16) photoelastic properties Of particular interest is the deviation of material parameters from linearity with respect to the AlAs mole fraction x Some material parameters, such as lattice constant, crystal density, thermal expansion coefficient, dielectric constant, and elastic constant, obey Vegard’s rule well Other parameters, eg, electronic‐band energy, lattice vibration (phonon) energy, Debye temperature, and impurity ionization energy, exhibit quadratic dependence upon the AlAs mole fraction However, some kinds of the material parameters, eg, lattice thermal conductivity, exhibit very strong nonlinearity with respect to x, which arises from the effects of alloy disorder It is found that the present model provides generally acceptable parameters in good agreement with the existing experimental data A detailed discussion is also given of the acceptability of such interpolated parameters from an aspect of solid‐state physics Key properties of the material parameters for use in research work and a variety of Al x Ga1−x As/GaAs device applications are also discussed in detail

Diode Lasers and Photonic Integrated Circuits

Abstract: Ingredients. A Phenomenological Approach to Diode Lasers. Mirrors and Resonators for Diode Lasers. Gain and Current Relations. Dynamic Effects. Perturbation and Coupled--Mode Theory. Dielectric Waveguides. Photonic Integrated Circuits. Appendices. Index.