Publication list of

peer reviewed papers

 
 

Publication list


I. Umezu, S. Okubo and A. Sugimura

Effect of Non-equilibrium Pulsed Ejection of Si Species into Background Gas on the Formation of Si Nanocrystallite and Nanocrystal-film

Mater. Res. Soc. Symp. Proc.1305 (2011)


I. Umezu, S. Yamamoto and A. Sugimura

Emission induced by collision of two plumes during pulsed laser ablation

Applied Physics A 101(2010) 133-136


I. Umezu, Y. Nakayama and A. Sugimura

Formation of core-shell structured silicon nanoparticles during pulsed laser Ablation

J. Appl. Phys. 107 (2010) 094318


K. Tai, W. Lü, I. Umezu and A. Sugimura

Inter-Dot Distance Dependence of Photoluminescence Properties in CdSe Quantum Dot Systems

Appl. Phys. Express 3 (2010) 035202


B. P. Bob, A. Kohno, S. Charnvanichborikarn, J. M. Warrender, I. Umezu, M. Tabbal, J. S. Williams and M. J. Aziz

Fabrication and Sub-Bandgap Optical Properties of Silicon Supersaturated with Chalcogens by Ion Implantation and Pulsed Laser Melting

J.Appl. Phys. 107(2010) 123506


T. Yoshida, H. Toyoyama, I. Umezu and A. Sugimura

Synthesis of Ni-doped InTaO4 nanocrystallites by reactive pulsed laser ablation for application to visible-light-operating photocatalysts

Appl. Surf. Sci. 255 (2009 ) 9634-9637


W. Lü, Y. Tokuhiro, I. Umezu, A. Sugimura and Y. Nagasaki

Trap state emission of water-soluble  CdS nanocrystals

phys. stat. sol. (c)  6(2009) 346-349


T. Yoshida, H. Toyoyama, I. Umezu and A. Sugimura

InTaO4-based nanostructures synthesized by reactive pulsed laser ablation

Applied Physics A 93 (2008) 961-966


I. Umezu, T. Makino, M. Inada, K. Matsumoto and A. Sugimura

Oxidation processes of surface hydrogenated silicon nanocrystallites prepared by pulsed laser ablation and their effects on the photoluminescence wavelength

J. Appl. Phys. 103 (2008) 024305


A. Sugimura, M. Gibo, M. Inada, T. Saitoh and I. Umezu

Collective Transport in Silicon Nanocrystal Assembly Prepared by Laser Ablation Method

Mater. Res. Soc. Symp. Proc. Vol. 1145 (2008) MM04-02-


I. Umezu, M. Takata and A. Sugimura.
Surface hydrogenation of silicon nanocrystallites during pulsed laser ablation of silicon target in hydrogen background gas.
J. Appl. Phys 103, (2008)114309.

I. Umezu, I. Kondo and A. Sugimura.
Formation of surface stabilized Si nanocrystal by pulsed laser ablation in hydrogen gas.
Applied Physics A (2008)

I. Umezu, T. Makino, M. Inada, K. Matsumoto and A. Sugimura.
Oxidation processes of surface hydrogenated silicon nanocrystallites prepared by pulsed laser ablation and their effects on the photoluminescence wavelength.
J. Appl. Phys. 103, (2008)024305 1-8.

T. Yoshida, H. Toyoyama, I. Umezu and A. Sugimura.
InTaO4-based nanostructures synthesized by reactive pulsed laser ablation.
Applied Physics A 92, (2008)

W. L I. Umezu and A. Sugimura.
Evolution of Energy Transfer Process between Quantum Dots of Two Different Sizes during the Evaporation of Solvent.
Jpn. J. Appl. Phys., Part 1 47, (2008)6592.

A. Sugimura, M. Koyama, M. Inada, T. Yoshida and I. Umezu.
Mechanism of Electron-Hole Pair Generation and Light Emission for Electro-Luminescence Devices with Silicon Nano-Crystals Prepared by Laser Ablation Method.
Proceedings of 28th international conference on the physics of semiconductors (AIP Conf. Proc.) 893, (2007)1433.

I. Umezu, H. Minami, H. Senoo and A. Sugimura.
Synthesis of photoluminescenct colloidal silicon nanoparticles
by pulsed laser ablation in liquids.
J. Phys.: Conf. Ser. 59, (2007)392-395.

M. Takata, I. Umezu and A. Sugimura.
Plume analysis during pulsed laser ablation of silicon in hydrogen gas.
J. Phys.: Conf. Ser. 59, (2007)575-578.

I. Umezu, M. Inada, T. Makino and A. Sugimura.
Fractal growth of silicon nanocrystallites during pulsed laser ablation.
Proceedings of 28th international conference on the physics of semiconductors (AIP Conf. Proc.) 893, (2007)43.

I. Umezu, A. Sugimura, M. Inada, T. Makino, K. Matsumoto and M. Takata.
Formation of nanoscale fine-structured silicon by pulsed laser ablation in hydrogen background gas.
Phys. Rev. B 76, (2007)045328 1-10.

I. Umezu, M. Koyama, T. Yoshida and A. Sugimura.
Effects of surface oxidation on optical absorption of sillicon nanocrystallites.
Proceedings of 28th international conference on the physics of semiconductors (AIP Conf. Proc.) 893, (2007)1433.

M. Takiya, I. Umezu, M. Yaga and M. Han.
Nanoparticle formation in the expansion process of a laser ablated plume.
J. Phys.: Conf. Ser. 59, (2007)445-448.

W. L Y. Tokuhiro, I. Umezu, A. Sugimura and Y. Nagasaki.
Resonance energy transfer based on shallow and deep energy levels of biotin-polyethylene glycol/polyamine stabilized CdS quantum dots.
APPL. PHYS. LETT. 89, (2006)143901-1-143901-2.

I. Umezu, T. Kimura and A. Sugimura.
Effects of surface adsorption on the photoluminescence wavelength of silicon nanocrystal.
Physica B 376-377, (2006)853-856.

I. UMEZU, M. Inada, T. Makino and A. Sugimura.
Preparation of surface controlled silicon nanocrystallites by pulsed laser ablation.
AIP conference proceedings (The Proceedings of the 27th International Conference on the Physics of Semiconductors) 772, (2005)861-862.

I. UMEZU, M. Koyama, T. Hasegawa, Kimihisa Matsumoto, M. Inada and A. Sugimura.
Correlation between PL emission band and growth of oxide layer on surface of silicon nanocrystallites.
AIP conference proceedings (The Proceedings of the 27th International Conference on the Physics of Semiconductors) 772, (2005)855-856.

K. Matsumoto, M. Inada, I. Umezu and A. Sugimura.
A correlation between natural oxidation process and PL properties
of hydrogenated Si nanocrystallites prepared by pulsed laser
ablation.
Jpn. J. Appl. Phys. 44, (2005)8742-8746.

T. Makino, M. Inada, I. Umezu and A. Sugimura.
Structural and optical properties of surface-hydrogenated silicon nanocrystallites prepared by reactive pulsed laser ablation.
J. Phys. D 38, (2005)3507-3511.

I. UMEZU, T. Makino, M. Takata, M. Inada and A. Sugimura.
Correlation between electronic structure and chemical bond on the surface of hydrogenated silicon nanocrystallites.
AIP conference proceedings (The Proceedings of the 27th International Conference on the Physics of Semiconductors) 772, (2005)691-692.

M. Ichida, I. Umezu, H. Kataura, M. Kimura, S. Suzuki, Y. Achiba and H. Ando.
Temperature dependence of time-resolved luminescence
spectra for 1D excitons in single-walled carbon nanotubes
in micelles.
Journal of Luminescence 112, (2005)287-290.

H. Kobori, T. Nanao, S. Kawaguchi, I. Umezu and A. Sugimura.
Considerable enhancement of PL intensity for free exciton in ZnO ultra-fine-particles and oscillatory green band emergence in PL spectrum for Cu-doped ZnO ultra-fine particles with heat treatment.
The Proceedings of the 27th International Conference on the Physics of Semiconductors (2005)867-868.

M. Inada, I. Umezu, S. Tanaka, S. Mashiko and A. Sugimura.
Formation of Hydrogen-passivated silicon Nanochains by Pulsed laser Ablation without Thermal Annealing.
Mater. Res. Soc. Symp. Proc. 832, (2005)F7.24.1-F7.24.5.

M. Inada, I. Umezu, P. O. Vaccaro, S. Yamada and A. Sugimura.
Inter-dot electron transport in coupled InAs quantum dots under magnetic field.
Semicond. Sci. Technol. 19, (2004)S54-S55.

T. Makino, M. Inada1, K. Yoshida, I. Umezu and A. Sugimura1.
Structural and optical properties of silicon nanoparticles prepared by
pulsed laser ablation in hydrogen background gas.
Applied Physics A 79, (2004)1391.

I. Umezu, K. Matsumoto, M. Inada, T. Makino and A. Sugimura.
Correlation between surface oxide and photoluminescence properties of Si nanoparticles prepared by pulsed laser ablation.
Applied Physics A 79, (2004)1545-1547.

I. Umezu, R. Koizumi, A. Sugimoto, M. Inada, T. Makino, A. Sugimura, Y. Sunaga, T. Ishii and Y. Nagasaki.
Recombination process of CdS quantum dot covered by novel Polymer Chains.
Physica E 21, (2004)1102-1105.

M. Inada, I. Umezu, P. O. Vaccaro, S. Yamada and A. Sugimura.
Optical and transport studies in coupled InAs quantum dots embedded in GaAs.
Physica E 21, (2004)317-321.

T. Makino, N. Suzuki, Y. Yamada, T. Yoshida, I. Umezu and A. Sugimura.
Mechanisms of Visible Photoluminescence from Size-Controlled Silicon Nanoparticles.
Mat. Res. Soc. Symp. Proc. 737, (2003)265-270.

I. Umezu, M. Inada, H. Nakagawa, K. Matsumoto and A. Sugimura. Correlation between structure and nonradiative recombination process
in silicon nanocrystallites (Institute of Physics Publishing, Bristol (UK)and Philadelphia (USA), 2003) Institute of Physics Conference Series Number 171 D173, 1-5.

I. Umezu, K.Mandai1, R. Koizumi1, M. Inada, A. Sugimura, Y. Sunaga, T. Ishii and Y. Nagasaki. Optical properties of CdS quantum dot covered by novel polymer chains (Institute of Physics Publishing, Bristol (UK)and Philadelphia (USA), 2003) Institute of Physics Conference Series Number 171 H202, 1-5.

I. Umezu, M. Inada, K. Kohno, T. Yamaguchi, T. Makino and A. Sugimura.
Reaction between nitrogen gas and silicon species during
pulsed laser ablation.
J. Vac. Sci. Technol. A 21, (2003)1680-1682.

I. Umezu, K. Mandai, R. Koizumi, M. Inada, A. Sugimura, Y. Sunaga, T. Ishii and Y. Nagasaki.
Optical Properties of CdS Nanocrystal Covered by Polymer Chains on the Surface.
MicroElectronic Engineering 66, (2003)53-58.

M. Inada, S. Sato, I. Umezu, P. O. Vaccaro, S. Yamada and A. Sugimura. Observation of inter-dot electron transport via spin-split states in InAs quantum dots (Institute of Physics Publishing, Bristol (UK)and Philadelphia (USA), 2003) Institute of Physics Conference Series Number 171 H188,1-5.

M. Inada, I. Umezu and A. Sugimura.
Effect of gas pressure on reactive pulsed laser ablation of a silicon target.
J. Vac. Sci. Technol. A 21, (2003)84-86.

M. Inada, H. Nakagawa, I. Umezu and A. Sugimura.
Effects of hydrogenation on photoluminescence of Si nanoparticles formed by pulsed laser ablation.
Materials Science & Engineering B 101, (2003)pp. 283-285.

I. Umezu, K. Kohno, T. Yamaguchi, A. Sugimura and M. Inada.
Deposition of silicon nitride films by pulsed laser ablation of Si target in nitrogen gas.
J. Vac. Sci. and technol. A 20, (2002)30-32.

M. Inada, H. Nakagawa, I. Umezu and A. Sugimura.
Effects of hydrogen on Si nanoparticles formed by pulsed laser ablation.
Applied surface science 197-198, (2002)666-669.

I. Umezu, K.-i. Yoshida, N. Sakamoto, T. Murota, Y. Takashima, M. Inada and A. Sugimura.
Photoluminescence Properties of Amorphous Silicon-based Oxygen and Hydrogen Alloys.
J.Appl. Phys. 91, (2002)2009-2014.

I. Umezu, T. Yamaguchi, K. Kohno, M. Inada and A. Sugimura.
Preparation of SiNx film by pulsed laser ablation in nitrogen gas ambient.
Appl. Surf. Sci. 197-198C, (2002)314-316.

I. Umezu, Takashi Yoshida, K. Matsumoto, A. Sugimura and M. Inada.
Nanoscale anodization of an amorphous silicon surface with an atomic force microscope.
Appl. Phys. Lett. 81, (2002)1492-1493.

I. Umezu, K. Kohno, K. Aoki, Y. Kohama, A. Sugimura and M. Inada.
Effects of Argon and hydrogen plasmas on the surface of silicon.
Vacuum 66/3-4, (2002)453-456.

K. Yoshida, I. Umezu, N. Sakamoto, M. Inada and A. Sugimura.
Effect of Structure on Radiative Recombination Process in Amorphous Silicon Suboxide Prepared by RF Sputtering.
Journal of applied physics 92, (2002)5936-5941.

I. Umezu, T. Yoshida, K. Matsumoto, M. Inada and A. Sugimura.
Nano-oxidation of an amorphous silicon surface with an atomic force microscope.
J. Noncryst. solids 299-302, (2002)1090-1094.

I. Umezu, K. Yoshida, M. Inada and A. Sugimura.
Photoluminescence from Nanoscale Si in a-SiOx matrix.
Mat. Res. Soc Symp. Proc. 638, (2001)F5.19.1-F5.19.6.

I. Umezu, G. Yamazaki, T. Yamaguchi, A. Sugimura, T. Makino, Y. Yamada, N. Suzuki and T. Yoshida.
Effects of annealing on luminescence properties of Si nanocrystallites prepared by pulsed laser ablation in inert gas.
Materials Science & Engineering C Vol 15/1-2, (2001)129-131.

M. Inada, K. Ohnishi, I. Umezu, P. O. Vaccaro and A. Sugimura.
Many body effect in photo-conductivity in InAs/GaAs self assembled quantum dots.
Mat. Res. Soc. Symp. Proc. 642, (2001)J3.3.2-J3.3.6.

A. Sugimura, K. Ohnishi, I. Tadamasa and I. Umezu.
Effects of inter-dot electronic coupling on laser gain in InAs/GaAs quantum dot ensemble.
Mat.Res.Soc.Symp.Proc., 642, (2001)J5.5.1-J5.5.6.

M. Inada, T. Fujishima, I. Umezu, A. Sugimura and S. Yamada.
Conduction-type control of Ge films grown on (NH4)2S-treated GaAs by molecular beam epitaxy.
Journal of Crystal Growth 227-228, (2001)791-795.

I. Umezu, T. Murota, M. Kawata, Y. Takashima, K.-i. Yoshida, M. Inada and A. Sugimura.
correlation between Photoluminescence Intensity and Micro Structure in Amorphous Silicon Films Prepared by Reactive RF Sputtering.
Jpn. J. Appl. Phys. 39 Part2, (2000)L844-L846.

I. Umezu, K. Yoshida, A. Sugimura, T. Inokuma, S. Hasegawa, Y. Wakayama, Y. Yamada and T. Yoshida.
A comparative study of photoluminescence properties of a-SiOx:H film and silicon nanocrystallites.
Journal of Non-Crystalline Solids 266-9, (2000)1029-1032.

K. Ohnishi, M. Inada, I. Umezu, A. Sugimura and P. O. Vaccaro.
Lateral photo-conductance via in-plane inter-dot tunneling in self-assembled InAs/GaAs quantum dot ensemble.
Proc.25th Int. Conf. Phys. Semicond. (2000)1063-1064.

A. Sugimura, K. Ohnishi, I. Umezu and P. O. Vaccaro.
Optical Properties of Self-assembled InAs Quantum Dots Grown on GaAs(211)A Substrates.
Thin film solids 380, (2000)97-100.

K. Oyoshi, N. Sumi, I. Umezu, R. Souda, A. Yamazaki, H. Haneda and T. Mitsuhashi.
Structure, optical absorption and electronic states of Zn+ ion implanted and subsequently annealed sol-gel anatase TiO2 films.
Nuclear Instruments and Methods in Physics Research B 168/2, (2000)221-228.

H. Kataura, Y. Kumazawa, N. Kojima, Y. Maniwa, I. Umezu, S. Masubuchi, S. Kazama, Y. Ohtsuka, S. Suzuki and Y. Achiba.
Resonance Raman Scattering of Br2 Doped Single-Walled Carbon Nanotube Bundles.
Mol. Cryst. and Liq. Cryst. 340, (2000)757-762.

K. Oyoshi, N. Sumi, I. Umezu, A. Yamazaki, H. Haneda and T. Mitsuhashi
Structure and optical absorption of Cr+, Fe+ and Zn+ Ion Implanted and Subequently Annealed Sol-gel anatase TiO2 Films
The 18 th Symposium on Materials Science and Engineering Research Center of Ion Beam Technology, Tokyo, Japan, 1999

H. Kataura, Y. Kumazawa, N. Kojima, Y. Maniwa, I. Umezu, S. Masubuchi, S. Kazama, X. Zhao, Y. Ando, Y. Ohtsuka, S. Suzuki and Y. Achiba
Optical absorption and resonance Raman scattering of carbon nanotubes
Proceedings of international winter schools on electronic properties of novel materials 1999, Kirchberg, Tirol, Austria, 1999(American Institute of Physics)

H. Kataura, Y. Kumazawa, Y. Maniwa, I. Umezu, S. Suzuki, Y. Ohtsuka and Y. Achiba.
Optical Properties of Single-Wall Carbon Nanotubes.
Synthetic Materials 103, (1999)2555-2558.

S. Sakata, P. O.Vaccaro, S. Yamaoka, I. Umezu and A. Sugimura
Selective oxidation of vanadium thin film surfaces using an atomicforce microscope
Optoelectronic and Microelectronic Materials Devices, 1998. Proceedings. 1998 Conference on, Perth, WA, Australia, 1999

I. Umezu, K. Shibata, S. Yamaguchi, A. Sugimura, Y. Yamada and T. Yoshida.
Effects of thermal processes on photoluminescence of Si nanocrystallites prepared by pulsed laser ablation.
J. Appl. Phys. 84, (1998)6448-6450.

K. Maeda and I. Umezu.
Defect Formation Mechanism during PECVD of Undoped a-Si:H.
Journal of Non-Crystalline Solids 227-230, (1998)43-47.

I. Umezu, T. Kuwamura, K. Kitamura, T. Tsuchida and K. Maeda.
Effect of plasma treatment on the density of defects at an amorphous Si:H-insulator interface.
Journal of Applied Physics 84, (1998)1371-1377.

P. O. Vaccaro, S. Sakata, S. Yamaoka, I. Umezu and A. Sugimura.
Nano-oxidation of vanadium thin films using atomic force microscopy.
Journal of materials science letters 17, (1998)1941-1943.

I. Umezu, T. Tsuchida and K. Maeda.
A study of interface state density between a-Si:H and insulating layer in terms of plasma surface reaction.
Journal of Non-Crystalline Solids 227-230, (1998)1235-1239.

A. Sugimura, P. O. Vaccaro, I. Umezu and K. Hara
IN-PLANE ELECTRONIC COUPLING IN SELF_ORGANIZED QUANTUM DOT ENSEMBLE
The 24 th International conference on the physics of semiconductors, 1998

I. Umezu, T. Murota, M. Kawata, K. Yoshida and A. Sugimura
EFFICIENT PHOTOLUMINESCENCE FROM a-SI:H FILM PREPARED BY REACTIVE RF SPUTTERING
The 24 th International conference on the physics of semiconductors, 1998

I. Umezu, K. Shibata, S. Yamaguchi, H. Sato, A. Sugimura, Y. Yamada and T. Yoshida
Effects of thermal Processing on Photoluminescence of Si Nanocrystallites Prepared by Pulsed Laser Ablation
Proceedings of ECS 98-19, Quantum Confinement V:
Nanostructures, Boston, 1998

I. Umezu, S. Yamaguchi, K. Shibata, A. Sugimura, Y. Yamada and T. Yoshida.
Temperature-dependent photoluminescence of Si nanocrystallites prepared by inert gas
ambient pulsed laser ablation.
Mat. Res. Soc. Symp. Proc 486, (1998)219-223.

K. Maeda, I. Umezu and H.Ishizuka.
Defect formation during deposition of undoped a-Si:H by rf glow discharge.
Phys. Rev. B 55, (1997)4323-4331.

K. Maeda and I. Umezu.
Defect Formation mechanism during PECVD of a-Si:H.
Mat.Res.Soc.Symp.Proc,
Amorphous Silicon Technology 1996 469, (1997)573-578.

Y. Yamada, T. Orii, I. Umezu, S. Takeyama and T. Yoshida.
Optical Properties of Silicon Nanocrystallites Prepared by Excimer Laser Ablation in Inert Gas.
Jpn. J. Appl. Phys. 35, (1996)1361-1365.

T. Yoshida, Y. Yamada, S. Takeyama, T. Orii, I. Umezu and Y. Makita
Optical properties of silicon nanocrystallites prepared by pulsed laser ablation in inert gas ambient
Laser Processing of Materials and Industrial Applications, Beijing, China, 1996

K. Maeda and I. Umezu
Defect formation during deposition of undoped a-Si:H by PECVD
Materials Research Society, San Francisco, 1996

I. Umezu, K. Kitamura and K. Maeda.
Investigation of Interface state density between a-Si:H and insulating layers by ESR and photothermal deflection spectroscopy.
J. Non-Cryst. Solids 198-200, (1996)778-781.

K. Maeda, A. Kuroe and I. Umezu
Surface reaction mechanism during deposition of a-Si:H by PECVD
Materials Reserch Society, San Francisco, 1995

K. Maeda, N. Sakamoto and I. Umezu.
A comparative study on structural and electronic properties of PECVD a-SiOx with a-SiNx.
Journal of Non-Crystalline Solids 187, (1995)287-290.

I. Umezu, T. Kuwamura and K. Maeda
Effect of Plasma Damage on Interface State Density Between a-Si:H and Insulating Films
Materials Reserch Society, San Francisco, 1995(Pittsburg)

K. Maeda, A. Kuroe and I. Umezu.
Mechanism of surface reaction in the deposition process of a-Si:H by rf glow discharge.
Physical Review B 51, (1995)10635-10645.

I. Umezu, K. Miyamoto, N. Sakamoto and K. Maeda.
Optical Bond-gap and Tauc-gap in a-SiOx:H and a-SiNx:H Films.
Japanese Journal of Applied Physics 34, (1995)1753-1758.

K. Maeda, A. Kuroe and I. Umezu.
Dehydrogenation reaction on growing surface of a-Si:H by PECVD.
Digest of technical papers AM-LCD94 (1994)176-179.

I. Umezu and K. Maeda.
Analysis of Joule Heat in a-Si:H Film by Photo-thermal
Deflection Spectroscopy.
Japanese Journal of Applied Physics 33, (1994)5647-5651.

K. Maeda, W. Chiyoda, I. Umezu and A. Kuroe.
Depletion layer width in undoped a-Si:H Schottky barrier rerated by reverse bias photocurrent.
Journal of Applied Physics 75, (1994)3522-3529.

I. Umezu, M. Daigo and K. Maeda.
Investigation of Surface Passivation Effect of a-SiNx:H on a-Si:H by Photothermal Deflection Spectroscopy.
Japanese Journal of Applied Physics 33, (1994)L873-875.

K. Maeda, T. Jinnai and I. Umezu.
Interface State Density of SiNx:H/c-Si MIS Structure.
Journal of Non-Crystalline Solids 164-166, (1993)849-852.

K. Maeda and I. Umezu.
Atomic microstructure and electronic properties of a-SiNx:H deposited by radio frequency glow discharge.
Journal of Applied Physics 70, (1991)2745-2754.

K. Maeda and I. Umezu.
Atomic microstructure and electronic properties of a-SiNx:H deposited by PECVD.
Journal of Non-Crystalline Solids 137&138, (1991)883-886.

I. Umezu and K. Maeda.
Structure of Amorphous SiNx:H Studied by Photoemission and Infrared Absorption.
Japanese Journal of Applied Physics 30, (1991)2547-2552.

K. Maeda, I. Umezu and A. Kawaguchi.
Investigation of SiNx/Si interface by capacitance method.
Journal of Applied Physics 59, (1991)2421-2423.

K. Maeda, I. Umezu, H. Ikoma and T. Yoshimura.
Nonideal J-V characteristics and interface states of an a-Si:H Schottky barrier.
Journal of Applied Physics 68, (1990)2858-2867.

K. Maeda, I. Umezu, H. Ikoma and T. Yoshimura
Theory of Non-Ideal Characteristics of Schottky Barriers and Its Application to a-Si:H Schottky Barriers
Extended Abstracts of the 22nd Conferences on Solid State Device and Materials, 1990

T. Arai, H. Fujimura, I. Umezu, T. Ogawa and A. Fujii.
Effect of Size Confinement on the Electronic States of CdS Cluster in a Germanium Oxide Matrix.
Japanese Journal of Applied Physics 28, (1989)484-489.

I. Umezu, T. Ogawa and T. Arai.
Temperature Dependence of Photoacoustic and Photoluminescence Signals for CdSxSe1-x Microcrystals.
Japanese Journal of Applied Physics 28, (1989)477-483.

C. Sugiura, M. Kitamura, S. Muramatsu, S. Shoji, S. Kojima, Y. Tada, I. Umezu and T. Arai.
Sulfur-K X-Ray Spectra and Electronic Structure of a Semiconductor Ag2S.
Japanese Journal of Applied Physics 27, (1988)1216-1219.

I. Umezu, T. Ogawa and T. Arai.
Estimation of Non-radiative Transition Rate in Tetracen-Doped Anthracene by Photoacoustic Spectroscopy.
Japanese Journal of Applied Physics 27, (1988)835-838.

Photo of Pulsed Laser ablation system