Associate Professor Somchai Ratanathammaphan, D. Eng.
รศ. ดร.สมชัย รัตนธรรมพันธ์
Education
- D.Eng Electrical Engineering, Chulalongkorn University
- M.Eng. Electrical Engineering, Chulalongkorn University
- B.Eng. Electrical Engineering, Chulalongkorn University
Email: Somchai.R@chula.ac.th
Research Interest
- Integrated optics
- Semiconductor lasers
- III-V compound technology
- Printed electronics
- Application of nanoparticles on electronic manufacturing
Research Cluster
1.
Zon,; Korkerdsantisuk, T; Sangpho, A; Thainoi, S; Prasatsap, U; Kiravittaya, S; Thornyanadacha, N; Tandaechanurat, A; Nuntawong, N; Sopitpan, S; Yordsri, V; Thanachayanont, C; Kanjanachuchai, S; Ratanathammaphan, S; Panyakeow, S
Investigation of hybrid InSb and GaSb quantum nanostructures Journal Article
In: Microelectronic Engineering, vol. 237, 2021, ISSN: 01679317, (cited By 0).
@article{Zon2021,
title = {Investigation of hybrid InSb and GaSb quantum nanostructures},
author = {Zon and T Korkerdsantisuk and A Sangpho and S Thainoi and U Prasatsap and S Kiravittaya and N Thornyanadacha and A Tandaechanurat and N Nuntawong and S Sopitpan and V Yordsri and C Thanachayanont and S Kanjanachuchai and S Ratanathammaphan and S Panyakeow},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85097898709&doi=10.1016%2fj.mee.2020.111494&partnerID=40&md5=849c53b696aaff87b8aa000f5a7cbdb3},
doi = {10.1016/j.mee.2020.111494},
issn = {01679317},
year = {2021},
date = {2021-01-01},
journal = {Microelectronic Engineering},
volume = {237},
publisher = {Elsevier B.V.},
abstract = {Hybrid InSb and GaSb nanostructures (NSs) with different repeated cycles; one, two and four, are inserted in double AlGaAs/GaAs heterostructures by molecular beam epitaxy in Stranski-Krastanov mode. Their morphologies and cross-sectional structure are inspected by atomic force microscopy and transmission electron microscopy. Raman spectroscopy reveals the effect of strains produced by the presence of InSb and GaSb NSs. Optical properties of hybrid InSb and GaSb NSs are investigated by power- and temperature-dependent photoluminescence (PL) spectroscopy. Broad and strong PL emission of hybrid NSs are observed from 20 K to room temperature. The Ohmic contacts are performed by gold alloys metallization and gold bonding on the p-n heterojunction devices for electrical current density-voltage characterization of the devices. Photovoltaic effect of hybrid quantum NS-devices with different NS-cycles are tested and recorded under various illumination intensities. Spectral response at long wavelength in infrared region beyond 1 μm originated from the presence of hybrid NSs is detected. © 2020 Elsevier B.V.},
note = {cited By 0},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Hybrid InSb and GaSb nanostructures (NSs) with different repeated cycles; one, two and four, are inserted in double AlGaAs/GaAs heterostructures by molecular beam epitaxy in Stranski-Krastanov mode. Their morphologies and cross-sectional structure are inspected by atomic force microscopy and transmission electron microscopy. Raman spectroscopy reveals the effect of strains produced by the presence of InSb and GaSb NSs. Optical properties of hybrid InSb and GaSb NSs are investigated by power- and temperature-dependent photoluminescence (PL) spectroscopy. Broad and strong PL emission of hybrid NSs are observed from 20 K to room temperature. The Ohmic contacts are performed by gold alloys metallization and gold bonding on the p-n heterojunction devices for electrical current density-voltage characterization of the devices. Photovoltaic effect of hybrid quantum NS-devices with different NS-cycles are tested and recorded under various illumination intensities. Spectral response at long wavelength in infrared region beyond 1 μm originated from the presence of hybrid NSs is detected. © 2020 Elsevier B.V.
2.
Chikumpa, M; Zon,; Thainoi, S; Kiravittaya, S; Tandaechanurat, A; Nuntawong, N; Sopitpan, S; Yordsri, V; Thanachayanont, C; Kanjanachuchai, S; Ratanathammaphan, S; Panyakeow, S
Raman peak shifts by applied magnetic field in InSb/AlxIn1−xSb superlattices Journal Article
In: Materials Research Express, vol. 7, no. 10, 2020, ISSN: 20531591, (cited By 0).
@article{Chikumpa2020,
title = {Raman peak shifts by applied magnetic field in InSb/AlxIn1−xSb superlattices},
author = {M Chikumpa and Zon and S Thainoi and S Kiravittaya and A Tandaechanurat and N Nuntawong and S Sopitpan and V Yordsri and C Thanachayanont and S Kanjanachuchai and S Ratanathammaphan and S Panyakeow},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85095443053&doi=10.1088%2f2053-1591%2fabbded&partnerID=40&md5=af17ec520fd0c3b6962dd0d41f7d31e5},
doi = {10.1088/2053-1591/abbded},
issn = {20531591},
year = {2020},
date = {2020-01-01},
journal = {Materials Research Express},
volume = {7},
number = {10},
publisher = {IOP Publishing Ltd},
abstract = {InSb/Alxln1−xSb superlattices (SLs) are grown by molecular beam epitaxy on (001) InSb substrate and Raman scattering spectroscopy of the samples under magnetic field is investigated. Al contents in AlInSb of the samples are varied. All samples are characterized by atomic force microscopy (AFM), X-ray diffraction and Raman scattering spectroscopy. The Raman spectroscopy is done by using excitation laser with 633 nm wavelength and 2 μm beam spot under applied magnetic field from 0 to 170 mT. Both TO and LO Raman peaks from InSb are detected from all samples. There are Raman peak shift of both TO and LO by applied magnetic field. Stronger magnetic effect is found in LO than TO phonon modes. We attribute this effect to the symmetry breaking of the InSb/AlInSb interfaces since the observed roughness of the top InSb layer can qualitatively correlate with the shift. © 2020 The Author(s). Published by IOP Publishing Ltd},
note = {cited By 0},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
InSb/Alxln1−xSb superlattices (SLs) are grown by molecular beam epitaxy on (001) InSb substrate and Raman scattering spectroscopy of the samples under magnetic field is investigated. Al contents in AlInSb of the samples are varied. All samples are characterized by atomic force microscopy (AFM), X-ray diffraction and Raman scattering spectroscopy. The Raman spectroscopy is done by using excitation laser with 633 nm wavelength and 2 μm beam spot under applied magnetic field from 0 to 170 mT. Both TO and LO Raman peaks from InSb are detected from all samples. There are Raman peak shift of both TO and LO by applied magnetic field. Stronger magnetic effect is found in LO than TO phonon modes. We attribute this effect to the symmetry breaking of the InSb/AlInSb interfaces since the observed roughness of the top InSb layer can qualitatively correlate with the shift. © 2020 The Author(s). Published by IOP Publishing Ltd
3.
Rongrueangkul, K; Srisinsuphya, P; Thainoi, S; Kiravittaya, S; Nuntawong, N; Thornyanadacha, N; Sopitpan, S; Yordsri, V; Thanachayanont, C; Kanjanachuchai, S; Ratanathammaphan, S; Tandaechanurat, A; Panyakeow, S
Investigation of the Morphology of InSb/InAs Quantum Nanostripe Grown by Molecular Beam Epitaxy Journal Article
In: Physica Status Solidi (B) Basic Research, vol. 257, no. 2, 2020, ISSN: 03701972, (cited By 0).
@article{Rongrueangkul2020,
title = {Investigation of the Morphology of InSb/InAs Quantum Nanostripe Grown by Molecular Beam Epitaxy},
author = {K Rongrueangkul and P Srisinsuphya and S Thainoi and S Kiravittaya and N Nuntawong and N Thornyanadacha and S Sopitpan and V Yordsri and C Thanachayanont and S Kanjanachuchai and S Ratanathammaphan and A Tandaechanurat and S Panyakeow},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85073939493&doi=10.1002%2fpssb.201900374&partnerID=40&md5=34ed81ba697a222211525ff20e5a1904},
doi = {10.1002/pssb.201900374},
issn = {03701972},
year = {2020},
date = {2020-01-01},
journal = {Physica Status Solidi (B) Basic Research},
volume = {257},
number = {2},
publisher = {Wiley-VCH Verlag},
abstract = {The dimensions and morphologies of quantum nanostructures are keys to controlling an operating wavelength to a desirable wavelength range due to the quantum effect. The dimension and morphology evolutions of InSb/InAs quantum nanostructures grown by molecular beam epitaxy with respect to the number of InSb monolayers (MLs) are investigated. The formation of the quantum nanostructures is dominated by lateral growth, in which the morphology is further elongated as the number of MLs is increased. Such an anisotropic growth is explained by the difference in the surface energy along each direction, which corresponds to different atomic arrangements in the crystalline structure of InSb. Cross-sectional transmission electron microscopic images show a reduction in the lateral dimension and an increase in the height of the embedded InSb quantum nanostructures when they are embedded in the InAs matrix. The results herein provide a means for obtaining the precise control over dimensions and morphologies of the InSb/InAs nanostructures, which is essential for extending the operating wavelength further into the mid-infrared region. © 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim},
note = {cited By 0},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The dimensions and morphologies of quantum nanostructures are keys to controlling an operating wavelength to a desirable wavelength range due to the quantum effect. The dimension and morphology evolutions of InSb/InAs quantum nanostructures grown by molecular beam epitaxy with respect to the number of InSb monolayers (MLs) are investigated. The formation of the quantum nanostructures is dominated by lateral growth, in which the morphology is further elongated as the number of MLs is increased. Such an anisotropic growth is explained by the difference in the surface energy along each direction, which corresponds to different atomic arrangements in the crystalline structure of InSb. Cross-sectional transmission electron microscopic images show a reduction in the lateral dimension and an increase in the height of the embedded InSb quantum nanostructures when they are embedded in the InAs matrix. The results herein provide a means for obtaining the precise control over dimensions and morphologies of the InSb/InAs nanostructures, which is essential for extending the operating wavelength further into the mid-infrared region. © 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
4.
Zon,; Thainoi, S; Kiravittaya, S; Tandaechanurat, A; Kanjanachuchai, S; Ratanathammaphan, S; Panyakeow, S; Ota, Y; Iwamoto, S; Arakawa, Y
Photoluminescence properties as a function of growth mechanism for GaSb/GaAs quantum dots grown on Ge substrates Journal Article
In: Journal of Applied Physics, vol. 126, no. 8, 2019, ISSN: 00218979, (cited By 1).
@article{Zon2019a,
title = {Photoluminescence properties as a function of growth mechanism for GaSb/GaAs quantum dots grown on Ge substrates},
author = {Zon and S Thainoi and S Kiravittaya and A Tandaechanurat and S Kanjanachuchai and S Ratanathammaphan and S Panyakeow and Y Ota and S Iwamoto and Y Arakawa},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85071276629&doi=10.1063%2f1.5097261&partnerID=40&md5=bef9e28bd89a90e4e5985d4c8d55b84e},
doi = {10.1063/1.5097261},
issn = {00218979},
year = {2019},
date = {2019-01-01},
journal = {Journal of Applied Physics},
volume = {126},
number = {8},
publisher = {American Institute of Physics Inc.},
abstract = {In this work, we use photoluminescence (PL) spectroscopy to investigate how self-assembled GaSb/GaAs quantum dots (QDs) depend on their growth mechanism. Carrier transfer (i.e., carrier recombination in QDs and escape through the barrier layer) is investigated as a function of excitation-power- and temperature-dependent PL measurements. A drastic blueshift of the QD peak energy from 1.23 to 1.30 eV and a further shift to 1.33 eV reveal the influence of the GaSb growth rate and the growth temperature on the optical properties of these QDs. The thermal activation energy is extracted from the temperature-dependent PL by fitting the integrated PL intensity of the QD peaks to the Arrhenius relation. The QDs grown at the growth rate of 0.1 monolayers/s at 450 °C have higher thermal activation energy (109 meV) than those grown at a lower growth rate and higher QD growth temperature. The observed PL characteristics are discussed in terms of QD size, uniformity of QDs, and material intermixing occurring during QD growth on the buffer layer and capping layer. © 2019 Author(s).},
note = {cited By 1},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In this work, we use photoluminescence (PL) spectroscopy to investigate how self-assembled GaSb/GaAs quantum dots (QDs) depend on their growth mechanism. Carrier transfer (i.e., carrier recombination in QDs and escape through the barrier layer) is investigated as a function of excitation-power- and temperature-dependent PL measurements. A drastic blueshift of the QD peak energy from 1.23 to 1.30 eV and a further shift to 1.33 eV reveal the influence of the GaSb growth rate and the growth temperature on the optical properties of these QDs. The thermal activation energy is extracted from the temperature-dependent PL by fitting the integrated PL intensity of the QD peaks to the Arrhenius relation. The QDs grown at the growth rate of 0.1 monolayers/s at 450 °C have higher thermal activation energy (109 meV) than those grown at a lower growth rate and higher QD growth temperature. The observed PL characteristics are discussed in terms of QD size, uniformity of QDs, and material intermixing occurring during QD growth on the buffer layer and capping layer. © 2019 Author(s).
5.
Srisinsuphya, P; Rongrueangkul, K; Khanchaitham, R; Thainoi, S; Kiravittaya, S; Nuntawong, N; Sopitpan, S; Yordsri, V; Thanachayanont, C; Kanjanachuchai, S; Ratanathammaphan, S; Tandaechanurat, A; Panyakeow, S
InSb/InAs quantum nano-stripes grown by molecular beam epitaxy and its photoluminescence at mid-infrared wavelength Journal Article
In: Journal of Crystal Growth, vol. 514, pp. 36-39, 2019, ISSN: 00220248, (cited By 2).
@article{Srisinsuphya2019,
title = {InSb/InAs quantum nano-stripes grown by molecular beam epitaxy and its photoluminescence at mid-infrared wavelength},
author = {P Srisinsuphya and K Rongrueangkul and R Khanchaitham and S Thainoi and S Kiravittaya and N Nuntawong and S Sopitpan and V Yordsri and C Thanachayanont and S Kanjanachuchai and S Ratanathammaphan and A Tandaechanurat and S Panyakeow},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85062228511&doi=10.1016%2fj.jcrysgro.2019.02.062&partnerID=40&md5=340a9226777c2d049a0a162df69bbf60},
doi = {10.1016/j.jcrysgro.2019.02.062},
issn = {00220248},
year = {2019},
date = {2019-01-01},
journal = {Journal of Crystal Growth},
volume = {514},
pages = {36-39},
publisher = {Elsevier B.V.},
abstract = {Distinct InSb/InAs quantum nano-stripes possessing type-II band alignment with a broken gap are grown using molecular beam epitaxy with low substrate temperature and slow growth rate, aiming for light emission in a mid-infrared range. The quantum nano-stripes are shown to emit light at a wavelength of 3.1 µm. The excitation power dependence of photoluminescence spectra from the quantum nano-stripes reveals a clear linear blueshift with the third root of the excitation power, which is a unique property of the quantum nanostructures with type-II band alignment. The demonstrated mid-infrared light emission from the InSb/InAs quantum nano-stripes would offer a promising pathway for realizing practical, highly-efficient, and room-temperature-operating mid-infrared light sources and detectors. © 2019 Elsevier B.V.},
note = {cited By 2},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Distinct InSb/InAs quantum nano-stripes possessing type-II band alignment with a broken gap are grown using molecular beam epitaxy with low substrate temperature and slow growth rate, aiming for light emission in a mid-infrared range. The quantum nano-stripes are shown to emit light at a wavelength of 3.1 µm. The excitation power dependence of photoluminescence spectra from the quantum nano-stripes reveals a clear linear blueshift with the third root of the excitation power, which is a unique property of the quantum nanostructures with type-II band alignment. The demonstrated mid-infrared light emission from the InSb/InAs quantum nano-stripes would offer a promising pathway for realizing practical, highly-efficient, and room-temperature-operating mid-infrared light sources and detectors. © 2019 Elsevier B.V.
6.
Zon,; Thainoi, S; Kiravittaya, S; Tandaechanurat, A; Nuntawong, N; Sopitpan, S; Yordsri, V; Thanachayanont, C; Kanjanachuchai, S; Ratanathammaphan, S; Panyakeow, S
Anti-phase domain induced morphological differences of self-assembled InSb/GaAs quantum dots grown on (0 0 1) Ge substrate Journal Article
In: Journal of Crystal Growth, vol. 512, pp. 136-141, 2019, ISSN: 00220248, (cited By 0).
@article{Zon2019b,
title = {Anti-phase domain induced morphological differences of self-assembled InSb/GaAs quantum dots grown on (0 0 1) Ge substrate},
author = {Zon and S Thainoi and S Kiravittaya and A Tandaechanurat and N Nuntawong and S Sopitpan and V Yordsri and C Thanachayanont and S Kanjanachuchai and S Ratanathammaphan and S Panyakeow},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85061527393&doi=10.1016%2fj.jcrysgro.2019.02.015&partnerID=40&md5=58e0e65fbdee217951526b20093085ff},
doi = {10.1016/j.jcrysgro.2019.02.015},
issn = {00220248},
year = {2019},
date = {2019-01-01},
journal = {Journal of Crystal Growth},
volume = {512},
pages = {136-141},
publisher = {Elsevier B.V.},
abstract = {The effects of growth temperature, growth rate and local growth position on the morphology of self-assembled InSb/GaAs quantum dots (QDs) on (0 0 1) Ge substrate are investigated. It is found that for low growth rates, anti-phase domain (APD) boundaries formed during the growth of GaAs on Ge can effectively act as the preferential nucleation position of InSb QDs. For high growth rates, InSb/GaAs QDs nucleate on both the APD boundary and the APD surface, leading to high density-InSb QDs. The QD morphologies on the APD boundary and the APD surface are distinctly different. The roles of growth rate and local growth position on the morphology of realized QDs are described. By varying the growth conditions, low density and locally aligned QDs as well as high density InSb QDs can be obtained. © 2019},
note = {cited By 0},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The effects of growth temperature, growth rate and local growth position on the morphology of self-assembled InSb/GaAs quantum dots (QDs) on (0 0 1) Ge substrate are investigated. It is found that for low growth rates, anti-phase domain (APD) boundaries formed during the growth of GaAs on Ge can effectively act as the preferential nucleation position of InSb QDs. For high growth rates, InSb/GaAs QDs nucleate on both the APD boundary and the APD surface, leading to high density-InSb QDs. The QD morphologies on the APD boundary and the APD surface are distinctly different. The roles of growth rate and local growth position on the morphology of realized QDs are described. By varying the growth conditions, low density and locally aligned QDs as well as high density InSb QDs can be obtained. © 2019
7.
Lekwongderm, P; Chumkaew, R; Thainoi, S; Kiravittaya, S; Tandaechanurat, A; Nuntawong, N; Sopitpan, S; Yordsri, V; Thanachayanont, C; Kanjanachuchai, S; Ratanathammaphan, S; Panyakeow, S
In: Journal of Crystal Growth, vol. 512, pp. 198-202, 2019, ISSN: 00220248, (cited By 1).
@article{Lekwongderm2019,
title = {Study on Raman spectroscopy of InSb nano-stripes grown on GaSb substrate by molecular beam epitaxy and their Raman peak shift with magnetic field},
author = {P Lekwongderm and R Chumkaew and S Thainoi and S Kiravittaya and A Tandaechanurat and N Nuntawong and S Sopitpan and V Yordsri and C Thanachayanont and S Kanjanachuchai and S Ratanathammaphan and S Panyakeow},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85061693748&doi=10.1016%2fj.jcrysgro.2019.02.033&partnerID=40&md5=c9f2956e9c12372286a99fceaa0503bf},
doi = {10.1016/j.jcrysgro.2019.02.033},
issn = {00220248},
year = {2019},
date = {2019-01-01},
journal = {Journal of Crystal Growth},
volume = {512},
pages = {198-202},
publisher = {Elsevier B.V.},
abstract = {We report on the Raman spectroscopy of self-assembled InSb nano-stripes grown on (0 0 1) GaSb substrate by molecular beam epitaxy. The nano-stripes have a truncated pyramidal shape with the typical dimension of ∼150 × 200 × 25 nm 3 . Raman spectroscopy is applied to probe the phonon-related properties of the InSb nano-stripes. Raman spectroscopy shows slight redshifts of the InSb-related phonon peaks when the excitation wavelength is increased. When a magnetic field is applied, blueshifts of these peaks are observed. Transmission electron microscopy is utilized to relate the structural information of the InSb nano-stripes and their Raman properties. © 2019},
note = {cited By 1},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We report on the Raman spectroscopy of self-assembled InSb nano-stripes grown on (0 0 1) GaSb substrate by molecular beam epitaxy. The nano-stripes have a truncated pyramidal shape with the typical dimension of ∼150 × 200 × 25 nm 3 . Raman spectroscopy is applied to probe the phonon-related properties of the InSb nano-stripes. Raman spectroscopy shows slight redshifts of the InSb-related phonon peaks when the excitation wavelength is increased. When a magnetic field is applied, blueshifts of these peaks are observed. Transmission electron microscopy is utilized to relate the structural information of the InSb nano-stripes and their Raman properties. © 2019
8.
Chevuntulak, C; Rakpaises, T; Sridumrongsak, N; Thainoi, S; Kiravittaya, S; Nuntawong, N; Sopitpan, S; Yordsri, V; Thanachayanont, C; Kanjanachuchai, S; Ratanathammaphan, S; Tandaechanurat, A; Panyakeow, S
Molecular beam epitaxial growth of interdigitated quantum dots for heterojunction solar cells Journal Article
In: Journal of Crystal Growth, vol. 512, pp. 159-163, 2019, ISSN: 00220248, (cited By 1).
@article{Chevuntulak2019,
title = {Molecular beam epitaxial growth of interdigitated quantum dots for heterojunction solar cells},
author = {C Chevuntulak and T Rakpaises and N Sridumrongsak and S Thainoi and S Kiravittaya and N Nuntawong and S Sopitpan and V Yordsri and C Thanachayanont and S Kanjanachuchai and S Ratanathammaphan and A Tandaechanurat and S Panyakeow},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85061674884&doi=10.1016%2fj.jcrysgro.2019.02.031&partnerID=40&md5=dfa591a95890f7fb57db81c384058dba},
doi = {10.1016/j.jcrysgro.2019.02.031},
issn = {00220248},
year = {2019},
date = {2019-01-01},
journal = {Journal of Crystal Growth},
volume = {512},
pages = {159-163},
publisher = {Elsevier B.V.},
abstract = {Interdigitated quantum dots, which are multiple stacks of type-I InAs/GaAs quantum dots and type-II GaSb/GaAs quantum dots, are grown using molecular beam epitaxy. By incorporating the interdigitated quantum dots into a p-i-n AlGaAs/GaAs heterojunction solar cell structure, we demonstrate a photovoltaic effect with a 20.6% improvement in open-circuit voltage, when compared to that of another cell incorporating the same quantum dots but with a p-i-n GaAs homojunction architecture. A transmission electron microscopy is performed to analyze strain-induced defects created in the multi-stack quantum dot structures. The heterojunction solar cell incorporating the interdigitated quantum dots realized in this work would find potential applications in high-efficiency single-junction intermediate band solar cells operating under concentrated sunlight. © 2019 Elsevier B.V.},
note = {cited By 1},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Interdigitated quantum dots, which are multiple stacks of type-I InAs/GaAs quantum dots and type-II GaSb/GaAs quantum dots, are grown using molecular beam epitaxy. By incorporating the interdigitated quantum dots into a p-i-n AlGaAs/GaAs heterojunction solar cell structure, we demonstrate a photovoltaic effect with a 20.6% improvement in open-circuit voltage, when compared to that of another cell incorporating the same quantum dots but with a p-i-n GaAs homojunction architecture. A transmission electron microscopy is performed to analyze strain-induced defects created in the multi-stack quantum dot structures. The heterojunction solar cell incorporating the interdigitated quantum dots realized in this work would find potential applications in high-efficiency single-junction intermediate band solar cells operating under concentrated sunlight. © 2019 Elsevier B.V.
9.
Posri, S; Thainoi, S; Kiravittaya, S; Tandaechanurat, A; Nuntawong, N; Sopitpan, S; Yordsri, V; Thanachayanont, C; Kanjanachuchai, S; Ratanathammaphan, S; Panyakeow, S
Growth and Photoluminescence Properties of InSb/GaSb Nano-Stripes Grown by Molecular Beam Epitaxy Journal Article
In: Physica Status Solidi (A) Applications and Materials Science, vol. 216, no. 1, 2019, ISSN: 18626300, (cited By 2).
@article{Posri2019,
title = {Growth and Photoluminescence Properties of InSb/GaSb Nano-Stripes Grown by Molecular Beam Epitaxy},
author = {S Posri and S Thainoi and S Kiravittaya and A Tandaechanurat and N Nuntawong and S Sopitpan and V Yordsri and C Thanachayanont and S Kanjanachuchai and S Ratanathammaphan and S Panyakeow},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85054885756&doi=10.1002%2fpssa.201800498&partnerID=40&md5=c3bd9d906a071150f51c67014064263e},
doi = {10.1002/pssa.201800498},
issn = {18626300},
year = {2019},
date = {2019-01-01},
journal = {Physica Status Solidi (A) Applications and Materials Science},
volume = {216},
number = {1},
publisher = {Wiley-VCH Verlag},
abstract = {In this study, the growth and photoluminescence (PL) properties of InSb/GaSb nano-stripes grown by molecular beam epitaxy on (001) GaSb substrate are reported. In situ reflection high-energy electron diffraction observation during InSb growth shows that the growth of InSb on GaSb surface is in Stranski–Krastanov mode and results in nano-stripe formation. The obtained nano-stripes have rectangular-based structure with the height of 25.2 ± 4.0 nm and they are elongated along [110] direction. PL emission from buried InSb/GaSb nano-stripes shows the emission peak at ≈1850 nm (0.67 eV). According to the emission energy and the structural information, low In content of ≈0.24 in nominally grown InSb/GaSb nano-stripe is estimated. Power-dependent PL spectroscopy shows a linear relation between integrated PL intensity and the excitation power. Thermal activation energy of ≈20 meV from InSb nano-stripe emission is extracted from the temperature-dependent PL spectroscopy. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim},
note = {cited By 2},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In this study, the growth and photoluminescence (PL) properties of InSb/GaSb nano-stripes grown by molecular beam epitaxy on (001) GaSb substrate are reported. In situ reflection high-energy electron diffraction observation during InSb growth shows that the growth of InSb on GaSb surface is in Stranski–Krastanov mode and results in nano-stripe formation. The obtained nano-stripes have rectangular-based structure with the height of 25.2 ± 4.0 nm and they are elongated along [110] direction. PL emission from buried InSb/GaSb nano-stripes shows the emission peak at ≈1850 nm (0.67 eV). According to the emission energy and the structural information, low In content of ≈0.24 in nominally grown InSb/GaSb nano-stripe is estimated. Power-dependent PL spectroscopy shows a linear relation between integrated PL intensity and the excitation power. Thermal activation energy of ≈20 meV from InSb nano-stripe emission is extracted from the temperature-dependent PL spectroscopy. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
10.
Zon,; Phienlumlert, P; Thainoi, S; Kiravittaya, S; Tandaechanurat, A; Nuntawong, N; Sopitpan, S; Yordsri, V; Thanachayanont, C; Kanjanachuchai, S; Ratanathammaphan, S; Panyakeow, S; Ota, Y; Iwamoto, S; Arakawa, Y
Growth-Rate-Dependent Properties of GaSb/GaAs Quantum Dots on (001) Ge Substrate by Molecular Beam Epitaxy Journal Article
In: Physica Status Solidi (A) Applications and Materials Science, vol. 216, no. 1, 2019, ISSN: 18626300, (cited By 4).
@article{Zon2019,
title = {Growth-Rate-Dependent Properties of GaSb/GaAs Quantum Dots on (001) Ge Substrate by Molecular Beam Epitaxy},
author = {Zon and P Phienlumlert and S Thainoi and S Kiravittaya and A Tandaechanurat and N Nuntawong and S Sopitpan and V Yordsri and C Thanachayanont and S Kanjanachuchai and S Ratanathammaphan and S Panyakeow and Y Ota and S Iwamoto and Y Arakawa},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85054573343&doi=10.1002%2fpssa.201800499&partnerID=40&md5=03f4c06b9d368e1049355d20d0bdcd63},
doi = {10.1002/pssa.201800499},
issn = {18626300},
year = {2019},
date = {2019-01-01},
journal = {Physica Status Solidi (A) Applications and Materials Science},
volume = {216},
number = {1},
publisher = {Wiley-VCH Verlag},
abstract = {Tuning growth of nanostructures can provide additional routes to engineer their characteristics. In this work, the authors report on a combined growth of GaSb/GaAs quantum dots (QDs) and growth of GaAs on (001) Ge substrate. Surface decorated with GaAs anti-phase domain is the initial template to investigate the growth-rate effects on the growth of self-assembled GaSb QDs. By varying the GaSb growth rates, QD ensembles with different morphologies are formed. Perpendicular alignment of elongated GaSb QDs is observed. Cross-sectional transmission electron microscopic images show a substantial reduction of lateral QD size when it is buried in GaAs matrix. Raman scattering as well as power-dependent photoluminescence spectroscopies are performed to reveal the optical properties of the nanostructures. Type-II band alignment characteristic is confirmed. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim},
note = {cited By 4},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Tuning growth of nanostructures can provide additional routes to engineer their characteristics. In this work, the authors report on a combined growth of GaSb/GaAs quantum dots (QDs) and growth of GaAs on (001) Ge substrate. Surface decorated with GaAs anti-phase domain is the initial template to investigate the growth-rate effects on the growth of self-assembled GaSb QDs. By varying the GaSb growth rates, QD ensembles with different morphologies are formed. Perpendicular alignment of elongated GaSb QDs is observed. Cross-sectional transmission electron microscopic images show a substantial reduction of lateral QD size when it is buried in GaAs matrix. Raman scattering as well as power-dependent photoluminescence spectroscopies are performed to reveal the optical properties of the nanostructures. Type-II band alignment characteristic is confirmed. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
11.
Vorathamrong, S; Panyakeow, S; Ratanathammaphan, S; Praserthdam, P
Surface evolution of native silicon oxide layer and its effects on the growth of self-assisted VLS GaAs nanowires Journal Article
In: AIP Advances, vol. 9, no. 2, 2019, ISSN: 21583226, (cited By 0).
@article{Vorathamrong2019,
title = {Surface evolution of native silicon oxide layer and its effects on the growth of self-assisted VLS GaAs nanowires},
author = {S Vorathamrong and S Panyakeow and S Ratanathammaphan and P Praserthdam},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85062210634&doi=10.1063%2f1.5084344&partnerID=40&md5=5f340c4932eca70b06358f77eb46d479},
doi = {10.1063/1.5084344},
issn = {21583226},
year = {2019},
date = {2019-01-01},
journal = {AIP Advances},
volume = {9},
number = {2},
publisher = {American Institute of Physics Inc.},
abstract = {This research focuses on the impact of native SiO 2 layer evolution, occurring on the surfaces of Si(111) substrates on the morphological and structural properties of self-assisted GaAs nanowires. GaAs nanowires growth were grown on Si(111) substrates, already covered with native SiO 2 developing in different states with identical growth parameters including growth temperature, growth time, and Ga and As flux, using self-assisted VLS process by MBE technique. Results from nanowire samples and substrates were compared to understand the correlation between the changes in appearance of native SiO 2 layer and the changes in the growth pattern of the nanowires. © 2019 Author(s).},
note = {cited By 0},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
This research focuses on the impact of native SiO 2 layer evolution, occurring on the surfaces of Si(111) substrates on the morphological and structural properties of self-assisted GaAs nanowires. GaAs nanowires growth were grown on Si(111) substrates, already covered with native SiO 2 developing in different states with identical growth parameters including growth temperature, growth time, and Ga and As flux, using self-assisted VLS process by MBE technique. Results from nanowire samples and substrates were compared to understand the correlation between the changes in appearance of native SiO 2 layer and the changes in the growth pattern of the nanowires. © 2019 Author(s).
12.
Narabadeesuphakorn, P; Thainoi, S; Tandaechanurat, A; Kiravittaya, S; Nuntawong, N; Sopitopan, S; Yordsri, V; Thanachayanont, C; Kanjanachuchai, S; Ratanathammaphan, S; Panyakeow, S
Twin InSb/GaAs quantum nano-stripes: Growth optimization and related properties Journal Article
In: Journal of Crystal Growth, vol. 487, pp. 40-44, 2018, ISSN: 00220248, (cited By 5).
@article{Narabadeesuphakorn2018,
title = {Twin InSb/GaAs quantum nano-stripes: Growth optimization and related properties},
author = {P Narabadeesuphakorn and S Thainoi and A Tandaechanurat and S Kiravittaya and N Nuntawong and S Sopitopan and V Yordsri and C Thanachayanont and S Kanjanachuchai and S Ratanathammaphan and S Panyakeow},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85042190688&doi=10.1016%2fj.jcrysgro.2018.01.030&partnerID=40&md5=24d51889bcf6105d693b0d9f5a69b87e},
doi = {10.1016/j.jcrysgro.2018.01.030},
issn = {00220248},
year = {2018},
date = {2018-01-01},
journal = {Journal of Crystal Growth},
volume = {487},
pages = {40-44},
publisher = {Elsevier B.V.},
abstract = {Growth of InSb/GaAs quantum nanostructures on GaAs substrate by using molecular beam epitaxy with low growth temperature and slow growth rate typically results in a mixture of isolated and paired nano-stripe structures, which are termed as single and twin nano-stripes, respectively. In this work, we investigate the growth conditions to maximize the number ratio between twin and single nano-stripes. The highest percentage of the twin nano-stripes of up to 59% was achieved by optimizing the substrate temperature and the nano-stripe growth rate. Transmission electron microscopy reveals the substantial size and height reduction of the buried nano-stripes. We also observed the Raman shift and photon emission from our twin nano-stripes. These twin nano-stripes are promising for spintronics and quantum computing devices. © 2018 Elsevier B.V.},
note = {cited By 5},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Growth of InSb/GaAs quantum nanostructures on GaAs substrate by using molecular beam epitaxy with low growth temperature and slow growth rate typically results in a mixture of isolated and paired nano-stripe structures, which are termed as single and twin nano-stripes, respectively. In this work, we investigate the growth conditions to maximize the number ratio between twin and single nano-stripes. The highest percentage of the twin nano-stripes of up to 59% was achieved by optimizing the substrate temperature and the nano-stripe growth rate. Transmission electron microscopy reveals the substantial size and height reduction of the buried nano-stripes. We also observed the Raman shift and photon emission from our twin nano-stripes. These twin nano-stripes are promising for spintronics and quantum computing devices. © 2018 Elsevier B.V.
13.
Thainoi, S; Kiravittaya, S; Poempool, T; Zon,; Nuntawong, N; Sopitpan, S; Kanjanachuchai, S; Ratanathammaphan, S; Panyakeow, S
Molecular beam epitaxy growth of InSb/GaAs quantum nanostructures Journal Article
In: Journal of Crystal Growth, vol. 477, pp. 30-33, 2017, ISSN: 00220248, (cited By 7).
@article{Thainoi2017,
title = {Molecular beam epitaxy growth of InSb/GaAs quantum nanostructures},
author = {S Thainoi and S Kiravittaya and T Poempool and Zon and N Nuntawong and S Sopitpan and S Kanjanachuchai and S Ratanathammaphan and S Panyakeow},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85010189136&doi=10.1016%2fj.jcrysgro.2017.01.011&partnerID=40&md5=8ac8c045bcb517b94f88d6fd9d75d1db},
doi = {10.1016/j.jcrysgro.2017.01.011},
issn = {00220248},
year = {2017},
date = {2017-01-01},
journal = {Journal of Crystal Growth},
volume = {477},
pages = {30-33},
publisher = {Elsevier B.V.},
abstract = {InSb/GaAs nanostructures grown by solid-source molecular beam epitaxy are investigated in this work. Three-dimensional dot-like InSb nanostructures are obtained by self-assembled growth at relatively low growth temperatures (250–300 °C) with slow InSb growth rate. Nanostructure base is typically elongated. Facet analysis of the free-standing InSb nanostructure grown at 250 °C shows that each nanostructure has flat top (001) surface while side facets are along <11n> directions. In contrast, InSb nanostructures grown at higher temperature show rather smooth surfaces. Analysis of their size distributions shows that the size inhomogeneity increases with the growth temperature. Moreover, Raman spectroscopy reveals both InSb-related peaks at 181 and 189 cm−1 and GaAs-related peaks at 268 and 293 cm−1. Raman spectroscopy with different excitation wavelengths is applied to probe residual strain in subsurface GaAs layer. © 2017 Elsevier B.V.},
note = {cited By 7},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
InSb/GaAs nanostructures grown by solid-source molecular beam epitaxy are investigated in this work. Three-dimensional dot-like InSb nanostructures are obtained by self-assembled growth at relatively low growth temperatures (250–300 °C) with slow InSb growth rate. Nanostructure base is typically elongated. Facet analysis of the free-standing InSb nanostructure grown at 250 °C shows that each nanostructure has flat top (001) surface while side facets are along <11n> directions. In contrast, InSb nanostructures grown at higher temperature show rather smooth surfaces. Analysis of their size distributions shows that the size inhomogeneity increases with the growth temperature. Moreover, Raman spectroscopy reveals both InSb-related peaks at 181 and 189 cm−1 and GaAs-related peaks at 268 and 293 cm−1. Raman spectroscopy with different excitation wavelengths is applied to probe residual strain in subsurface GaAs layer. © 2017 Elsevier B.V.
14.
Thainoi, S; Kiravittaya, S; Poempool, T; Zon,; Sopitpan, S; Kanjanachuchai, S; Ratanathammaphan, S; Panyakeow, S
Growth of truncated pyramidal InSb nanostructures on GaAs substrate Journal Article
In: Journal of Crystal Growth, vol. 468, pp. 737-739, 2017, ISSN: 00220248, (cited By 6).
@article{Thainoi2017a,
title = {Growth of truncated pyramidal InSb nanostructures on GaAs substrate},
author = {S Thainoi and S Kiravittaya and T Poempool and Zon and S Sopitpan and S Kanjanachuchai and S Ratanathammaphan and S Panyakeow},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85009945358&doi=10.1016%2fj.jcrysgro.2016.11.093&partnerID=40&md5=097da5f0c36275c55c6370831e201de5},
doi = {10.1016/j.jcrysgro.2016.11.093},
issn = {00220248},
year = {2017},
date = {2017-01-01},
journal = {Journal of Crystal Growth},
volume = {468},
pages = {737-739},
publisher = {Elsevier B.V.},
abstract = {Growth and structural characterization of InSb nanostructures formed on GaAs is presented. Saturated InSb nanostructure have a truncated pyramidal shape with rectangular base. In addition, some InSb nanostructures have twin truncated pyramidal configurations. The twin truncated pyramids align in parallel with each other and along [110] direction. We attribute the formation of rectangular base to the growth of highly mismatched InSb/GaAs system while the formation of twin configuration due to the nucleation of InSb islands on top of two-dimensional InSb plateau. The latter is suggested by an observation on the initial state of InSb nanostructure formation. © 2016 Elsevier B.V.},
note = {cited By 6},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Growth and structural characterization of InSb nanostructures formed on GaAs is presented. Saturated InSb nanostructure have a truncated pyramidal shape with rectangular base. In addition, some InSb nanostructures have twin truncated pyramidal configurations. The twin truncated pyramids align in parallel with each other and along [110] direction. We attribute the formation of rectangular base to the growth of highly mismatched InSb/GaAs system while the formation of twin configuration due to the nucleation of InSb islands on top of two-dimensional InSb plateau. The latter is suggested by an observation on the initial state of InSb nanostructure formation. © 2016 Elsevier B.V.
15.
Zon,; Poempool, T; Kiravittaya, S; Sopitpan, S; Thainoi, S; Kanjanachuchai, S; Ratanathammaphan, S; Panyakeow, S
Morphology of self-assembled InSb/GaAs quantum dots on Ge substrate Journal Article
In: Journal of Crystal Growth, vol. 468, pp. 541-546, 2017, ISSN: 00220248, (cited By 2).
@article{Zon2017,
title = {Morphology of self-assembled InSb/GaAs quantum dots on Ge substrate},
author = {Zon and T Poempool and S Kiravittaya and S Sopitpan and S Thainoi and S Kanjanachuchai and S Ratanathammaphan and S Panyakeow},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85006981077&doi=10.1016%2fj.jcrysgro.2016.11.017&partnerID=40&md5=c22a57d3f971e5a2c5bbcb09d988e61e},
doi = {10.1016/j.jcrysgro.2016.11.017},
issn = {00220248},
year = {2017},
date = {2017-01-01},
journal = {Journal of Crystal Growth},
volume = {468},
pages = {541-546},
publisher = {Elsevier B.V.},
abstract = {In this work, we report on the growth of self-assembled InSb/GaAs quantum dots (QDs) on (001) Ge substrate by molecular beam epitaxy. Due to the polar/non-polar nature of GaAs grown on Ge, antiphase domains are formed. Effects of the domain and QD growth temperature on the morphology of realized QDs are presented. InSb QDs are mostly formed at the antiphase-domain boundaries (APBs). The QD size, shape and density are varied with the QD growth temperature. These free-standing QDs have irregular lens and stripe-shapes with 10n side facets according to the analysis of atomic force microscopy images. InSb QDs is formed at the APBs, where two orthogonal GaAs surfaces are met. © 2016 Elsevier B.V.},
note = {cited By 2},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In this work, we report on the growth of self-assembled InSb/GaAs quantum dots (QDs) on (001) Ge substrate by molecular beam epitaxy. Due to the polar/non-polar nature of GaAs grown on Ge, antiphase domains are formed. Effects of the domain and QD growth temperature on the morphology of realized QDs are presented. InSb QDs are mostly formed at the antiphase-domain boundaries (APBs). The QD size, shape and density are varied with the QD growth temperature. These free-standing QDs have irregular lens and stripe-shapes with 10n side facets according to the analysis of atomic force microscopy images. InSb QDs is formed at the APBs, where two orthogonal GaAs surfaces are met. © 2016 Elsevier B.V.
16.
Vorathamrong, S; Ratanathammaphan, S; Panyakeow, S; Praserthdam, P; Tongyam, C
Effect of substrate temperature on self-assisted GaAs nanowires grown by Molecular Beam Epitaxy on GaAs (111)B substrates without SiO2 layer Journal Article
In: Journal of Crystal Growth, vol. 477, pp. 217-220, 2017, ISSN: 00220248, (cited By 1).
@article{Vorathamrong2017a,
title = {Effect of substrate temperature on self-assisted GaAs nanowires grown by Molecular Beam Epitaxy on GaAs (111)B substrates without SiO2 layer},
author = {S Vorathamrong and S Ratanathammaphan and S Panyakeow and P Praserthdam and C Tongyam},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85016748432&doi=10.1016%2fj.jcrysgro.2017.03.005&partnerID=40&md5=15abb7123ad81b7b640b08d13288a2bf},
doi = {10.1016/j.jcrysgro.2017.03.005},
issn = {00220248},
year = {2017},
date = {2017-01-01},
journal = {Journal of Crystal Growth},
volume = {477},
pages = {217-220},
publisher = {Elsevier B.V.},
abstract = {In this work, we demonstrate a self-assisted VLS growth of GaAs nanowires directly on GaAs (111)B substrates without assistance of SiO2 layer. We believe that with this technique, we can overcome some inherent problems that usually occur in conventional self-assisted VLS growth and simplify the process. Moreover, to study the effect of substrate temperature, each nanowire sample was fabricated at the different temperature from 400 °C to 600 °C using Molecular Beam Epitaxy (MBE) technique. Surface morphology, elemental composition, and crystal structure of nanowire samples were characterized by Scanning Electron Microscope (SEM), Energy-dispersive X-ray spectroscopy (EDX), and X-ray Diffraction Analysis (XRD) respectively. © 2017 Elsevier B.V.},
note = {cited By 1},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In this work, we demonstrate a self-assisted VLS growth of GaAs nanowires directly on GaAs (111)B substrates without assistance of SiO2 layer. We believe that with this technique, we can overcome some inherent problems that usually occur in conventional self-assisted VLS growth and simplify the process. Moreover, to study the effect of substrate temperature, each nanowire sample was fabricated at the different temperature from 400 °C to 600 °C using Molecular Beam Epitaxy (MBE) technique. Surface morphology, elemental composition, and crystal structure of nanowire samples were characterized by Scanning Electron Microscope (SEM), Energy-dispersive X-ray spectroscopy (EDX), and X-ray Diffraction Analysis (XRD) respectively. © 2017 Elsevier B.V.
17.
Vorathamrong, S; Panyakeow, S; Ratanathammaphan, S; Praserthdam, P; Tongyam, C
Observation of self-assisted GaAs nanowire growth by molecular beam epitaxy on GaAs (1 1 1)B without SiO2 layer Journal Article
In: Materials Research Express, vol. 4, no. 9, 2017, ISSN: 20531591, (cited By 2).
@article{Vorathamrong2017b,
title = {Observation of self-assisted GaAs nanowire growth by molecular beam epitaxy on GaAs (1 1 1)B without SiO2 layer},
author = {S Vorathamrong and S Panyakeow and S Ratanathammaphan and P Praserthdam and C Tongyam},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85030673178&doi=10.1088%2f2053-1591%2faa88fc&partnerID=40&md5=f2997bfda3da8096b8ebee5bc34aeab9},
doi = {10.1088/2053-1591/aa88fc},
issn = {20531591},
year = {2017},
date = {2017-01-01},
journal = {Materials Research Express},
volume = {4},
number = {9},
publisher = {Institute of Physics Publishing},
abstract = {GaAs nanowire growth was performed on bare GaAs (1 1 1)B substrates by molecular beam epitaxy technique. A small adjustment was made to the conventional self-assisted VLS growth by removing covered SiO2 layer and growing nanowires directly on the substrate surface in order to eliminate some issues that occur in the conventional self-assisted VLS growth. To study the growth mechanism, growth time was varied as a growth parameter. Nanowire crystal structure was investigated by XRD analysis. Evolution of surface morphology along with RHEED patterns were utilized to determine characteristics of the growth. © 2017 IOP Publishing Ltd.},
note = {cited By 2},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
GaAs nanowire growth was performed on bare GaAs (1 1 1)B substrates by molecular beam epitaxy technique. A small adjustment was made to the conventional self-assisted VLS growth by removing covered SiO2 layer and growing nanowires directly on the substrate surface in order to eliminate some issues that occur in the conventional self-assisted VLS growth. To study the growth mechanism, growth time was varied as a growth parameter. Nanowire crystal structure was investigated by XRD analysis. Evolution of surface morphology along with RHEED patterns were utilized to determine characteristics of the growth. © 2017 IOP Publishing Ltd.
18.
Zon,; Poempool, T; Kiravittaya, S; Nuntawong, N; Sopitpan, S; Thainoi, S; Kanjanachuchai, S; Ratanathammaphan, S; Panyakeow, S
Raman and photoluminescence properties of type II GaSb/GaAs quantum dots on (001) Ge substrate Journal Article
In: Electronic Materials Letters, vol. 12, no. 4, pp. 517-523, 2016, ISSN: 17388090, (cited By 6).
@article{Zon2016,
title = {Raman and photoluminescence properties of type II GaSb/GaAs quantum dots on (001) Ge substrate},
author = {Zon and T Poempool and S Kiravittaya and N Nuntawong and S Sopitpan and S Thainoi and S Kanjanachuchai and S Ratanathammaphan and S Panyakeow},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84978998455&doi=10.1007%2fs13391-016-4016-x&partnerID=40&md5=8a3940d683a94fdcad4b59e626954f77},
doi = {10.1007/s13391-016-4016-x},
issn = {17388090},
year = {2016},
date = {2016-01-01},
journal = {Electronic Materials Letters},
volume = {12},
number = {4},
pages = {517-523},
publisher = {Kluwer Academic Publishers},
abstract = {We investigate structural Raman and photoluminescence properties of type II GaSb/GaAs quantum dots (QDs) grown on (001) Ge substrate by molecular beam epitaxy. Array of self-assembled GaSb QDs having an areal density of ∼1.66 × 1010 dots/cm2 is obtained by a growth at relatively low substrate temperature (450 °C) on a GaAs surface segmented into anti-phase domains (APDs). Most of QDs form in one APD area. However, a few QDs can be observed at the APD boundaries. Raman spectroscopy is used to probe the strain in GaAs layer. Slight redshift of both LO and TO GaAs peaks are observed when GaSb QDs are buried into GaAs matrix. Optical properties of capped QDs are characterized by photoluminescence measurement at low temperatures (20 K and 30 K). Emission peaks of GaSb/GaAs QDs are found in the range of 1.0-1.3 eV at both temperatures. Slight redshift is observed when the laser excitation power is increased at 20 K while blueshift of QD peak is observed at 30 K. We attribute this abnormal behavior to the contribution of overlapped GaSb wetting layer peak in the PL emission as well as the feature of type II band structure. [Figure not available: see fulltext.] © 2016, The Korean Institute of Metals and Materials and Springer Science+Business Media Dordrecht.},
note = {cited By 6},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We investigate structural Raman and photoluminescence properties of type II GaSb/GaAs quantum dots (QDs) grown on (001) Ge substrate by molecular beam epitaxy. Array of self-assembled GaSb QDs having an areal density of ∼1.66 × 1010 dots/cm2 is obtained by a growth at relatively low substrate temperature (450 °C) on a GaAs surface segmented into anti-phase domains (APDs). Most of QDs form in one APD area. However, a few QDs can be observed at the APD boundaries. Raman spectroscopy is used to probe the strain in GaAs layer. Slight redshift of both LO and TO GaAs peaks are observed when GaSb QDs are buried into GaAs matrix. Optical properties of capped QDs are characterized by photoluminescence measurement at low temperatures (20 K and 30 K). Emission peaks of GaSb/GaAs QDs are found in the range of 1.0-1.3 eV at both temperatures. Slight redshift is observed when the laser excitation power is increased at 20 K while blueshift of QD peak is observed at 30 K. We attribute this abnormal behavior to the contribution of overlapped GaSb wetting layer peak in the PL emission as well as the feature of type II band structure. [Figure not available: see fulltext.] © 2016, The Korean Institute of Metals and Materials and Springer Science+Business Media Dordrecht.
19.
Prongjit, P; Ratanathammaphan, S; Ha, N; Mano, T; Sakoda, K; Kuroda, T
Type-II recombination dynamics of tensile-strained GaP quantum dots in GaAs grown by droplet epitaxy Journal Article
In: Applied Physics Letters, vol. 109, no. 17, 2016, ISSN: 00036951, (cited By 3).
@article{Prongjit2016,
title = {Type-II recombination dynamics of tensile-strained GaP quantum dots in GaAs grown by droplet epitaxy},
author = {P Prongjit and S Ratanathammaphan and N Ha and T Mano and K Sakoda and T Kuroda},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84993950795&doi=10.1063%2f1.4965873&partnerID=40&md5=1d6b1c2d97ba0c64bdbfcc5df1b46bc8},
doi = {10.1063/1.4965873},
issn = {00036951},
year = {2016},
date = {2016-01-01},
journal = {Applied Physics Letters},
volume = {109},
number = {17},
publisher = {American Institute of Physics Inc.},
abstract = {We use droplet epitaxy to create tensile-strained GaP quantum dots in a GaAs matrix. A strong biaxial tensile strain leads to the formation of a type-II band lineup with a transition energy lower than the bulk GaAs band gap. The luminescence transients exhibit highly non-exponential decay behavior with an average time constant of 11 ± 2 μs, which is more than three orders of magnitude longer than the lifetime of standard type-I quantum dots. The prolonged luminescence decay time for the GaP/GaAs dots confirms the formation of the type-II band alignment associated with the tensile strain. © 2016 Author(s).},
note = {cited By 3},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We use droplet epitaxy to create tensile-strained GaP quantum dots in a GaAs matrix. A strong biaxial tensile strain leads to the formation of a type-II band lineup with a transition energy lower than the bulk GaAs band gap. The luminescence transients exhibit highly non-exponential decay behavior with an average time constant of 11 ± 2 μs, which is more than three orders of magnitude longer than the lifetime of standard type-I quantum dots. The prolonged luminescence decay time for the GaP/GaAs dots confirms the formation of the type-II band alignment associated with the tensile strain. © 2016 Author(s).
20.
Kunrugsa, M; Tung, K H P; Danner, A J; Panyakeow, S; Ratanathammaphan, S
Fabrication of GaSb quantum rings on GaAs(0 0 1) by droplet epitaxy Journal Article
In: Journal of Crystal Growth, vol. 425, pp. 287-290, 2015, ISSN: 00220248, (cited By 4).
@article{Kunrugsa2015,
title = {Fabrication of GaSb quantum rings on GaAs(0 0 1) by droplet epitaxy},
author = {M Kunrugsa and K H P Tung and A J Danner and S Panyakeow and S Ratanathammaphan},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84979958749&doi=10.1016%2fj.jcrysgro.2015.01.018&partnerID=40&md5=a6709989707cc3236fc2abd45315ca45},
doi = {10.1016/j.jcrysgro.2015.01.018},
issn = {00220248},
year = {2015},
date = {2015-01-01},
journal = {Journal of Crystal Growth},
volume = {425},
pages = {287-290},
publisher = {Elsevier B.V.},
abstract = {We report the achievement in the fabrication of self-assembled GaSb quantum rings (QRs) on GaAs(0 0 1) substrates by droplet epitaxy technique using molecular beam epitaxy. Surface morphology was characterized by atomic force microscopy. The QR formation can be described by the diffusion of Ga atoms out of an initial Ga droplet during crystallization with Sb flux. The understanding of the formation mechanism lights up the way to grow more complex GaSb nanostructures by droplet epitaxy. The optical properties of GaSb QRs in a GaAs matrix were investigated by photoluminescence (PL). Power- and temperature-dependent PL measurements were performed to study the carrier dynamics and to observe the characteristics of type-II band alignment. © 2015 Elsevier B.V. All rights reserved.},
note = {cited By 4},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We report the achievement in the fabrication of self-assembled GaSb quantum rings (QRs) on GaAs(0 0 1) substrates by droplet epitaxy technique using molecular beam epitaxy. Surface morphology was characterized by atomic force microscopy. The QR formation can be described by the diffusion of Ga atoms out of an initial Ga droplet during crystallization with Sb flux. The understanding of the formation mechanism lights up the way to grow more complex GaSb nanostructures by droplet epitaxy. The optical properties of GaSb QRs in a GaAs matrix were investigated by photoluminescence (PL). Power- and temperature-dependent PL measurements were performed to study the carrier dynamics and to observe the characteristics of type-II band alignment. © 2015 Elsevier B.V. All rights reserved.
21.
Khoklang, K; Kiravittaya, S; Kunrugsa, M; Prongjit, P; Thainoi, S; Ratanathammaphan, S; Panyakeow, S
Molecular beam epitaxial growth of GaSb quantum dots on (0 0 1) GaAs substrate with InGaAs insertion layer Journal Article
In: Journal of Crystal Growth, vol. 425, pp. 291-294, 2015, ISSN: 00220248, (cited By 3).
@article{Khoklang2015a,
title = {Molecular beam epitaxial growth of GaSb quantum dots on (0 0 1) GaAs substrate with InGaAs insertion layer},
author = {K Khoklang and S Kiravittaya and M Kunrugsa and P Prongjit and S Thainoi and S Ratanathammaphan and S Panyakeow},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84979959088&doi=10.1016%2fj.jcrysgro.2015.02.044&partnerID=40&md5=7cf71b7ba20245860fae84a168b8ec2e},
doi = {10.1016/j.jcrysgro.2015.02.044},
issn = {00220248},
year = {2015},
date = {2015-01-01},
journal = {Journal of Crystal Growth},
volume = {425},
pages = {291-294},
publisher = {Elsevier B.V.},
abstract = {We report on the molecular beam epitaxial growth of self-assembled GaSb quantum dots (QDs) on (0 0 1) GaAs substrates with an insertion layer. The insertion layer, which is a 4-monolayers (MLs) InxGa1-xAs (x=0.00, 0.07, 0.15, 0.20 and 0.25), is grown prior to the QD growth. With this InGaAs insertion layer, the obtained QD density decreases substantially, while the QD height and diameter increase as compared with typical GaSb QDs grown on conventional (0 0 1) GaAs surface under the same growth condition. The GaSb QDs on GaAs have the dome shape with elliptical base and the elongation direction of the base is along the [1 1 0] direction. When the InGaAs insertion layer is introduced, the distinct elongation disappears and the QD sidewall shows facet-related surfaces with (0 0 1) plateau on top. © 2015 Elsevier B.V. All rights reserved.},
note = {cited By 3},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We report on the molecular beam epitaxial growth of self-assembled GaSb quantum dots (QDs) on (0 0 1) GaAs substrates with an insertion layer. The insertion layer, which is a 4-monolayers (MLs) InxGa1-xAs (x=0.00, 0.07, 0.15, 0.20 and 0.25), is grown prior to the QD growth. With this InGaAs insertion layer, the obtained QD density decreases substantially, while the QD height and diameter increase as compared with typical GaSb QDs grown on conventional (0 0 1) GaAs surface under the same growth condition. The GaSb QDs on GaAs have the dome shape with elliptical base and the elongation direction of the base is along the [1 1 0] direction. When the InGaAs insertion layer is introduced, the distinct elongation disappears and the QD sidewall shows facet-related surfaces with (0 0 1) plateau on top. © 2015 Elsevier B.V. All rights reserved.
22.
Kunrugsa, M; Panyakeow, S; Ratanathammaphan, S
GaSb/GaAs quantum-ring-with-dot structures grown by droplet epitaxy Journal Article
In: Journal of Crystal Growth, vol. 416, pp. 73-77, 2015, ISSN: 00220248, (cited By 2).
@article{Kunrugsa2015a,
title = {GaSb/GaAs quantum-ring-with-dot structures grown by droplet epitaxy},
author = {M Kunrugsa and S Panyakeow and S Ratanathammaphan},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84922496126&doi=10.1016%2fj.jcrysgro.2015.01.026&partnerID=40&md5=dece11e0887f6cbe7be5fd652ebd29b9},
doi = {10.1016/j.jcrysgro.2015.01.026},
issn = {00220248},
year = {2015},
date = {2015-01-01},
journal = {Journal of Crystal Growth},
volume = {416},
pages = {73-77},
publisher = {Elsevier},
abstract = {We have studied the growth of GaSb/GaAs nanostructures by droplet epitaxy with the variation of Ga deposition temperature which is one of the key parameters. With the use of low Sb flux, GaSb quantum rings (QRs) were formed as a result of the outward diffusion of Ga atoms from the droplets during crystallization. An increase of the deposition temperature results in the larger QR size and the lower QR density due to the longer diffusion length of Ga atoms, which gives rise to the larger initial droplets. Interestingly, some portion of QR lobe breaks up and transforms into a quantum dot (QD) so as to reduce the mismatch strain. A nanostructure containing both QR and QD is called a quantum-ring-with-dot structure (QRDS). As the deposition temperature increases, the nanostructure height distribution changes from unimodal to bimodal behaviors owing to the significant difference between QR and QD heights, whereas the nanostructure diameter still exhibits a unimodal distribution. The bimodal height distribution strongly affects the optical properties and the dynamic of thermal-excited carriers. © 2015 Elsevier B.V. All rights reserved.},
note = {cited By 2},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We have studied the growth of GaSb/GaAs nanostructures by droplet epitaxy with the variation of Ga deposition temperature which is one of the key parameters. With the use of low Sb flux, GaSb quantum rings (QRs) were formed as a result of the outward diffusion of Ga atoms from the droplets during crystallization. An increase of the deposition temperature results in the larger QR size and the lower QR density due to the longer diffusion length of Ga atoms, which gives rise to the larger initial droplets. Interestingly, some portion of QR lobe breaks up and transforms into a quantum dot (QD) so as to reduce the mismatch strain. A nanostructure containing both QR and QD is called a quantum-ring-with-dot structure (QRDS). As the deposition temperature increases, the nanostructure height distribution changes from unimodal to bimodal behaviors owing to the significant difference between QR and QD heights, whereas the nanostructure diameter still exhibits a unimodal distribution. The bimodal height distribution strongly affects the optical properties and the dynamic of thermal-excited carriers. © 2015 Elsevier B.V. All rights reserved.
23.
Kunrugsa, M; Kiravittaya, S; Sopitpan, S; Ratanathammaphan, S; Panyakeow, S
Molecular beam epitaxial growth of GaSb/GaAs quantum dots on Ge substrates Journal Article
In: Journal of Crystal Growth, vol. 401, pp. 441-444, 2014, ISSN: 00220248, (cited By 12).
@article{Kunrugsa2014,
title = {Molecular beam epitaxial growth of GaSb/GaAs quantum dots on Ge substrates},
author = {M Kunrugsa and S Kiravittaya and S Sopitpan and S Ratanathammaphan and S Panyakeow},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84906958887&doi=10.1016%2fj.jcrysgro.2014.02.048&partnerID=40&md5=8e717ba4bf17866659316fe19a1a3fcd},
doi = {10.1016/j.jcrysgro.2014.02.048},
issn = {00220248},
year = {2014},
date = {2014-01-01},
journal = {Journal of Crystal Growth},
volume = {401},
pages = {441-444},
publisher = {Elsevier B.V.},
abstract = {We perform structural and optical investigations of GaSb/GaAs quantum dots (QDs) grown on Ge (001) substrates by molecular beam epitaxy. Anti-phase domains (APDs) of GaAs are distributed on Ge substrate after the growth of GaAs due to the growth nature of III-V compound on group IV semiconductors having polar and non-polar behaviors. The APDs affect the QD growth as demonstrated by the growth of conventional InAs QDs on this surface. For GaSb QDs, the GaSb layer is grown on GaAs APD surface and compared with the GaSb layer on conventional (001) GaAs surface. Self-assembled QDs are formed on both surfaces but structural analysis reveals evidence of shape and size differences, which is attributed to the influence of the initial surface. Photoluminescence of GaSb/GaAs QDs grown on both Ge and GaAs substrates is studied. Emission from GaSb/GaAs QDs on Ge substrate can be detected till near room temperature (270 K). © 2014 Elsevier B.V.},
note = {cited By 12},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We perform structural and optical investigations of GaSb/GaAs quantum dots (QDs) grown on Ge (001) substrates by molecular beam epitaxy. Anti-phase domains (APDs) of GaAs are distributed on Ge substrate after the growth of GaAs due to the growth nature of III-V compound on group IV semiconductors having polar and non-polar behaviors. The APDs affect the QD growth as demonstrated by the growth of conventional InAs QDs on this surface. For GaSb QDs, the GaSb layer is grown on GaAs APD surface and compared with the GaSb layer on conventional (001) GaAs surface. Self-assembled QDs are formed on both surfaces but structural analysis reveals evidence of shape and size differences, which is attributed to the influence of the initial surface. Photoluminescence of GaSb/GaAs QDs grown on both Ge and GaAs substrates is studied. Emission from GaSb/GaAs QDs on Ge substrate can be detected till near room temperature (270 K). © 2014 Elsevier B.V.
24.
Kunrugsa, M; Kiravittaya, S; Panyakeow, S; Ratanathammaphan, S
Effect of Ga deposition rates on GaSb nanostructures grown by droplet epitaxy Journal Article
In: Journal of Crystal Growth, vol. 402, pp. 285-290, 2014, ISSN: 00220248, (cited By 6).
@article{Kunrugsa2014a,
title = {Effect of Ga deposition rates on GaSb nanostructures grown by droplet epitaxy},
author = {M Kunrugsa and S Kiravittaya and S Panyakeow and S Ratanathammaphan},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84917689862&doi=10.1016%2fj.jcrysgro.2014.06.036&partnerID=40&md5=582d93300d0ea83a9c3bca6e16e0218d},
doi = {10.1016/j.jcrysgro.2014.06.036},
issn = {00220248},
year = {2014},
date = {2014-01-01},
journal = {Journal of Crystal Growth},
volume = {402},
pages = {285-290},
publisher = {Elsevier},
abstract = {We investigate the effect of Ga deposition rates on GaSb nanostructures grown by droplet epitaxy on GaAs (001) substrates. Ga deposition rate was varied to form the different size and density of Ga droplets. After the droplets were exposed to Sb flux, not only the GaSb ring structure but also the complex nanostructure like the GaSb ring structure surrounded by ring-shaped dot molecules were obtained. A simple descriptive model is proposed to describe formation mechanisms of these nanostructures. It is found that Ga droplet size, distance between Ga droplets and diffusion area of Ga atoms during crystallization with Sb flux are all the crucial factors which determine the shape of GaSb nanostructures. Due to a lattice mismatch between GaSb and GaAs, strain occurred during a crystallization process should also be taken into account. Photoluminescence was carried out to verify our model. © 2014 Elsevier B.V.},
note = {cited By 6},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We investigate the effect of Ga deposition rates on GaSb nanostructures grown by droplet epitaxy on GaAs (001) substrates. Ga deposition rate was varied to form the different size and density of Ga droplets. After the droplets were exposed to Sb flux, not only the GaSb ring structure but also the complex nanostructure like the GaSb ring structure surrounded by ring-shaped dot molecules were obtained. A simple descriptive model is proposed to describe formation mechanisms of these nanostructures. It is found that Ga droplet size, distance between Ga droplets and diffusion area of Ga atoms during crystallization with Sb flux are all the crucial factors which determine the shape of GaSb nanostructures. Due to a lattice mismatch between GaSb and GaAs, strain occurred during a crystallization process should also be taken into account. Photoluminescence was carried out to verify our model. © 2014 Elsevier B.V.
25.
Tubchareon, T; Soisuwan, S; Ratanathammaphan, S; Praserthdam, P
Effect of Na content on the physical properties of Ba0.5Sr0.5TiO3 powders Journal Article
In: Advances in Materials Science and Engineering, vol. 2014, 2014, ISSN: 16878434, (cited By 4).
@article{Tubchareon2014,
title = {Effect of Na content on the physical properties of Ba0.5Sr0.5TiO3 powders},
author = {T Tubchareon and S Soisuwan and S Ratanathammaphan and P Praserthdam},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84894805018&doi=10.1155%2f2014%2f602504&partnerID=40&md5=336ac0e3b4adc9f8341f81b33c4845a0},
doi = {10.1155/2014/602504},
issn = {16878434},
year = {2014},
date = {2014-01-01},
journal = {Advances in Materials Science and Engineering},
volume = {2014},
abstract = {The different Na contents (0 ≤ Na ≤ 0.35, based on mole of NaOH) of doped Ba0.5Sr0.5TiO3 (BST) powders synthesized via sol-gel process were studied. The substitution of Na+ ions into a partial A-site of BST powders provided the reduction in vacancy defects as confirmed by electron paramagnetic resonance (EPR) and UV-visible spectroscopy. Photoluminescence (PL) spectra appeared in violet, blue, and green emissions. The phase structure, oxygen deficiency, and titanium deficiency of BST powders were further investigated as a function of Na content. X-ray diffraction (XRD) result was found that low Na content (0 ≤ Na ≤ 0.15) exhibited the tetragonal structure, while it was transformed to the cubic phase when high Na content. Moreover, X-ray photoelectron spectroscopy (XPS) result revealed that the partial oxidation of Ti3+ ions to Ti4+ ions was observed at Na content lower than 0.05 mole, while more addition of Na content resulted in the increasing of the oxygen and the titanium deficiency. Furthermore, the result indicated the oxygen deficiency significantly formed at the A-site of Sr atoms more than that of Ba atoms. © 2014 Tassanee Tubchareon et al.},
note = {cited By 4},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The different Na contents (0 ≤ Na ≤ 0.35, based on mole of NaOH) of doped Ba0.5Sr0.5TiO3 (BST) powders synthesized via sol-gel process were studied. The substitution of Na+ ions into a partial A-site of BST powders provided the reduction in vacancy defects as confirmed by electron paramagnetic resonance (EPR) and UV-visible spectroscopy. Photoluminescence (PL) spectra appeared in violet, blue, and green emissions. The phase structure, oxygen deficiency, and titanium deficiency of BST powders were further investigated as a function of Na content. X-ray diffraction (XRD) result was found that low Na content (0 ≤ Na ≤ 0.15) exhibited the tetragonal structure, while it was transformed to the cubic phase when high Na content. Moreover, X-ray photoelectron spectroscopy (XPS) result revealed that the partial oxidation of Ti3+ ions to Ti4+ ions was observed at Na content lower than 0.05 mole, while more addition of Na content resulted in the increasing of the oxygen and the titanium deficiency. Furthermore, the result indicated the oxygen deficiency significantly formed at the A-site of Sr atoms more than that of Ba atoms. © 2014 Tassanee Tubchareon et al.