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.
2016 Japan Prize honours trailblazer Hideo Hosono
The Japan Society of Applied Physics and IOP Publishing would like to extend their congratulations to Professor Hideo Hosono, who has been awarded the Japan Prize for the "creation of unconventional inorganic materials with novel electronic functions based on nano-structure engineering".
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JSAP Outstanding Paper Awards
The Japan Society of Applied Physics is pleased to announce the recipients of the latest JSAP Outstanding Paper Awards. These awards honour the authors of papers that are regarded as exceptional achievements in applied physics. The successful papers may be viewed here and are free to read until July 31st, 2016.
The Japan Society of Applied Physics (JSAP) is pleased to announce that the Creative Commons license "CC BY" will be applied to Open Select articles to be published in Applied Physics Express (APEX) and Japanese Journal of Applied Physics (JJAP). In accordance with the policy, the copyright of Open Select articles shall belong to the authors. This policy may be retroactively applied to existing Open Select articles from July 10, 2015 with the authors' agreement.
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.
In the last 30 days
Shintaro Sato 2015 Jpn. J. Appl. Phys. 54 040102
Graphene is a two-dimensional material with a one-atom-thick layer of carbon. Since the first report of the excellent electrical properties of graphene in 2004, its unique physical properties have been attracting attention and research on the application of graphene to electronic and photonic devices has been intensively carried out. In this review, recent research trends in the application of graphene to electronic devices, particularly transistors and interconnects, and graphene formation techniques are examined. In addition, the technical issues to be addressed for its application to electronic devices and the prospects for future graphene devices are discussed.
Md. Shahiduzzaman et al 2016 Jpn. J. Appl. Phys. 55 02BF05
Hybrid organic/inorganic perovskites such as methylammonium lead iodide (CH 3NH 3PbI 3) are potential candidates for thin-film photovoltaics because of their excellent cost- and energy-efficient light absorption. In this work, we have prepared CH 3NH 3PbI 3 nanoparticles (NPs) on the TiO x /ITO glass substrates by a simple spin-coating method to control the size and shape of NPs. The effect of varying the weight percentage (wt %) of ionic liquid (IL) has also been investigated. Analysis of the films revealed spherical NP morphology in the presence of 1, 3, and 7 wt % IL with respective diameters of 540, 350, and 600 nm. Conversely, 10 wt % IL resulted in irregular aggregation of NP blocks. The power conversion efficiency (PCE) changed upon varying the NP size, shape, and morphology. The optimization of the concentration with 3 wt % IL yielded NPs with the most uniform shape, size, and morphology and, consequently, the maximum PCE.
Vincent Obiozo Eze et al 2016 Jpn. J. Appl. Phys. 55 02BF08
There is a multitude of reports on different methods of fabricating organic–inorganic halide perovskite films for high-efficiency solar cells. In this study, planar heterojunction (PHJ) CH 3NH 3PbI 3 perovskite solar cells were prepared by the two-step spin-coating method. The uniformity of the perovskite light-absorbing layer is enhanced by air-assisted flow (AAF). We compared the photovoltaic performance characteristics of films prepared with and without AAF. Perovskite solar cells constructed without AAF showed a power conversion efficiency (PCE) of 8.67%, whereas a higher PCE of 13.28% was obtained with an AAF-based perovskite solar cell. Our study presents a useful technique for preparing high-quality perovskite films.
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.
D. Martin Taylor 2016 Jpn. J. Appl. Phys. 55 02BA01
This review article focuses on the development of processes for the manufacture of organic electronic circuits. Beginning with the first report of an organic transistor it highlights the key developments leading to the successful manufacture of microprocessors and other complex circuits incorporating organic transistors. Both batch processing (based on silicon integrated circuit technology) as well as mass-printing, roll-to-roll (R2R) approaches are discussed. Currently, the best circuit performances are achieved using batch processing. It is suggested that an emerging, large mass-market for electronic tags may dictate that R2R manufacture will likely be required to meet the high throughput rates needed. However, significant improvements in resolution and registration are necessary to achieve increased circuit operating speeds.
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”.
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.
Masanori Hangyo 2015 Jpn. J. Appl. Phys. 54 120101
Recently, the technology of terahertz (THz) waves, which have been called undeveloped electromagnetic waves, has been making remarkable progress. In addition to the technologies of generating THz waves using lasers, which are promoting this progress, advances are being made in THz generation methods using electronic devices and accelerators, and various THz optical components have been actively developed. The applications of THz technology are also becoming increasingly widespread. In this report, I will review these developments and discuss the future prospects of this field.
2016 Jpn. J. Appl. Phys. 55 01A001
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%.