S. Aihara, M. Hamamoto, K. Iwamitsu, M. Okada, I. Akai
AIP Advances 7 2017年4月 [査読有り]
? 2017 Author(s). By Bayesian inference with Metropolis algorithm, we have succeeded highly accurate estimation of a vibrational frequency as well as an initial phase for a damped oscillation contained in coherent phonon signals. Although a rise a...
S. Aihara, A. Ota, K. Iwamitsu, K. Iwamitsu, F. Ichikawa, H. Isobe, T. Shimamoto, I. Akai
Journal of Luminescence 167 211-215 2015年7月 [査読有り]
? 2015 Elsevier B.V. Abstract We investigated biaxial stress effects on the yellow 1S ortho excitons in Cu < inf > 2 < /inf > O thin films recrystallized between paired MgO plates by measuring photoluminescence spectra, X-ray diffraction and polar...
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN 83(12) 1-147427 2014年12月 [査読有り]
? 2014 The Physical Society of Japan. We investigated the stress effects on nP yellow excitons in Cu 2 O thin films recrystallized epitaxially in a sample gap between paired MgO substrates. In such samples, it is expected that a two-dimensional co...
EUROPEAN PHYSICAL JOURNAL B 86(5) 1-6 2013年5月 [査読有り]
We have investigated stress effects on yellow exciton states in a Cu 2 O thin film sandwiched by MgO plates by measuring wavelength modulated (WM) absorption spectra and their thermal variations. In the WM absorption spectra, dispersive spectral s...
PHYSICA STATUS SOLIDI C: CURRENT TOPICS IN SOLID STATE PHYSICS, VOL 9, NO 12 9(12) 2489-2492 2012年12月 [査読有り]
In order to clarify uniaxial stress effects on a green excitonic series in Cu 2 O, we measured temperature dependence of wavelength modulated (WM) absorption spectra of a Cu 2 O thin film sandwiched by MgO plates. In these spectra, excitonic reson...
PHYSICA STATUS SOLIDI C: CURRENT TOPICS IN SOLID STATE PHYSICS, VOL 9, NO 12 9(12) 2509-2512 2012年12月 [査読有り]
We investigated high density excitation effects in propagation and diffusion processes of free excitons confined in an L z -gradient GaAs quantum well (QW). From measurements of μPL spectra, it was found that driving force owing to a confined-ener...
K. Iwamitsu, S. Aihara, T. Shimamoto, A. Fujii, and I. Akai
Review of Scientific Instruments 83(7) 2012年7月 [査読有り]
We developed a newly designed wavelength modulation (WM) system for highly sensitive absorption spectroscopy. In our system, the WM is realized by yawing an output mirror in a monochromator. In order to control an amplitude Δλ of the WM in a wide ...
Physics reports of the Kumamoto University 14(1) 41-51 2012年
We investigated temperature dependence of wavelength modulated (WM) absorptionspectra for studying stress effects on a Cu2O thin film. In these spectra, 2P?4P spectralstructures can be clearly detected in both yellow and green excitons even at 180...
Excitons, photocarriers, and bias-induced carriers in regioregular poly(3-alkylthiophene) (P3AT) films were investigated using a variety of spectroscopic techniques, such as continuous-wave- (cw-) and femtosecond (fs-) transient photoinduced absor...
Synthetic supermolecules such as π -conjugated light-harvesting dendrimers efficiently harvest energy from sunlight, which is of significant importance for the global energy problem. Key to their success is rapid transport of electronic excitation...
PHYSICA STATUS SOLIDI C: CURRENT TOPICS IN SOLID STATE PHYSICS, VOL 8, NO 1 8(1) 58-61 2011年1月 [査読有り]
From analyses of molecular vibrations, we have studied rapid energy transfer (ET) process in a series of star-shaped stilbenoid phthalocyanines (SSSnPc;n=1,2) having π-conjugated light harvesting antennas. In SSSnPc, the highly efficient ET occurs...
PHYSICA STATUS SOLIDI C: CURRENT TOPICS IN SOLID STATE PHYSICS, VOL 8, NO 1 8(1) 155-158 2011年1月 [査読有り]
We investigated rapid energy transfer (ET) processes in dendrimers having meta -linked branching light harvesting antennas. It was found that, at room temperature (RT), the rapid ET occurs efficiently from the antennas to the core and gives rise t...
We have performed spectroscopic measurements combining with the diode operation of [6,6]-phenyl C61 butyric acid methyl ester (PCBM) for directly characterizing the nature of its n -carriers. The measurements in the visible region reveal that elec...
Physics reports of the Kumamoto University 13(2) 333-340 2010年
We investigated rapid energy transfer (ET) processes in dendrimers having meta-linked branching light harvesting antennas. It was found that, at room temperature (RT), the rapid ET occurs efficiently from the antennas to the core and gives rise to...
A. Yamada, A. Ishida, I. Akai, M. Kimura, I. Katayama, J. Takeda
Journal of Luminescence 129 1898-1900 2009年12月 [査読有り]
Rapid energy transfer dynamics in light-harvesting small dendrimers (star-shaped stilbenoid phthalocyanine: SSS2Pc-m, m=1,2) having different numbers of oligo(p-phenylenevinylene) periphery antennas was studied by time-frequency two-dimensional (2...
Bleaching probe spectroscopy performed for regioregular poly(3-hexylthiophene) diodes reveals that coexistent morphological phases determine the conducting and optical properties of conjugated polymer films. Photoinduced absorption measurements de...
JOURNAL OF CHEMICAL PHYSICS 130(23) 234909 2009年6月 [査読有り]
Temperature dependences (4-300 K) of photoluminescence (PL) and absorption spectra of 16-mer oligothiophene (16 T) extremely diluted in polypropylene (PP) have been investigated in order to clarify temperature effects on quasi-isolated conjugated ...
PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS 246(6) 1327-1333 2009年6月 [査読有り]
Decay kinetics of the luminescence of Ag - centers doped in NaCl, KBr, and CsBr single crystals have been investigated in the temperature range from 4 K to 260 K. At low temperature, the radiative transitions from the 1 T 1u states in the Ag - ...
PHYSICA STATUS SOLIDI C - CURRENT TOPICS IN SOLID STATE PHYSICS, VOL 6, NO 1 6(1) 193-+ 2009年4月 [査読有り]
The temperature dependence (4 K-300 K) of the photoluminescence (PL) and absorption spectra of 16-mer oligothiophene (16T) diluted in polypropylene (PP) with a weight ratio of 1/30000 has been investigated in order to clarify the intrinsic tempera...
I. Akai, K. Miyanari, T. Shimamoto, A. Fujii, H. Nakao, A. Okada, K. Kanemoto, T. Karasawa, A. Ishida, A. Yamada, I. Katayama, J. Takeda, M. Kimura
physica status solidi (c) 6(1) 77-80 2009年4月 [査読有り]
We investigate a rapid energy transfer (ET) process and its temperature dependence in a star-shaped stilbenoid phthalocyanine (SSS1Pc) dendrrimer having πconjugated light-harvesting (LH) antennas. In SSS1Pc, intense core-photoluminescence is obser...
Akai Ichiro, Miyanari K., Shimamoto T., Fujii A., Nakao H., Okada A., Kanemoto K., Karasawa T., Ishida A., Yamada A., Katayama I., Takeda J., Kimura M., アカイ イチロウ, 赤井 一郎
Physica status solidi. C 6(1) 77-80 2009年1月
We investigate a rapid energy transfer (ET) process and its temperature dependence in a star-shaped stilbenoid phthalocyanine(SSS1Pc) dendrimer having π-conjugated light-harvesting (LH) antennas. In SSS1Pc, intense corephotoluminescenceis observed...
Akai Ichiro, Miyanari K., Shimamoto T., Fujii A., Nakao H., Okada A., Kanemoto K., Karasawa T., Hashimoto H., Ishida A., Yamada A., Katayama I., Takeda J., Kimura M., アカイ イチロウ, 赤井 一郎
New Journal of Physics 10 2008年12月
We investigate rapid energy transfer (ET) and its temperature dependence in a star-shaped stilbenoid phthalocyanine (SSS1Pc) dendrimer having π-conjugated light-harvesting (LH) antennas, and develop an appropriate model. In SSS1Pc, an intense core...
A. Ishida, Y. Makishima, A. Okada, I. Akai, K. Kanemoto, T. Karasawa, M. Kimura, J. Takeda
Journal of Luminescence 128(5月6日) 771-773 2008年5月 [査読有り]
Rapid energy transfer dynamics in light-harvesting small dendrimers (star-shaped stilbenoid phthalocyanine: SSS1-Pc) having oligo (p-phenylenevinylene) peripheries was studied by real-time pump-probe imaging spectroscopy implemented on a single-sh...
Energy transfer and shielding effect are studied in wire-type dendrimers (GnPPV: n-thgeneration dendrimer with poly(p-phenylenevinylene) backbone; n = 1, 2) havingoligophenylene light-harvesting (LH) antenna. Following the excitation of the LH-ant...
JOURNAL OF PHYSICAL CHEMISTRY B 111(43) 12389-12394 2007年11月 [査読有り]
The photoluminescence (PL) dynamics of poly[2-methoxy-5-(2′-ethyl- hexyloxy)-1,4-phenylene vinylene] (MEH-PPV) blended in host polymer (polypropylene, PP) matrix as well as that in the neat film has been studied. The concentration of MEH-PPV in th...
V.F. Agekyan, I. Akai, N.G. Filosofov, T. Karasawa, G. Karczewski, A. Yu. Serov, N.N. Vasiliev
physica status solidi (b) 244(9) 3265-3270 2007年9月 [査読有り]
The effect of excitation level on the luminescence of ZnMnTe/ZnMgTe quantum-well (QW) structures has been studied. We find that result depend strongly on the QW width and manganese concentration. The increasing optical pumping implies a degradatio...
Physics of the Solid State 49(6) 1175-1183 2007年6月 [査読有り]
The emission spectra of Zn 1-x Mn x Te/Zn 0.6 Mg 0.4 Te and Cd 1-x Mn x Te/Cd 0.5 Mg 0.5 Te quantum-well structures with different manganese concentrations and quantum-well widths are studied at excitation power densities ranging from 10 5 to 10 7...
JOURNAL OF PHYSICS-CONDENSED MATTER 19(13) 1-9 2007年4月 [査読有り]
Luminescence properties including decay kinetics have been investigated for Ag - centres doped in NaCl single crystals in the temperature range from 7 to 250K. When the C absorption band peaking at 4.5eV is photo-excited at low temperature, the A...
I. Akai, T. Kato, A. Okada, K. Kanemoto, T. Karasawa, M. Kimura, M. Ohashi, S. Shinoda, H. Tsukube
physica status solidi (c) 3(10) 3414-3419 2006年12月 [査読有り]
The temperature dependence of excitonic energy transfer is investigated in both small and large dendrimers having meta-linked light-harvesting peripheries. In these dendrimers, highly efficient excitonic energy transfer takes place from peripherie...
I. Akai, T. Kato, K. Kanemoto, T. Karasawa, M. Ohashi, S. Shinoda, and H. Tsukube
physica status solidi (c) 3(10) 3420-3425 2006年12月 [査読有り]
Morphology dependence of excitonic energy transfer in light-harvesting dendrimers (4thmQ: m = 1, 3, and 4) with fourth branching generation is investigated from the measurements of photoluminescence (PL) spectra and the 1 H-NMR spin-spin relaxati...
I. Akai, A. Okada, K. Kanemoto, T. Karasawa, H. Hashimoto, M. Kimura
Journal of Luminescence 119 283-287 2006年7月 [査読有り]
Temperature dependence of the energy-transfer dynamics in a light-harvesting small dendrimer (star-shaped stilbenoid phthalocyanine: SSS1Pc) having oligo (p-phenylenevinylene) peripheries is investigated. We measured stationary and time-resolved p...
K. Kanemoto, T. Sudo, I. Akai, H. Hashimoto, T. Karasawa, Y. Aso, T. Otsubo
Physical Review B 73(23) 1-235203 2006年6月 [査読有り]
The intrinsic intrachain photoluminescence (PL) dynamics of conjugated polymers in the solid state is investigated. We focus on the PL properties of long β -substituted oligothiophenes (8-mer, 12-mer, and 16-mer) and regio-regular (RR) and regio-r...
K. Kanemoto, M. Shishido, T. Sudo, I. Akai, T. Karasawa, Y. Agari
Synthetic Metals 155(1) 162-167 2005年10月 [査読有り]
Optical properties on the basis of absorption and photoluminescence (PL) have been examined for regioregular (RR-) poly(3-octylthiophene) (P3OT) and regiorandom (RRa-) P3OT diluted in polypropylene (PP). RR-P3OT gives blue-shifted spectra in both ...
H. Xie, I. Kinoshita, T. Karasawa, K. Kimura, T. Nishioka, I. Akai, K. Kanemoto
The Journal of Physical Chemistry B 109(19) 9339-9345 2005年5月 [査読有り]
The structure of hexanuclear 6-methyl-2-pyridinethiolato copper(I) [Cu 6 (6-mpyt) 6 ] crystals has been studied by the X-ray diffraction analysis. These crystals show highly efficient luminescence whose color changes drastically from red to green...
I. Akai, H. Nakao, K. Kanemoto, T. Karasawa, H. Hashimoto, M. Kimura
Journal of Luminescence 112(1月4日) 449-453 2005年4月 [査読有り]
The energy-transfer dynamics from peripheries to cores was investigated in two series of light-harvesting small dendrimers. In a star-shaped stilbenoid phthalocyanine having π-conjugated peripheries, a highly efficient and rapid energy transfer oc...
K. Kanemoto, M. Shishido, T. Sudo, I. Akai, H. Hashimoto, T. Karasawa
Chemical Physics Letters 402(4月6日) 549-553 2005年2月 [査読有り]
We have investigated the photoluminescence (PL) characteristics of poly(3-octylthiophene) (P3OT) diluted in a solid matrix of polypropylene (PP). Using time-resolved PL spectroscopy, we have identified a continuous increase in PL quantum efficienc...
Journal of Luminescence 108(1月4日) 11-14 2004年6月 [査読有り]
Heat generation caused by nonradiative relaxation processes in tris-8-hydroxyquinoline aluminum (Alq 3 ) was measured at 2 K by using a photocalorimetric (PC) detecting system. At lower temperatures, the photoluminescence (PL) quantum yield is muc...
H. Xie, M. Tougezaka, S. Oishi, I. Kinoshita, K, Kanemoto, I. Akai, T. Karasawa
Journal of Luminescence 108(1月4日) 91-95 2004年6月 [査読有り]
Three kinds of luminescent crystals, copper(I) cluster compounds with different ligand configurations (hexanuclear methylpyridinethiolato-copper(I): [Cu 6 (n L -mpyt) 6 ]; n L being the ligand configuration), have been investigated by observing th...
V. F. Agekyan, Yu. A. Stepanov, I. Akai, T. Karasava, L. E. Vorob'ev, D. A. Firsov, A. E. Zhukov, V. M. Ustinov, A. Zeilmeyer, S. Shmidt, S. Hanna, E. Zibik
Semiconductors 38(5) 565-571 2004年5月 [査読有り]
Luminescence spectra of doped and undoped GaAs/GaAlAs and InGaAs/GaAs/GaAlAs structures containing several tens of stepped quantum wells (QW) are investigated. The emission bands related to free and bound excitons and impurity states are observed ...
A. Tanji, H. Xie, I. Akai, T. Karasawa, V. F. Aguekian
Journal of Physical Society of Japan 72(10) 2646-2655 2003年10月 [査読有り]
Dynamical processes of high-density excitons and their relaxation mechanisms in GaSe crystals have been investigated in real and momentum spaces by observing resonant luminescence spectra of the excitons in the time- and space-resolved regimes. Te...
Physics of the Solid State 45(6) 1170-1176 2003年6月 [査読有り]
Microcrystals of iodates of mercury, lead, thallium, and bismuth were grown in pores of glass and polymer matrices from solutions or through sublimation in vacuum. Images of these microcrystals embedded in matrices were obtained with an electron m...
Photoinduced high-density phase of exciton-polariton masses excited at a two-dimensional stacking fault interface in BiI 3 has been studied by observing the degenerate four-wave-mixing (DFWM) signals. It was found that the increase in the dephasin...
In Al x Ga 1-x As/AlAs quantum wire (QWR) structures, the lower lying indirect exciton (IE) photoluminescence (PL) peak shows remarkable blue-shift under intense light-excitation contrary to the higher lying direct exciton (DE) PL band with very s...
Spatial correlation of a quantum coherence of weakly interacting stacking fault excitons (SFEs) excited heavily at a two-dimensional stacking fault interface in BiI 3 has been studied by performing the degenerate four-wave-mixing (DFWM) measuremen...
Spatial evolution of heavily photo-created excitons in GaSe single crystals has been studied by observing space- and time-resolved photoluminescence. At an early stage, the free-exciton recombination band shows a blue-shift with broadening due to ...
K. Bando, I. Akai, T. Karasawa, K. Maehashi, H. Nakashima
Journal of Luminescence 94 389-392 2002年 [査読有り]
Under intense light excitation, dynamical processes on indirect and direct excitons (DEs) at high density in Al x Ga 1-x As/AlAs quantum wire (QWR) structures have been investigated. The high density effects are characterized by the spectral blue-...
International Journal of Modern Physics B 15 3825-3828 2001年12月 [査読有り]
The relaxation dynamics of photo-excited states in single crystals of Alq 3 , utilized as organic electroluminescent (EL) devices, have been investigated. The photoluminescence (PL) peak of Alq 3 changes depending on the exciting photon energy and...
Y. Shirasaka, H. Mino, T. Kawai, I. Akai, T. Karasawa
International Journal of Modern Physics B 15 3960-3964 2001年12月 [査読有り]
Spatial behavior of the stacking fault excitons (SFE's) excited heavily in a two-dimensional space at a stacking fault interface in Bil 3 has been studied. The SFE's whose center-of mass motion is confined at the interface show more efficient spa...
K. Bando, I. Akai, T. Karasawa, K. Inoue, H. Nakashima
International Journal of Modern Physics B 15 3757-3760 2001年12月 [査読有り]
High density excitation effects on excitons in Al x Ga 1-x As/AlAs (x=0.2?0.5) quantum wires (QWRs) have been investigated. In these samples, the difference between the type-I (x?0.3) and type-II (x?0.4) band structures was clearly observed in hig...
H. Mino, M. Yamamoto, T. Kawai, I. Akai, T. Karasawa
Journal of Luminescence 87/89 278-280 2000年1月 [査読有り]
Spatial and temporal behavior of excitons heavily excited in a quasi-two-dimensional space of a stacking fault interface in BiI 3 has been studied by space- and time-resolved luminescence measurements. The luminescence spectra show the peak-energy...
M. Yamamoto, H. Mino, I. Akai, T. Karasawa, V.F. Aguekian
Journal of Luminescence 87/89 275-277 2000年1月 [査読有り]
High-density effects on the exciton states in a layered GaSe single crystal have been studied by observing photo-luminescence and degenerate four-wave-mixing (DFWM) signals. The luminescence peak of the lowest exciton states shifts from lower ener...
A. Tanji, I. Akai, K. Kojima, T. Karasawa, T. Komatsu
Journal of Luminescence 87/89 516-518 2000年1月 [査読有り]
Quantum confinement effects and nonlinear luminescence of excitons in CuI microcrystallites on the substrates of poly-methyl methacrylate have been studied. Exciton transitions due to the hexagonal structure appear in the disk-shaped microcrystall...
Journal of Luminescence 76-77 109-112 1998年2月 [査読有り]
Spatial behavior of excitons at high density was studied in a specific exciton system at a quasi-two-dimensional planar defect in layered BiI 3 crystals. Space- and time-resolved resonance luminescence spectra of the exciton slate shows clear blue...
Physical Review B - Condensed Matter and Materials Physics 58 13835-13846 1998年1月 [査読有り]
We study spatial behavior of heavily excited excitons localized at a two-dimensional space of a specific stacking fault interface in a layered crystal (Formula presented) Pump-and-probe absorption and resonant luminescence spectra of the exciton s...
T. Karasawa, T. Kawai, H. Mino, I. Akai, T. Komatsu
Journal of Luminescence 72-74 876-878 1997年6月 [査読有り]
We present transport properties of excitons at high density in a quasi-two-dimensional space of a specific stacking disorder interface in layered crystal BiI 3 , observing temporal behavior and peak energy shifts in space- and time-resolved lumine...
Journal of Luminescence 70 448-467 1996年10月 [査読有り]
The optical response of excitons confined in characteristic nanostructures in layered metal tri-iodide crystals introduced by some irregular stackings from the bulk structures is reviewed. In BiI 3 a specific stacking fault takes place during crys...
T. Karasawa, I. Akai, T. Kawai, H. Kondo, H. Mino, T. Komatsu
Progress in Crystal Growth and Characterization of Materials 33(1月3日) 97-100 1996年1月 [査読有り]
Macroscopic and efficient spreading of excitons from an exciting laser spot to the outside area along a quasi two-dimensional space of a planar-defect in BiI 3 is presented by space- and time-resolved photoluminescence, and the degenerate Four-Wav...
T. Komatsu, D. Kim, T. Kobayashi, K. Watanabe, V. F. Aguekian, T. Karasawa, I. Akai, T. Iida
Surface Review and Letters 3 1127-1131 1996年1月 [査読有り]
The size effects on the exciton absorption and luminescence spectra are studied in nanostructure of BiI 3 embedded in the matrices of bulk BiI 3 and CdI 2 crystals. The quantum-confined exciton states are observed as the absorption lines of the se...
Journal of Luminescence 66/67(1月6日) 448-452 1995年12月 [査読有り]
Macroscopic exciton transport phenomena from a small area of an exciting laser spot to outside the spot along a quasi-two-dimensional planar defect in BiI 3 , are presented from space-resolved pump-probe absorption, photoluminescence, and four-wav...
Journal of Luminescence 66/67(1月6日) 443-447 1995年12月 [査読有り]
Microcrystallites and ultra-thin films of BiI 3 embedded in CdI 2 crystals were prepared by the melt-growth method and the hot wall technique. Absorption spectra and Stokes-shifted photoluminescence bands of the excitons confined in those are pres...
T. Komatsu, E. Kawahata, T. Karasawa, I. Akai, V. F. Aguekian, M. Nakayama, K. Uchida, N. Miura
Journal of Luminescence 66-67 468-472 1995年12月 [査読有り]
The magnetic field dependence of exciton photoluminescence intensity was investigated in GaAs/AlGaAs superlattice and quantum well structures for high magnetic fields up to 40 T. We discuss the observed large magnetic field effects in terms of the...
Japanese Journal of Applied Physics 34 113-115 1995年1月 [査読有り]
We report the optical nonlinear response of the confined excitons in nanostructures induced by external stress in a layered crystal BiI 3 . The absorption intensity of the confined excitons is saturated by intense laser excitation. We clarify the ...
Journal of Luminescence 60/61 816-818 1994年4月 [査読有り]
Raman absorption of the exciton and luminescence from self-trapped exciton in SbI 3 and BiI 3 have been investigated under hyrostatic pressure. The difference in the nature of intra-layer bonding between these materials brings about the difference...
Journal of Luminescence 60/61 658-660 1994年1月 [査読有り]
The high density effects of excitons excited at a two-dimensional stacking-fault plane in layered BiI 3 crystal is investigated. The blue-shift and broadening have been observed for the high density excitation. A new transition appears below the r...
H. Kurisu, T. Komatsu, T. Tanaka, I. Akai, T. Karasawa, T. Iida
Journal of Luminescence 60-61 812-815 1994年1月 [査読有り]
Raman absorption of the exciton and luminescence from self-trapped exciton in SbI 3 and BiI 3 have been investigated under hyrostatic pressure. The difference in the nature of intra-layer bonding between these materials brings about the difference...
I. Akai, H. Kondo, M. Ichida, T. Karasawa, T. Komatsu
Journal De Physique. IV : JP 3 433-436 1993年10月 [査読有り]
Saturation spectra of the excitons confined and localized at several kinds of stacking disorders in layered crystal BiI 3 are studied. The quasi-two dimensional exciton localized at the stacking fault interface does not saturate its absorption str...
Journal of Physical Society of Japan 62(12) 4516-4521 1993年1月 [査読有り]
The exciton spectra of Sn02 single crystals with the low and high concentrations of the oxygen vacancies (OV) are investigated. The series of luminescence lines adjacent to the lowest free exciton states (the excitons localized by the isolated OV ...
T. Komatsu, T. Iida, K. Murayama, M. Ichida, H. Kurisu, H. Kondo, I. Akai, T. Karasawa
Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals 218 37-42 1992年6月 [査読有り]
Absorption line series W J (J=I,II,III,…) appeared below the indirect edge in BiI 3 has been studied. The series is assigned to the excitons confined in mesoscopic domains produced by deformation faults characteristic of layered materials. Each li...
I. Akai, K. Nakajima, T. Karasawa, M. Ichida, T. Komatsu
Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals 218 25-30 1992年6月 [査読有り]
We report the picosecond time resolved spectra of the optical Stark effect on a quasi-two-dimensional exciton localized at a stacking fault plane in Bil 3 crystals. The ultrafast response of the blue-shift due to the optical Stark effect(OSE) is c...
On the exciton states localized at a two-dimensional stacking fault interface in a layered crystal BiI 3 , some nonlinear optical phenomena clearly appear reflecting large transition probability. The optical Stark shift and other high density exci...
T. Kawai, S. Shimanuki, T. Karasawa, I. Akai, T. Iida, T. Komatsu
Journal of Luminescence 48-49 1991年1月 [査読有り]
Fast and ballistic spreading of excitons excited at the stacking fault interface in BiI 3 crystals was observed in the temporal behavior of exciton luminescence with space- and time-resolved measurements. The spreading velocity reaches ?7 × 10 8 c...
We present the observation of an optical Stark effect on multiple exciton states localized at a stacking fault in layered crystal BiI3. The level anticrossings concerning the crystal ground state as well as the multiple exciton states are clearly ...
Summary form only given. The time-resolved optical Stark effect (OSE) with high spectral resolution is presented for a characteristic exciton system. In the layered crystal BiI 3 , several sharp absorption lines appear near the absorption edge. Th...
Journal of Luminescence 42(6) 357-363 1989年1月 [査読有り]
The luminescence decay processes of the three ground-state excitons localized at a stacking fault with quasi two-dimensional symmetry in layered BiI 3 crystals were investigated in the picosecond time domain. The characteristic time behaviour of t...
Journal of Physical Society of Japan 58(3) 969-977 1989年 [査読有り]
The study of exciton transfer along the stacking fault interface in BiI 3 crystals is presented by using a newly designed space-resolved spectroscopy method. The resonant luminescence lines of the excitons with exact zero Stokes shift were observ...
Journal of Physical Society of Japan 58(2) 718-725 1989年 [査読有り]
We have studied photocalorimetric spectra (PCS) of characteristic exciton transitions in Bil 3 crystals. Our PCS measuring system has the sensitivity of less than 10 -12 J - for the detection of photo-thermal heating after photo-excitation. The...
Journal of Luminescence 40/41 431-432 1988年1月 [査読有り]
The direct observation of propagation of the excitons confined at the stacking fault interface in layered BiI 3 is presented by using a newly designed space-resolved spectroscopy. Extraordinary large diffusion constants of more than 10 5 cm 2 /sec...
physica status solidi (b) 150(2) 635-639 1988年1月 [査読有り]
The optical Stark effect of an exciton system localized at a stacking fault (stacking fault excitons, SFE) in BiI 3 crystals is presented. The SFE states show three very sharp absorption lines called R, S, and T. The excitation laser frequency de...
We have investigated coherent phonons in trans-stilbene, which is one of the light-harvesting (LH) antenna component molecules of LH-dendrimers. In the LH-dendrimers, low frequency vibrational modes in the LH-antenna subunits play an important rol...
To obtain further understanding of the energy transfer in light harvesting (LH) dendrimer, we studied optical spectra of LH antenna component molecules and examined the electronic structure of these molcules. In 1,3,5-triphenylbenzene and 1,3-diph...
We studied μPL spectra in a Lz-gradient quantum well structure. In the Lz-gradient QW, the thickness of the QW changes monotonously along the Y-axis of the sample, and the peak shifts of excitonic luminescence are observed depending on Lz. In addi...
At room temperature, a rapid energy transfer (ET) occurs efficiently under the selective excitation of light-harvesting (LH) antennas in phenylene-based dendrimers (PhDGn;n=1,2). However, the ET quantum efficiency degrades obviously at temperature...
From analyses of molecular vibrations, we have studied rapid energy transfer (ET) process in a series of star-shaped stilbenoid phthalocyanine (SSSnPc;n=1,2) dendrimers having π-conjugated light harvesting (LH) antennas. In SSSnPc, the aromatic ri...
Bayesian estimation of excitonic absorption spectra with the Metropolis algorithm
K. Iwamitsu, S. Aihara, M. Okada and I. Akai
International Meeting on "High-Dimensional Data Driven Science" (HD3-2015) 2015年12月14日
Long continuing coherent phonon in a bismuth thin-film
M. Hamamoto, K. Iwamitsu, I. Akai
International Symposium on Advanced Materials Having Multi-Degrees-of-Freedom -- Optical properties, Structural Analyses, Imaging and Informatics of Materials -- (ISAMMDoF2015) 2015年11月2日
Optimal Growth Condition of Layered Semiconductor BiI3 Grown by Hot-Wall Method
R. Sakamoto, K. Iwamitsu, S. Aihara, F. Ichikawa, T. Shimamoto, I. Akai
International Symposium on Advanced Materials Having Multi-Degrees-of-Freedom -- Optical properties, Structural Analyses, Imaging and Informatics of Materials -- (ISAMMDoF2015) 2015年11月2日
Photoluminescence spectra in Cu2O thin crystals and thier polarization dependences
K. Gunji, S. Aihara, F. Ichikawa, I. Akai
International Symposium on Advanced Materials Having Multi-Degrees-of-Freedom -- Optical properties, Structural Analyses, Imaging and Informatics of Materials -- (ISAMMDoF2015) 2015年11月2日
Bayesian deconvolution of photoluminescence spectra of yellow 1S excitons in Cu2O thin films sandwiched by MgO plates
S. Aihara, K. Gunji, K. Iwamitsu, M. Okada, I. Akai
International Symposium on Advanced Materials Having Multi-Degrees-of-Freedom -- Optical properties, Structural Analyses, Imaging and Informatics of Materials -- (ISAMMDoF2015) 2015年11月2日
Bayesian Estimation of Excitonic Absorption Spectra
K. Iwamitsu, S. Aihara, M. Okada, I. Akai
International Symposium on Advanced Materials Having Multi-Degrees-of-Freedom -- Optical properties, Structural Analyses, Imaging and Informatics of Materials -- (ISAMMDoF2015) 2015年11月2日
Excitonic Transitions in Thin Films of Layered Semiconductor BiI3 Grown by a Hot-Wall Technique
R. Sakamoto, T. Ueda, K. Iwamitsu, F. Ichikawa, K. Watanabe, T. Shimamoto, and I. Akai
17th International Conference on Modulated Semiconductor Structures (Joint Conference EP2DS-21/MSS-17) 2015年7月26日
Trapping potential formation for the yellow 1S excitons in Cu2O thin films sandwiched by MgO plates
S. Aihara K. Gunji, A. Ota, K. Iwamitsu, F. Ichikawa, H. Isobe, T. Shimamoto, I. Akai
17th International Conference on Modulated Semiconductor Structures (Joint Conference EP2DS-21/MSS-17) 2015年7月26日
29pPSA-47 Hot Wall法で成膜したBiI_3薄膜のX線回折と励起子スペクトル(29pPSA 領域5ポスターセッション(放射光,光電子分光,発光,非線形,フォトニック結晶),領域5(光物性))
上田 智博, 相原 慎吾, 岩満一功, 市川 聡夫, 島本 知茂, 赤井 一郎
日本物理学会講演概要集 2014年3月5日
Diffusion of high density excitons in Lz-gradient quantum well[招待有り]
赤井 一郎
The Fifth Meeting of Research Consortium on High-pressure Research and The Kumamoto International Symposium on Recent Advancements of Physics and Mineralogy VI 2014年1月20日
MgO基板に挟まれたCu2O薄膜の励起子発光スペクトル
日本物理学会「第69回年次大会」(東海大学 湘南キャンパス) 2014年
MgO基板に挟まれたCu2O薄膜における波長変調吸収スペクトルの格子歪効果III
日本物理学会「第69回年次大会」(東海大学 湘南キャンパス) 2014年
Hot Wall法で成膜したBiI3薄膜のX線回折と励起子スペクトル
日本物理学会「第69回年次大会」(東海大学 湘南キャンパス) 2014年
Photoluminescence spectra and their temperature dependence of yellow-excitons in Cu2O thin films re-crystallized epitaxially between paired MgO plates
nd International Symposium on Kumamoto Synchrotron Radiation (ISKSR2): Young Sciensits’Day 2014年
Two-Dimensional Compressive Stress Effect in Cu2O Thin Films Sandwiched by MgO Substrates
nd International Symposium on Kumamoto Synchrotron Radiation (ISKSR2): Young Sciensits’Day 2014年
Photoluminescence spectra and their temperature dependence of yellow-excitons in Cu2O thin films re-crystalized epitaxially between paired MgO plates
The International Conference of Luminescence (ICL2014) 2014年
Photoluminescence spectra and their temperature dependence of CdTe multi-quantum wells sandwiched by ultrathin MnTe layers
The International Conference of Luminescence (ICL2014) 2014年