The Japanese Journal of Applied Physics (JJAP) is an international journal for the advancement and dissemination of knowledge in all fields of applied physics. The journal publishes articles dealing with the applications of physical principles as well as articles concerning the understanding of physics that have particular applications in mind. It is published by IOP Publishing Ltd on behalf of the Japan Society of Applied Physics (JSAP).
This publication is partially supported by a Grant-in-Aid for Publication of Scientific Research Results from the Japan Society for the Promotion of Science.
Congratulations to Isamu Akasaki, Hiroshi Amano and Shuji Nakamura on being awarded the 2014 Nobel Prize for Physics. Several of the key papers cited by the Nobel committee were published in this journal - visit the 2014 Nobel collection to read them for free.
From 2014, JJAP will be published by IOP Publishing on behalf of The Japan Society of Applied Physics. All submissions and refereeing will continue to be handled by the JJAP Editorial Office at The Japan Society of Applied Physics. To submit a paper to JJAP, please connect to the editorial website.
JJAP publishes a number of Special Issues each year. These feature research articles presented at major international conferences. These articles are fully peer-reviewed to JJAP's usual acceptance criteria. Fifteen special issues are planned for 2014. Click here for a list of the 2014 Special Issues.
In the last 30 days
Hiroshi Amano et al 1989 Jpn. J. Appl. Phys. 28 L2112
Distinct p-type conduction is realized with Mg-doped GaN by the low-energy electron-beam irradiation (LEEBI) treatment, and the properties of the GaN p-n junction LED are reported for the first time. It was found that the LEEBI treatment drastically lowers the resistivity and remarkably enhances the PL efficiency of MOVPE-grown Mg-doped GaN. The Hall effect measurement of this Mg-doped GaN treated with LEEBI at room temperature showed that the hole concentration is ∼2·10 16cm -3, the hole mobility is ∼8 cm 2/V·s and the resistivity is ∼35 Ω·cm. The p-n junction LED using Mg-doped GaN treated with LEEBI as the p-type material showed strong near-band-edge emission due to the hole injection from the p-layer to the n-layer at room temperature.
Shuji Nakamura 1991 Jpn. J. Appl. Phys. 30 L1705
High-quality gallium nitride (GaN) film was obtained for the first time using a GaN buffer layer on a sapphire substrate. An optically flat and smooth surface was obtained over a two-inch sapphire substrate. Hall measurement was performed on GaN films grown with a GaN buffer layer as a function of the thickness of the GaN buffer layer. For the GaN film grown with a 200 Å-GaN buffer layer, the carrier concentration and Hall mobility were 4×10 16/cm 3 and 600 cm 2/V·s, respectively, at room temperature. The values became 8×10 15/cm 3 and 1500 cm 2/V·s at 77 K, respectively. These values of Hall mobility are the highest ever reported for GaN films. The Hall measurement shows that the optimum thickness of the GaN buffer layer is around 200 Å.
Kazuhito Hashimoto et al 2005 Jpn. J. Appl. Phys. 44 8269
Photocatalysis has recently become a common word and various products using photocatalytic functions have been commercialized. Among many candidates for photocatalysts, TiO 2 is almost the only material suitable for industrial use at present and also probably in the future. This is because TiO 2 has the most efficient photoactivity, the highest stability and the lowest cost. More significantly, it has been used as a white pigment from ancient times, and thus, its safety to humans and the environment is guaranteed by history. There are two types of photochemical reaction proceeding on a TiO 2 surface when irradiated with ultraviolet light. One includes the photo-induced redox reactions of adsorbed substances, and the other is the photo-induced hydrophilic conversion of TiO 2 itself. The former type has been known since the early part of the 20th century, but the latter was found only at the end of the century. The combination of these two functions has opened up various novel applications of TiO 2, particularly in the field of building materials. Here, we review the progress of the scientific research on TiO 2 photocatalysis as well as its industrial applications, and describe future prospects of this field mainly based on the present authors' work.
Yang Kuo et al 2015 Jpn. J. Appl. Phys. 54 02BD01
First, the experimental implementations and theoretical/numerical investigations of surface plasmon (SP) coupled InGaN/GaN quantum-well light-emitting diodes (LEDs) are reviewed. If the p-GaN layer in an LED can be thin, surface metal nanoparticle (NP) is an inexpensive structure for inducing effective SP coupling. When the p-GaN layer is thick, a few metal structures, including metal protrusion, buried metal NP, and embedded metal NP, can be used for effective SP coupling. In the numerical study, an algorithm, including the feedback effect of the induced SP resonance on the radiating behavior of the source dipole, has been proposed for studying the SP coupling effects with an embedded metal NP, a surface metal NP, and a metal protrusion. Then, the theoretical formulations and numerical algorithms for evaluating the radiated power enhancement in the coupling process between two radiating dipoles and the localized surface plasmon (LSP) induced on a nearby Ag NP are built. Three mechanisms are considered in the coupling process for radiated power enhancement, including the interference of the two phase-retarded radiation contributions from the two dipoles, the interaction between the two dipoles, and the LSP resonant coupling.
Chihaya Adachi 2014 Jpn. J. Appl. Phys. 53 060101
Currently, organic light-emitting diodes (OLEDs) have reached the stage of commercialization, and there are intense efforts to use them in various applications from small- and medium-sized mobile devices to illumination equipment and large TV screens. In particular, phosphorescent materials have become core OLED materials as alternatives to the conventionally used fluorescent materials because devices made with phosphorescent materials exhibit excellent light-emitting performance. However, phosphorescent materials have several problems, such as their structure being limited to organic metal compounds containing rare metals, for example, Ir, Pt, and Os, and difficulty in realizing stable blue light emission, so the development of new materials is necessary. In this article, I will review next-generation OLEDs using a new light-emitting mechanism called thermally activated delayed fluorescence (TADF). Highly efficient TADF, which was difficult to realize with conventional technologies, has been achieved by optimizing molecular structures. This has led to the realization of ultimate next-generation OLEDs that are made of common organic compounds and can convert electricity to light at an internal quantum efficiency of nearly 100%.
Shizuo Fujita 2015 Jpn. J. Appl. Phys. 54 030101
Wide-bandgap semiconductors are expected to be applied to solid-state lighting and power devices, supporting a future energy-saving society. While GaN-based white LEDs have rapidly become widespread in the lighting industry, SiC- and GaN-based power devices have not yet achieved their popular use, like GaN-based white LEDs for lighting, despite having reached the practical phase. What are the issues to be addressed for such power devices? In addition, other wide-bandgap semiconductors such as diamond and oxides are attracting focusing interest due to their promising functions especially for power-device applications. There, however, should be many unknown phenomena and problems in their defect, surface, and interface properties, which must be addressed to fully exploit their functions. In this review, issues of wide-bandgap semiconductors to be addressed in their basic properties are examined toward their “full bloom”.
Mula Sigiro et al 2015 Jpn. J. Appl. Phys. 54 04DH05
We report on the extensive structural and optical studies of Re-doped molybdenum disulfide (MoS 2) grown by the chemical vapor transport (CVT) method using Br 2 as a transport agent. To evaluate the influence of Re on the structural properties of crystals, we have conducted X-ray diffraction (XRD) and transmission electron microscopy (TEM) experiments. For optical characterization, we carried out piezoreflectance (PzR) and electrolyte electroreflectance (EER) measurements. The Re dopant clearly caused a structural change in MoS 2 from a two-layer hexagonal (2H) structure to a three-layer rhombohedral (3R) structure, which has been clearly verified and identified herein.
Shuji Nakamura et al 1991 Jpn. J. Appl. Phys. 30 L1998
High-power p-n junction blue-light-emitting diodes (LEDs) were fabricated using GaN films grown with GaN buffer layers. The external quantum efficiency was as high as 0.18%. Output power was almost 10 times higher than that of conventional 8-mcd SiC blue LEDs. The forward voltage was as low as 4 V at a forward current of 20 mA. This forward voltage is the lowest ever reported for GaN LEDs. The peak wavelength and the full width at half-maximum (FWHM) of GaN LEDs were 430 nm and 55 nm, respectively.
Matiar M. R. Howlader et al 2015 Jpn. J. Appl. Phys. 54 030201
In this paper, surface-activation-based nanobonding technology and its applications are described. This bonding technology allows for the integration of electronic, photonic, fluidic and mechanical components into small form-factor systems for emerging sensing and imaging applications in health and environmental sciences. Here, we describe four different nanobonding techniques that have been used for the integration of various substrates — silicon, gallium arsenide, glass, and gold. We use these substrates to create electronic (silicon), photonic (silicon and gallium arsenide), microelectromechanical (glass and silicon), and fluidic (silicon and glass) components for biosensing and bioimaging systems being developed. Our nanobonding technologies provide void-free, strong, and nanometer scale bonding at room temperature or at low temperatures (<200 °C), and do not require chemicals, adhesives, or high external pressure. The interfaces of the nanobonded materials in ultra-high vacuum and in air correspond to covalent bonds, and hydrogen or hydroxyl bonds, respectively.
Dirk Taillaert et al 2006 Jpn. J. Appl. Phys. 45 6071
Nanophotonic waveguides and components are promising for use in the large-scale integration of photonic circuits. Coupling light between nanophotonic waveguides and a single-mode fiber is an important problem and many different solutions have been proposed and demonstrated in recent years. In this paper, we discuss a grating coupler approach. Grating couplers can be placed anywhere on a circuit and can easily be integrated. We have experimentally demonstrated >30% coupling efficiency with a 1 dB bandwidth of 40 nm on standard wafers. Theoretically, the coupling efficiency can be improved to >90% using an optimized grating design and layer stack. The fabrication of the couplers in silicon-on-insulator and in indium phosphide membranes is also discussed.
This cloud represents the 50 most popular PACS codes from the latest 250 coded articles for this journal. The larger the code the more times it occurs in those 250 articles. Click on a code to link to the articles in that category.
64.70.kg 68.37.Rt 61.72.sh 52.20.Fs 42.15.Eq 71.15.Mb 42.65.Pc 42.79.Ta 68.65.Cd 72.20.Pa 41.85.Lc 68.35.Gy 02.50.Fz 42.79.Sz 52.65.-y 62.20.D- 44.10.+i 42.79.Qx 52.77.Bn 52.38.-r 52.30.-q 52.80.Pi 72.15.Jf 66.70.Df 52.50.Qt 72.60.+g 52.80.Mg 72.15.Eb 42.65.Re 42.81.-i 61.72.Ff 42.70.Jk 72.80.Ey 61.05.cp 61.80.Jh 65.40.G- 42.81.Pa 07.07.Df 52.70.Kz 68.43.Fg 52.58.-c 52.77.Dq 52.25.-b 72.20.Dp 42.60.Da 52.40.Fd 42.79.Ci 29.25.Bx 07.55.Ge 71.55.Ht