著者
Horike Shohei Misaki Masahiro Koshiba Yasuko Morimoto Masahiro Saito Takeshi Ishida Kenji
出版者
Institute of Physics
雑誌
Appl. Phys. Express (ISSN:18820778)
巻号頁・発行日
vol.9, no.8, 2016-07-06
被引用文献数
9

The tuning of the Seebeck coefficient of a single-walled carbon nanotube (SWCNT) film was achieved by using the dipole field of a ferroelectric polymer. The Seebeck coefficient was positive under an up-poling dipole field, but negative under a down-poling dipole field, whereas the control remained positive. This tunable behavior can be explained by selective carrier injection and accumulation, which was confirmed by the temperature dependence of electrical conductivity. Connecting p- and n-type SWCNT films tuned by dipole fields to create a π module resulted in a significant improvement in output voltage owing to the temperature difference between the two.
著者
Morgan Daniel Sultana Mahbuba Fatima Husna Sugiyama Sho Fareed Qhalid Adivarahan Vinod Lachab Mohamed Khan Asif
出版者
The Japan Society of Applied Physics
雑誌
Applied physics express (ISSN:18820778)
巻号頁・発行日
vol.4, no.11, pp.114101-114101-3, 2011-11-25
被引用文献数
1 23

This letter presents the dc characteristics of normally Off AlInN/AlN/GaN metal--oxide--semiconductor heterostructure field-effect transistors (MOS-HFETs). The devices were fabricated using a recessed gate and SiON dielectric layers for gate isolation. For a device with a 1.5 μm gate length and an 8-μm-long channel, the threshold voltage was above +1.5 V and a maximum drain current density of 0.7 A/mm was reached under 6 V gate bias. These enhancement-mode MOS-HFETs have an excellent potential for power electronics applications.
著者
Inoue Takaaki Mori Akimitsu Koshiba Yasuko Misaki Masahiro Ishida Kenji
出版者
Institute of Physics
雑誌
Appl. Phys. Express (ISSN:18820778)
巻号頁・発行日
vol.8, no.11, 2015-10-14
被引用文献数
3

The ferroelectric properties of perpendicularly oriented, highly crystalline vinylidene fluoride (VDF) oligomer thin films were investigated by using a planar device configuration consisting of comblike Cr–Au electrodes with a 1 µm gap. In-plane polarization switching was induced by the rotation of the VDF oligomer. As the measurement temperature was increased from 295 to 380 K, the coercive field (E<inf>c</inf>) decreased drastically from 124 to 7.7 MV/m. Furthermore, the thermal stability of our device significantly improved compared with that of conventional sandwiched devices utilizing VDF oligomer films with a parallel orientation.
著者
Kasai Seiya Ichiki Akihisa Tadokoro Yukihiro
出版者
IOP Publishing
雑誌
Applied Physics Express (APEX) (ISSN:18820778)
巻号頁・発行日
vol.11, no.3, pp.037301, 2018-03
被引用文献数
8

A bistable system efficiently detects a weak signal by adding noise, which is referred to as stochastic resonance. A previous theory deals with friction in state transition; however, this hypothesis is inadequate when friction force is negligible such as in nano-and molecular-scale systems. We show that, when the transition occurs without friction, the sensitivity of the bistable system to a Gaussian-noise-imposed weak signal becomes significantly high. The sensitivity is determined by the relative difference in noise distribution function. We find that the relative difference in Gaussian distribution function diverges in its tail edge, resulting in a high sensitivity in the present system. (C) 2018 The Japan Society of Applied Physics
著者
Song Min Yeong Seo Yujeong Kim Yeon Soo Kim Hee Dong An Ho-Myoung Park Bae Ho Sung Yun Mo Kim Tae Geun
出版者
The Japan Society of Applied Physics
雑誌
Applied Physics Express (ISSN:18820778)
巻号頁・発行日
vol.5, no.9, pp.91202-091202-3, 2012-09-25
被引用文献数
20

The authors report a silicon-based one-diode--type resistive-switching memory (RRAM) device with self-rectifying properties and high electrical properties. The RRAM cell consisted of Al/Cr--SrTiO3/Si and revealed intrinsic diode properties, so that unwanted sneaky currents could be removed from an RRAM crossbar array without extra switching devices. The insulator--metal transition property of the proposed device was explained using the space-charge--limited conduction mechanism. The memory device showed good characteristics including high ON/OFF ratio ({\sim}10^{6}), low reset current ({\sim}10^{-11} A), high speed at low voltage (200 ns, 2 V), and reasonable endurance ({>}10^{4} cycles) and retention characteristics ({>}10^{4} s).

1 0 0 0 CuSbSe

著者
Welch Adam Baranowski Lauryn Zawadzki Pawel Lany Stephan Wolden Colin Zakutayev Andriy
出版者
Institute of Physics
雑誌
Appl. Phys. Express (ISSN:18820778)
巻号頁・発行日
vol.8, no.8, 2015-07-06
被引用文献数
80

Recent technical and commercial successes of existing thin-film solar cell technologies encourage the exploration of next-generation photovoltaic (PV) absorber materials. Of particular scientific interest are compounds that do not exhibit conventional tetrahedral semiconductor bonding, such as CuSbSe<inf>2</inf>. CuSbSe<inf>2</inf>has a 1.1 eV optical absorption onset, a 10<sup>5</sup>cm<sup>−1</sup>absorption coefficient, and a hole concentration of 10<sup>17</sup>cm<sup>−3</sup>. Here, we demonstrate CuSbSe<inf>2</inf>PV prototypes with efficiencies >3%, prepared by a self-regulated sputtering process using a conventional substrate device architecture. Bulk recombination, device engineering issues, and a nonideal CuSbSe<inf>2</inf>/CdS band offset likely limit the promising initial result.
著者
Takahashi Hideyuki Okamoto Tsubasa Ohmichi Eiji Ohta Hitoshi
出版者
Institute of Physics
雑誌
Appl. Phys. Express (ISSN:18820778)
巻号頁・発行日
vol.9, no.12, 2016-10-27
被引用文献数
8

We present a method of broadening the dynamic range of optical interferometric detection of cantilever displacement. The key idea of this method is the use of a wavelength-tunable laser source. The wavelength is subject to proportional-integral control, which is used to keep the cavity detuning constant. Under this control, the change in wavelength is proportional to the cantilever displacement. Using this technique, we can measure large displacements (>1 µm) without degrading the sensitivity. We apply this technique to high-frequency electron spin resonance spectroscopy and succeed in removing an irregular background signal that arises from the constantly varying sensitivity of the interferometer.
著者
Kojima Osamu Kita Takashi
出版者
Japan Society of Applied Physics
雑誌
Appl. Phys. Express (ISSN:18820778)
巻号頁・発行日
vol.9, no.6, 2016-05-09
被引用文献数
2

In this study, we report the effects of the exciton line widths on the amplitude of quantum beat oscillations using a model with the Voigt function. Using the Voigt function, we find that the maximum amplitude appears at the central energy between two excitons. This result agrees with many previous experimental results. Our analysis helps in identifying the condition for strong quantum beat oscillation, which is important for device applications such as terahertz electromagnetic wave emitters and ultrafast switches.
著者
Morimoto Masahiro Koshiba Yasuko Misaki Masahiro Ishida Kenji
出版者
Institute of Physics
雑誌
Appl. Phys. Express (ISSN:18820778)
巻号頁・発行日
vol.8, no.10, 2015-10-01
被引用文献数
12

We have investigated the temperature dependence of the piezoelectric coefficients and infrared sensor performance of spin-coated thin films of polyundecylurea (PUA11). The piezoelectric coefficients of the PUA11 films remained constant at temperatures above 180 °C and these films demonstrated thermal resistance superior to those of poly(vinylidene fluoride/trifluoroethylene) [P(VDF/TrFE)] films. The infrared sensor performance of the PUA11 films was measured after annealing at 125 °C for 500 h and was found to have retained 84% of its preannealing level. The thermal stability of the PUA11 films was higher than that of the P(VDF/TrFE) films; moreover, PUA11 is also expected to have superior electrothermal stability.
著者
Hayashi Shinji Nesterenko Dmitry Sekkat Zouheir
出版者
Institute of Physics
雑誌
Appl. Phys. Express (ISSN:18820778)
巻号頁・発行日
vol.8, no.2, 2015-01-06
被引用文献数
84

A planar multilayer structure that allows coupling between surface plasmon polaritons and waveguide modes is proposed. Calculated reflectivity curves exhibit sharp resonances due to the Fano resonance and plasmon-induced transparency arising from the coupling. Electric field profiles obtained at the resonances demonstrate the hybrid nature of the modes excited. When the Fano resonance is used for sensing, the sensitivity with intensity modulation is enhanced by two orders of magnitude relative to that of conventional surface plasmon resonance sensors.
著者
Recht Daniel Hutchinson David Cruson Thomas DiFranzo Anthony McAllister Andrew Said Aurore J. Warrender Jeffrey M. Persans Peter D. Aziz Michael J.
出版者
The Japan Society of Applied Physics
雑誌
Applied physics express (ISSN:18820778)
巻号頁・発行日
vol.5, no.4, pp.41301-041301-3, 2012-04-25
被引用文献数
7

Photoconductivity in silicon hyperdoped with sulfur and selenium above the insulator-to-metal transition was measured via photoinduced changes in the microwave reflectivity of hyperdoped layers formed on p-type silicon. Despite these materials' strong subgap optical absorption, exposing them to 1310 and 1550 nm light results in a change in conductivity per photon 10,000 times smaller than what is observed in untreated silicon exposed to 980 nm light. A similar bound applies for 405 nm light, which is absorbed entirely in the hyperdoped layer. We use these results to deduce that the photocarrier lifetime in the hyperdoped material is {\leq}100 ns.