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
Tubchareon, T; Soisuwan, S; Ratanathammaphan, S; Praserthdam, P
Effect of carbon-dopant on the optical band gap and photoluminescence properties of [Ba0.5Sr0.5]TiO3 powders synthesized by the sol-gel process Journal Article
In: Journal of Luminescence, vol. 145, pp. 919-924, 2014, ISSN: 00222313, (cited By 4).
@article{Tubchareon2014a,
title = {Effect of carbon-dopant on the optical band gap and photoluminescence properties of [Ba0.5Sr0.5]TiO3 powders synthesized by the sol-gel process},
author = {T Tubchareon and S Soisuwan and S Ratanathammaphan and P Praserthdam},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84885137600&doi=10.1016%2fj.jlumin.2013.09.017&partnerID=40&md5=657cd291f3385f1e2ae46b028df36977},
doi = {10.1016/j.jlumin.2013.09.017},
issn = {00222313},
year = {2014},
date = {2014-01-01},
journal = {Journal of Luminescence},
volume = {145},
pages = {919-924},
abstract = {In this paper we studied the effect of carbon-doped on the optical band gap and photoluminescence properties of barium strontium titanate powders, [Ba 0.5Sr0.5]TiO3 (BST), that synthesized via the sol-gel process with internal carbon sources, i.e., methanol, ethanol, and 1-butanol acting as a solvent. The types of solvent governed on the in-gap mechanism of C-doped BST powders. The Ti4+ ions substitution with partial C4+ ions was clearly proved by Fourier transform infrared spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy (XPS). As-synthesized pure BST powders were less weight losses and the carbonate species not observed. Indirect band gap of BST powders was examined by ultraviolet-visible spectroscopy. A possible in-gap mechanism between valence band maximum and conduction band minimum of BST powders was investigated by photoluminescence (PL) behavior. The PL emissions of pure BST powders appeared in five processes at 3.15, 2.95, 2.80, 2.55 and 2.33 eV, whereas the C-doped BST powder did not appear at 2.95 eV. Since the strong interaction of C-O bonds appeared that have been shared electrons of OåCåO bonds rather than transferred in the octahedral [TiO6] clusters. XPS and electron paramagnetic resonance spectra revealed the amount of oxygen deficiency was considerably formed by the long chain alcohol, while the short chain alcohol exhibited low amount. Besides that, (Ba+Sr)/Ti and (TiO5-V OX)/(TiO6) ratio increased gradually as molecular weight of alcohol. © 2013 Published by Elsevier B.V.},
note = {cited By 4},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Prongjit, P; Pankaow, N; Boonpeng, P; Thainoi, S; Panyakeow, S; Ratanathammaphan, S
Tensile strained, type II, GaP/GaAs nanostructures Journal Article
In: Chiang Mai Journal of Science, vol. 40, no. 6 SPEC. ISSUE 2, pp. 957-962, 2013, ISSN: 01252526, (cited By 0).
@article{Prongjit2013,
title = {Tensile strained, type II, GaP/GaAs nanostructures},
author = {P Prongjit and N Pankaow and P Boonpeng and S Thainoi and S Panyakeow and S Ratanathammaphan},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84893497859&partnerID=40&md5=8a0a20a803ec1a1dcc4da7319eee129c},
issn = {01252526},
year = {2013},
date = {2013-01-01},
journal = {Chiang Mai Journal of Science},
volume = {40},
number = {6 SPEC. ISSUE 2},
pages = {957-962},
abstract = {We demonstrate the fabrication of self-assembled GaP nanostructures on GaAs (100) substrates by droplet epitaxy using molecular beam epitaxy. The dependency of GaP nanostructural properties on substrate temperature (250-350°C) as droplets are deposited is investigated. The dimension, density, and shape of GaP nanostructures strongly depend on the substrate temperature. It is found that nano-dots are formed when Ga droplets are deposited at 250°C, while ring-shape nanostructures are formed when Ga droplets are deposited at 300°C or higher. Photoluminescence results confirm the high quality of the GaP nanocrystals.},
note = {cited By 0},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Han, S S; Higo, A; Yunpeng, W; Deura, M; Sugiyama, M; Nakano, Y; Panyakeow, S; Ratanathammaphan, S
In: Microelectronic Engineering, vol. 112, pp. 143-148, 2013, ISSN: 01679317, (cited By 1).
@article{Han2013,
title = {Effect of GaP and GaP/InGaP insertion layers on the structural and optical properties of InP quantum dots grown by metal-organic vapor phase epitaxy},
author = {S S Han and A Higo and W Yunpeng and M Deura and M Sugiyama and Y Nakano and S Panyakeow and S Ratanathammaphan},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84884704307&doi=10.1016%2fj.mee.2013.01.026&partnerID=40&md5=817d6484f0e53058753d4b9f02045640},
doi = {10.1016/j.mee.2013.01.026},
issn = {01679317},
year = {2013},
date = {2013-01-01},
journal = {Microelectronic Engineering},
volume = {112},
pages = {143-148},
abstract = {A comparison of ultra-thin insertion layers (GaP and GaP/In 0.4Ga0.6P) on InP self-assembled quantum dots (SAQDs) grown on GaAs (0 0 1) substrates using metal-organic vapor phase epitaxy (MOVPE) was studied. Atomic force microscopy (AFM) and photoluminescence (PL) were employed to characterize the optical and structural properties of the grown InP QDs. It is found that the QD dimension, size distribution and density strongly depend on the insertion layer thickness which led to tune the emission wavelength and narrowing of full width at half maximum (FWHM) at low temperature (20-250 K) and at room-temperature PL measurements. This result is attributed to the improved QD size and quantum confinement effect arising from the insertion of the GaP and GaP/In0.4Ga0.6P layers. © 2013 Elsevier B.V. All rights reserved.},
note = {cited By 1},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Boonpeng, P; Kiravittaya, S; Thainoi, S; Panyakeow, S; Ratanathammaphan, S
InGaAs quantum-dot-in-ring structure by droplet epitaxy Journal Article
In: Journal of Crystal Growth, vol. 378, pp. 435-438, 2013, ISSN: 00220248, (cited By 11).
@article{Boonpeng2013,
title = {InGaAs quantum-dot-in-ring structure by droplet epitaxy},
author = {P Boonpeng and S Kiravittaya and S Thainoi and S Panyakeow and S Ratanathammaphan},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84885431768&doi=10.1016%2fj.jcrysgro.2012.12.056&partnerID=40&md5=626557246136c6375e9161a6971f0994},
doi = {10.1016/j.jcrysgro.2012.12.056},
issn = {00220248},
year = {2013},
date = {2013-01-01},
journal = {Journal of Crystal Growth},
volume = {378},
pages = {435-438},
publisher = {Elsevier B.V.},
abstract = {The controlled fabrication of self-assembled InGaAs nanostructures i.e., quantum ring (QR) and quantum-dot-in-ring (QDIR) by droplet epitaxy is reported. The effects of crystallization temperature (170-260 1°C) on the nanostructure shape, dimension, density, and depth profile are investigated. The QRs transform to QDIRs when the crystallization temperature is increased. At transformation state, the QRs with distorted nanohole profile along the [1-10] crystallographic direction are observed. The formation mechanism can be explained by the competitive crystallizations in and around the nanodroplet and strain relaxation in the nanohole. © 2013 Elsevier B.V. All rights reserved.},
note = {cited By 11},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Pankaow, N; Prongjit, P; Thainoi, S; Panyakeow, S; Ratanathammaphan, S
Ring-to-dots transformation of InGaAs quantum rings grown by droplet epitaxy Journal Article
In: Microelectronic Engineering, vol. 110, pp. 298-301, 2013, ISSN: 01679317, (cited By 2).
@article{Pankaow2013,
title = {Ring-to-dots transformation of InGaAs quantum rings grown by droplet epitaxy},
author = {N Pankaow and P Prongjit and S Thainoi and S Panyakeow and S Ratanathammaphan},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84885191160&doi=10.1016%2fj.mee.2013.02.029&partnerID=40&md5=a3b34ba727f05a7a30e396f82dd79ab2},
doi = {10.1016/j.mee.2013.02.029},
issn = {01679317},
year = {2013},
date = {2013-01-01},
journal = {Microelectronic Engineering},
volume = {110},
pages = {298-301},
publisher = {Elsevier B.V.},
abstract = {Post-growth annealing in UHV can lead to the deformation of crystallized nanostructures. Annealing effects on structural and optical properties of InGaAs quantum rings (QRs) grown by droplet epitaxy was examined. The InGaAs QRs were fabricated by depositing 3 monolayer (ML) of In0.5Ga0.5 on GaAs (100) at the substrate temperature of 140°C, and crystallized in As4 flux of∼7×10-6 Torr at 180°C for 5 min. After the crystallization, the substrate temperature was ramped up to the desired annealing temperature (Ta) of 300-400°C in As4 beam. In situ transformations of surface morphology were observed upon the evolution of RHEED patterns. Surface morphology was analyzed by AFM. As ramping up the annealing temperature, the QRs deformed and changed to numerous smaller QDs about the QR positions. Supposedly, there was segregation of group III atoms out of the QRs. At 380°C, the QRs properly lost their actual shapes and burst into high-density small QDs. Most possible reasons of the segregation can be crystalline instability of the low-temperature-crystallized QRs, along with the different surface kinetics of In and Ga atoms. © 2013 Elsevier B.V. All rights reserved.},
note = {cited By 2},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Tubchareon, T; Soisuwan, S; Ratanathammaphan, S; Praserthdam, P
Effect of Na-, K-, Mg-, and Ga dopants in A/B-sites on the optical band gap and photoluminescence behavior of [Ba0.5Sr0.5]TiO 3 powders Journal Article
In: Journal of Luminescence, vol. 142, pp. 75-80, 2013, ISSN: 00222313, (cited By 24).
@article{Tubchareon2013,
title = {Effect of Na-, K-, Mg-, and Ga dopants in A/B-sites on the optical band gap and photoluminescence behavior of [Ba0.5Sr0.5]TiO 3 powders},
author = {T Tubchareon and S Soisuwan and S Ratanathammaphan and P Praserthdam},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84877746619&doi=10.1016%2fj.jlumin.2013.03.040&partnerID=40&md5=6b22ed52abb0027ea660fce919717f5b},
doi = {10.1016/j.jlumin.2013.03.040},
issn = {00222313},
year = {2013},
date = {2013-01-01},
journal = {Journal of Luminescence},
volume = {142},
pages = {75-80},
abstract = {In this work, the role of the representative metal dopants (Na, K, Mg and Ga) in A/B-sites of [Ba0.5Sr0.5]TiO3 powders (in short BST) synthesized by sol-gel method have been investigated. As revealed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV-visible spectroscopy, Na and K can be occupied into A-site, while Mg and Ga can be substituted on B-site of BST powders. It was found that the optical band gap energies of modified B-site are higher than modified A-site of BST powders. The possible mechanisms of intermediate energy levels between optical band gaps were suggested by photoluminescence (PL) behavior. The four major optical emissions in visible range were found to be 2.95, 2.80, 2.55, and 2.33 eV. The 2.95 eV in violet PL emissions is related to the electron transfer in octahedral [TiO6] clusters. Moreover, this energy level is attributed to the charge compensation process due to acceptor substitution defects in order to preserve the overall charge neutrality in the BST crystal. The 2.85 eV in blue PL emissions is attributed to the fully-ionized oxygen vacancy (V O••) in BST powders. The 2.55 and 2.33 eV in green PL emission are assigned to the charge-transfer of singly-ionized oxygen vacancy (VO•) and the charge transfer vibronic excitons (CTVE) in BST perovskite, respectively. In additional, as revealed by electron paramagnetic resonance (EPR), modified B-site of BST powders facilitated titanium vacancy more than modified A-site. The X-ray photoelectron spectroscopy (XPS) results indicated that modified B-site of BST powders were easily created oxygen deficiency than modified A-site. However, the oxygen deficiency significantly affected on A-site of the Sr atoms site more than A-site of the Ba atoms, it might be a result of the strength of chemical bond of Sr-O bonds which is lower than Ba-O bonds. © 2013 Published by Elsevier B.V. All rights reserved.},
note = {cited By 24},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Han, S S; Panyakeow, S; Ratanathammaphan, S; Higo, A; Yunpeng, W; Deura, M; Sugiyama, M; Nakano, Y
The effect of thin gap insertion layer on InP nanostructure grown by metal-organic vapour phase epitaxys Journal Article
In: Canadian Journal of Chemical Engineering, vol. 90, no. 4, pp. 915-918, 2012, ISSN: 00084034, (cited By 0).
@article{Han2012,
title = {The effect of thin gap insertion layer on InP nanostructure grown by metal-organic vapour phase epitaxys},
author = {S S Han and S Panyakeow and S Ratanathammaphan and A Higo and W Yunpeng and M Deura and M Sugiyama and Y Nakano},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84863538558&doi=10.1002%2fcjce.21648&partnerID=40&md5=7b4fdb2489318892cd05cfe9f5f0a66f},
doi = {10.1002/cjce.21648},
issn = {00084034},
year = {2012},
date = {2012-01-01},
journal = {Canadian Journal of Chemical Engineering},
volume = {90},
number = {4},
pages = {915-918},
abstract = {The effect of thin GaP insertion layers on the structural and optical properties of InP/In 0.49Ga 0.51P self-assembled quantum dots (SAQDs) on GaAs (001) substrate grown by metal-organic vapour phase epitaxy has been reported. The properties of InP/In 0.49Ga 0.51P SAQDs are modified when a thin (1-4 ML) GaP layer is inserted underneath the InP quantum dots (QDs). Deposition of the GaP insertion layer affects the dot dimension and improves the size uniformity. The density, dimension and uniformity of InP QDs strongly depend on the GaP insertion layer thickness. This variation in QD size is a result of a material nucleation effect caused by atomic intermixing between the InP QDs and underlying GaP insertion layer and surface energy. The insertion of GaP layer led to tuning the emission wavelength and narrowing of full width at half maximum (FWHM) when they are characterised by PL measurements at room temperature. © 2012 Canadian Society for Chemical Engineering.},
note = {cited By 0},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Tangmettajittakul, O -A; Thainoi, S; Panyakeow, S; Ratanathammaphan, S
Evolution of self-assembled InAs quantum dot molecules by molecular beam epitaxy Journal Article
In: Physica Status Solidi (C) Current Topics in Solid State Physics, vol. 9, no. 7, pp. 1534-1536, 2012, ISSN: 18626351, (cited By 1).
@article{Tangmettajittakul2012,
title = {Evolution of self-assembled InAs quantum dot molecules by molecular beam epitaxy},
author = {O -A Tangmettajittakul and S Thainoi and S Panyakeow and S Ratanathammaphan},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84864019137&doi=10.1002%2fpssc.201100620&partnerID=40&md5=74161472a731b022276f75c6a81fe121},
doi = {10.1002/pssc.201100620},
issn = {18626351},
year = {2012},
date = {2012-01-01},
journal = {Physica Status Solidi (C) Current Topics in Solid State Physics},
volume = {9},
number = {7},
pages = {1534-1536},
abstract = {Self-assembled InAs quantum dot molecules (QDMs) have been grown by thin-capping-and-regrowth MBE technique. The QDM-forming conditions have been changed by varying InAs growth rate in the range of 0.01-0.03 ML/s. We found that the InAs growth rate affects nano-propeller shape, dot density, and dot height. The densities of QDs, nano-propellers, and QDMs are increasing while increasing the InAs growth rate. In contrast, the dot height and the length of propeller blades are contrary to growth rate. Also, the uniformity of dots in QDMs can be changed by an increase of growth rate. These results are confirmed by photoluminescence (PL) measurement. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.},
note = {cited By 1},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Prongjit, P; Pankaow, N; Thainoi, S; Panyakeow, S; Ratanathammaphan, S
Formation of GaP nanostructures on GaAs (100) by droplet molecular beam epitaxy Journal Article
In: Physica Status Solidi (C) Current Topics in Solid State Physics, vol. 9, no. 7, pp. 1540-1542, 2012, ISSN: 18626351, (cited By 4).
@article{Prongjit2012,
title = {Formation of GaP nanostructures on GaAs (100) by droplet molecular beam epitaxy},
author = {P Prongjit and N Pankaow and S Thainoi and S Panyakeow and S Ratanathammaphan},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84864021442&doi=10.1002%2fpssc.201100798&partnerID=40&md5=048297d24f58e66f74f0493f263b3555},
doi = {10.1002/pssc.201100798},
issn = {18626351},
year = {2012},
date = {2012-01-01},
journal = {Physica Status Solidi (C) Current Topics in Solid State Physics},
volume = {9},
number = {7},
pages = {1540-1542},
abstract = {In this contribution, we have demonstrated the fabrication of tensile strained GaP nanostructures on GaAs (100) substrates by droplet epitaxy using molecular beam epitaxy. The GaP nanostructures are ring-like structure due to crystallization with low P 2 pressure. The density of GaP ring-like nanostructures varies between 8.92×10 8-2.17×10 9 cm -2 and the average of diameter varies between 88.4-133 nm with increasing the Ga amount deposition in the range of 2.4-4.8 ML. The photoluminescence result shows the tensile strain-modified band gap effect of GaP nanostructure in GaAs matrix and it also confirms the high-quality of GaP nanocrystal. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.},
note = {cited By 4},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Pankaow, N; Thainoi, S; Panyakeow, S; Ratanathammaphan, S
Surface morphology and photoluminescence of InGaAs quantum rings grown by droplet epitaxy with varying In0.5Ga0.5 droplet amount Journal Article
In: Journal of Crystal Growth, vol. 323, no. 1, pp. 282-285, 2011, ISSN: 00220248, (cited By 7).
@article{Pankaow2011a,
title = {Surface morphology and photoluminescence of InGaAs quantum rings grown by droplet epitaxy with varying In0.5Ga0.5 droplet amount},
author = {N Pankaow and S Thainoi and S Panyakeow and S Ratanathammaphan},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-79957981518&doi=10.1016%2fj.jcrysgro.2010.10.129&partnerID=40&md5=18d7b05133f3bdc84f729b941bfbe281},
doi = {10.1016/j.jcrysgro.2010.10.129},
issn = {00220248},
year = {2011},
date = {2011-01-01},
journal = {Journal of Crystal Growth},
volume = {323},
number = {1},
pages = {282-285},
abstract = {We have presented the study result of physical and optical properties of the InGaAs quantum ring (QR) structures grown by droplet epitaxy using molecular beam epixaty. The structural properties and quality of QRs strongly depended on In0.5Ga0.5 droplet amount. The photoluminescence (PL) results confirmed the crystal quality of the nanocrystal of the capped samples with the optimum In0.5Ga0.5 droplet amount. The optimum In0.5Ga0.5 amount is 3 and 4 ML (monolayer) under the droplet forming condition of 210°C substrate and crystallization at 180°C. The PL measuring parameters, including excitation intensity and polarization, have been varied. The polarized PL spectra indicated anisotropy in the QR structures. © 2010 Elsevier B.V. All rights reserved.},
note = {cited By 7},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Jevasuwan, W; Boonpeng, P; Thainoi, S; Panyakeow, S; Ratanathammaphan, S
InP ring-shaped quantum-dot molecules grown by droplet molecular beam epitaxy Journal Article
In: Journal of Crystal Growth, vol. 323, no. 1, pp. 275-278, 2011, ISSN: 00220248, (cited By 7).
@article{Jevasuwan2011,
title = {InP ring-shaped quantum-dot molecules grown by droplet molecular beam epitaxy},
author = {W Jevasuwan and P Boonpeng and S Thainoi and S Panyakeow and S Ratanathammaphan},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-79958002371&doi=10.1016%2fj.jcrysgro.2010.11.135&partnerID=40&md5=50b266c6eb2083055e155f39441d86ac},
doi = {10.1016/j.jcrysgro.2010.11.135},
issn = {00220248},
year = {2011},
date = {2011-01-01},
journal = {Journal of Crystal Growth},
volume = {323},
number = {1},
pages = {275-278},
abstract = {In this paper, the reflection high energy electron diffraction of the transition from a two-dimensional growth mode to a three-dimensional growth mode of InP ring-shaped quantum-dot molecule (QDM) formation in the matrices of In0.5Ga0.5P on semi-insulating GaAs(0 0 1) substrates was reported. All samples were grown by solid-source molecular beam epitaxy using the droplet epitaxy technique under different crystallization temperature conditions. The surface morphologies of InP ring-shaped QDMs were examined by atomic force microscopy and the photoluminescence (PL) spectra were obtained by the 478 nm line of an Ar laser with an InGaAs detector. The dependence of the PL ground-state peak energies as the function of power and temperature with the tendencies of PL peak and full width at half maximum were investigated and discussed. © 2010 Elsevier B.V. All rights reserved.},
note = {cited By 7},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Boonpeng, P; Jevasuwan, W; Nuntawong, N; Thainoi, S; Panyakeow, S; Ratanathammaphan, S
Transformation of concentric quantum double rings to single quantum rings with squarelike nanoholes on GaAs(0 0 1) by droplet epitaxy Journal Article
In: Journal of Crystal Growth, vol. 323, no. 1, pp. 271-274, 2011, ISSN: 00220248, (cited By 4).
@article{Boonpeng2011,
title = {Transformation of concentric quantum double rings to single quantum rings with squarelike nanoholes on GaAs(0 0 1) by droplet epitaxy},
author = {P Boonpeng and W Jevasuwan and N Nuntawong and S Thainoi and S Panyakeow and S Ratanathammaphan},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-79957985814&doi=10.1016%2fj.jcrysgro.2010.12.034&partnerID=40&md5=0313280f95279ff610a5b4f02f431f17},
doi = {10.1016/j.jcrysgro.2010.12.034},
issn = {00220248},
year = {2011},
date = {2011-01-01},
journal = {Journal of Crystal Growth},
volume = {323},
number = {1},
pages = {271-274},
abstract = {The fabrication of self-assembled InxGa1-xAs nanostructures on GaAs(0 0 1) substrates grown by droplet epitaxy using molecular beam epitaxy is reported. The effect of In contents (0≤x≤0.2) for InxGa1-x droplets on their shape, dimension, density, and depth profile was investigated. The concentric quantum double rings (CQDRs) are transformed into quantum rings (QRs) with squarelike nanoholes when In content is increased. The transformation mechanism is explained by the strain relaxation arguments. As In content increases, crystallization can occur not only from the outer periphery, but also from the inner periphery of the rings. This is confirmed by decrease in outer dimension and change in the hole profile along the [1 -1 0] direction. In addition, low density QRs with shallow nanoholes were found on the surface for In content of 0.2. The surface morphology of InxGa1-xAs nanostructures was examined by atomic force microscopy (AFM). © 2010 Elsevier B.V. All rights reserved.},
note = {cited By 4},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Jevasuwan, W; Boonpeng, P; Panyakeow, S; Ratanathammaphan, S
Growth and characterization of InP ringlike quantum-dot molecules grown by solid-source molecular beam epitaxy Journal Article
In: Journal of Nanoscience and Nanotechnology, vol. 10, no. 11, pp. 7291-7294, 2010, ISSN: 15334880, (cited By 2).
@article{Jevasuwan2010,
title = {Growth and characterization of InP ringlike quantum-dot molecules grown by solid-source molecular beam epitaxy},
author = {W Jevasuwan and P Boonpeng and S Panyakeow and S Ratanathammaphan},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-79955539061&doi=10.1166%2fjnn.2010.2860&partnerID=40&md5=74402e6521930ab80bbfa80da60ce780},
doi = {10.1166/jnn.2010.2860},
issn = {15334880},
year = {2010},
date = {2010-01-01},
journal = {Journal of Nanoscience and Nanotechnology},
volume = {10},
number = {11},
pages = {7291-7294},
abstract = {In this paper, we have studied the fabrication of lnP ringlike quantum-dot molecules on GaAs(001) substrate grown by solid-source molecular beam epitaxy using droplet epitaxy technique and the effect of In deposition rate on the physical and optical properties of lnP ringlike quantum-dot molecules. The In deposition rate is varied from 0.2 MLJs to 0.4, 0.8 and 1.6 MLJ5. The surface morphology and cross-section were examined by ox-situ atomic force microscope and transmission electron microscope, respectively. The increasing of In deposition rate results in the decreasing of outer and inner diameters of lnP ringlike quantum-dot molecules and height of lnP quantum dots but increases the InP quantum dot and ringlike quantum-dot molecule densities. The photoluminescence peaks of lnP ringlike quantum-dot molecules are blue-shifted and FWHM is narrower when In deposition rate is bigger. Copyright © 2010 American Scientific Publishers.},
note = {cited By 2},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Boonpeng, P; Jevasuwan, W; Panyakeow, S; Ratanathammaphan, S
Fabrication of self-assembled InGaAs squarelike nanoholes on GaAs(001) by droplet epitaxy Journal Article
In: Japanese Journal of Applied Physics, vol. 49, no. 4 PART 2, 2010, ISSN: 00214922, (cited By 3).
@article{Boonpeng2010,
title = {Fabrication of self-assembled InGaAs squarelike nanoholes on GaAs(001) by droplet epitaxy},
author = {P Boonpeng and W Jevasuwan and S Panyakeow and S Ratanathammaphan},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-77952738153&doi=10.1143%2fJJAP.49.04DH09&partnerID=40&md5=711c47bed53f01d59b03ceff8ebed1b1},
doi = {10.1143/JJAP.49.04DH09},
issn = {00214922},
year = {2010},
date = {2010-01-01},
journal = {Japanese Journal of Applied Physics},
volume = {49},
number = {4 PART 2},
abstract = {The fabrication of self-assembled InGaAs squarelike nanoholes on GaAs(001) substrates grown by droplet epitaxy using molecular beam epitaxy was reported. The formation mechanism is explained by the As4 diffusion in droplets during the supply of As4 flux. The effects of substrate temperature (300-390 °C) during the InGa droplet deposition on their dimension and density were investigated. The surface morphology of InGaAs nanoholes as well as their depth profile was examined by atomic force microscopy (AFM). The square shape is oriented along [110] and [1̄10] crystallographic directions with slightly different profiles due to anisotropy behavior. The size uniformity of the squarelike nanoholes is well controlled with less deviation at higher substrate temperatures. © 2010 The Japan Society of Applied Physics.},
note = {cited By 3},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Boonpeng, P; Jevasuwan, W; Suraprapapich, S; Ratanathammaphan, S; Panyakeow, S
Quadra-quantum dots grown on quantum rings having square-shaped holes: Basic nanostructure for quantum dot cellular automata application Journal Article
In: Microelectronic Engineering, vol. 86, no. 4-6, pp. 853-856, 2009, ISSN: 01679317, (cited By 17).
@article{Boonpeng2009,
title = {Quadra-quantum dots grown on quantum rings having square-shaped holes: Basic nanostructure for quantum dot cellular automata application},
author = {P Boonpeng and W Jevasuwan and S Suraprapapich and S Ratanathammaphan and S Panyakeow},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-67349259320&doi=10.1016%2fj.mee.2008.12.027&partnerID=40&md5=5af843ea904d45a2c0381ce0a9abc543},
doi = {10.1016/j.mee.2008.12.027},
issn = {01679317},
year = {2009},
date = {2009-01-01},
journal = {Microelectronic Engineering},
volume = {86},
number = {4-6},
pages = {853-856},
abstract = {Preferable quantum dot (QD) nanostructure for quantum computation based on quantum cellular automata (QCA) is laterally close-packed quantum dot molecular (QDM) having 4 QDs at the corners of square configuration. We called this 4 QDs-set as quadra-quantum dots (QQDs). Aligned QQDs with 2 electron-confinements work like a wire for digital information transmission by Coulomb repulsion force which is high speed and consumes little power. Combination of QQDs in line and their cross-over work as logic gates and memory bits. We have developed a Molecular Beam Epitaxial (MBE) growth technique call "Droplet Epitaxy" for several quantum nanostructures such as quantum rings (QRs), quantum dot rings (QDRs). In this presentation, we prepare QRs with 20 ML In-Ga (15:85) droplet at 390 °C and droplet growth rate of 1ML/s. Arsenic flux (7-8 × 10-6 Torr) is then exposed for InGaAs crystallization at 200 °C for 5 min. During droplet epitaxy at high value of droplet thickness and high temperature, out-diffusion from the centre of droplets occurs under anisotropic stain. This leads to quantum ring structures having non-uniform ring stripes and deep square-shaped nanoholes. Using these peculiar QRs as templates, 4 QDs situating at each corner of square shape are regrown. Two of these 4 QDs are aligned either [1over(1, ̄) 0] or [1 1 0] which are preferable crystallographic directions of QD alignment in general. © 2009 Elsevier B.V. All rights reserved.},
note = {cited By 17},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Pankaow, N; Panyakeow, S; Ratanathammaphan, S
Formation of In0.5Ga0.5As ring-and-hole structure by droplet molecular beam epitaxy Journal Article
In: Journal of Crystal Growth, vol. 311, no. 7, pp. 1832-1835, 2009, ISSN: 00220248, (cited By 19).
@article{Pankaow2009,
title = {Formation of In0.5Ga0.5As ring-and-hole structure by droplet molecular beam epitaxy},
author = {N Pankaow and S Panyakeow and S Ratanathammaphan},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-63349093931&doi=10.1016%2fj.jcrysgro.2008.11.003&partnerID=40&md5=407e09ae4215ed4eb0b011345bf97e56},
doi = {10.1016/j.jcrysgro.2008.11.003},
issn = {00220248},
year = {2009},
date = {2009-01-01},
journal = {Journal of Crystal Growth},
volume = {311},
number = {7},
pages = {1832-1835},
abstract = {Fabrication of InGaAs ring-and-hole nanostructures was successfully demonstrated by the droplet epitaxy technique using molecular beam epitaxy (MBE). The evolution of surface morphology during growth was monitored in situ by reflection high-energy electron diffraction (RHEED). Droplet-forming conditions were changed by varying substrate temperatures during In0.5Ga0.5 deposition (so-called deposition temperature). Dependence of the ring structural properties on the deposition temperature was investigated. Distributions of InGaAs ring outer diameter, outer height, and inner depth at different deposition temperatures were also examined. It was found that the higher the deposition temperatures, the larger the outer diameter and the higher the outer height of most of the InGaAs rings. However, they had slightly lower densities. Photoluminescence results confirmed the high quality of the nanocrystal. © 2008 Elsevier B.V. All rights reserved.},
note = {cited By 19},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Boonpeng, P; Panyakeow, S; Ratanathammaphan, S
Fabrication of In0.15Ga0.85As nanohloes on GaAs by droplet molecular beam epitaxy Journal Article
In: Journal of Crystal Growth, vol. 311, no. 7, pp. 1843-1846, 2009, ISSN: 00220248, (cited By 1).
@article{Boonpeng2009a,
title = {Fabrication of In0.15Ga0.85As nanohloes on GaAs by droplet molecular beam epitaxy},
author = {P Boonpeng and S Panyakeow and S Ratanathammaphan},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-63349093032&doi=10.1016%2fj.jcrysgro.2008.10.066&partnerID=40&md5=206984df31031eb7c20c92a964642f0c},
doi = {10.1016/j.jcrysgro.2008.10.066},
issn = {00220248},
year = {2009},
date = {2009-01-01},
journal = {Journal of Crystal Growth},
volume = {311},
number = {7},
pages = {1843-1846},
abstract = {This article reports on the fabrication of self-assembled In0.15Ga0.85As nanoholes on GaAs(1 0 0)substrates grown by droplet epitaxy using molecular beam epitaxy. The effects of growth interruption time and substrate temperature were investigated. The surface morphology of In0.15Ga0.85As nanoholes were examined by atomic force microscopy. The results show the dependence of density, depth, and width of nanoholes on the growth interruption time and substrate temperature. This growth technique is simple and flexible. It does not require additional complicated substrate processing and has a potential in developing quantum dots and quantum dot molecules for quantum computation applications. © 2008 Elsevier B.V. All rights reserved.},
note = {cited By 1},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Swe, N C; Tangmattajittakul, O; Suraprapapich, S; Changmoang, P; Thainoi, S; Wissawinthanon, C; Kanjanachuchai, S; Ratanathammaphan, S; Panyakeow, S
In: Journal of Vacuum Science and Technology B: Microelectronics and Nanometer Structures, vol. 26, no. 3, pp. 1100-1104, 2008, ISSN: 10711023, (cited By 3).
@article{Swe2008,
title = {Improved quantum confinement of self-assembled high-density InAs quantum dot molecules in AlGaAsGaAs quantum well structures by molecular beam epitaxy},
author = {N C Swe and O Tangmattajittakul and S Suraprapapich and P Changmoang and S Thainoi and C Wissawinthanon and S Kanjanachuchai and S Ratanathammaphan and S Panyakeow},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-44649158210&doi=10.1116%2f1.2835064&partnerID=40&md5=b01ab372f6260712583b3c271e795c30},
doi = {10.1116/1.2835064},
issn = {10711023},
year = {2008},
date = {2008-01-01},
journal = {Journal of Vacuum Science and Technology B: Microelectronics and Nanometer Structures},
volume = {26},
number = {3},
pages = {1100-1104},
abstract = {Self-assembled, multistack InAs quantum dot molecules (QDMs) were grown by a modified molecular beam epitaxial (MBE) technique, which involves multiple stacking and multiple cycling of the thin-capping-and-regrowth process, so as to obtain a large volume density of quantum dots on the sample. Furthermore, the high-density InAs QDMs were also grown sandwiched either between a double heterostructure (DHS) or between a quantum-well (QW) structure. It was found from microphotoluminescence (μ -PL) measurements that the QDMs sandwiched between these structures give broader PL spectra than those of the as-grown QDMs. The broadening of the PL spectra is associated with the poorer dot size uniformity, which arises from the long and complicated MBE growth processes. However, comparing between the QDMs in the DHS and in the QW structure, the latter give narrower PL spectra. The narrower PL spectra for the QDM-in-QW structure is attributed to the improved quantum confinement effect arising from the use of the QW. © 2008 American Vacuum Society.},
note = {cited By 3},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Boonpeng, P; Panyakeow, S; Ratanathammaphan, S
In-mole-fraction and thickness of ultra-thin InGaAs Insertion layers effects on the structural and optical properties of InAs quantum dots Journal Article
In: Advanced Materials Research, vol. 31, pp. 132-134, 2008, ISSN: 10226680, (cited By 0; Conference of International Conference on Materials for Advanced Technologies, ICMAT 2007 ; Conference Date: 1 July 2007 Through 6 July 2007; Conference Code:72337).
@article{Boonpeng2008,
title = {In-mole-fraction and thickness of ultra-thin InGaAs Insertion layers effects on the structural and optical properties of InAs quantum dots},
author = {P Boonpeng and S Panyakeow and S Ratanathammaphan},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-45749132254&doi=10.4028%2f0-87849-471-5.132&partnerID=40&md5=31d749fcc2214b755f6858330cdccc52},
doi = {10.4028/0-87849-471-5.132},
issn = {10226680},
year = {2008},
date = {2008-01-01},
journal = {Advanced Materials Research},
volume = {31},
pages = {132-134},
publisher = {Trans Tech Publications},
abstract = {InAs quantum dots (QDs) have been grown by solid-source molecular beam epitaxy on different InxGa1-xAs (0 ≤ x ≤ 0.3) to investigate the effect of In-mole-fraction and thickness of InGaAs insertion layer (IL) on the structural and optical properties of the QDs. The density of QDs directly grown on GaAs is 1 × 1010 cm-2, and increase to 1.4-1.8×1010 cm-2 on InGaAs layers which depend on the In-mole-fraction and thickness of InGaAs layers. The effects of In-mole-fraction and thickness of InGaAs insertion layer on optical properties of the QDs are studied by photoluminescence (PL). The FWHM of PL spectrum corresponds to the size distribution of the QDs.},
note = {cited By 0; Conference of International Conference on Materials for Advanced Technologies, ICMAT 2007 ; Conference Date: 1 July 2007 Through 6 July 2007; Conference Code:72337},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Pankaow, N; Panyakeow, S; Ratanathammaphan, S
Nanometer-scale in0.5Ga0.5As ring-like structure grown by droplet epitaxy Journal Article
In: Advanced Materials Research, vol. 31, pp. 123-125, 2008, ISSN: 10226680, (cited By 4; Conference of International Conference on Materials for Advanced Technologies, ICMAT 2007 ; Conference Date: 1 July 2007 Through 6 July 2007; Conference Code:72337).
@article{Pankaow2008,
title = {Nanometer-scale in0.5Ga0.5As ring-like structure grown by droplet epitaxy},
author = {N Pankaow and S Panyakeow and S Ratanathammaphan},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-45749132249&doi=10.4028%2f0-87849-471-5.123&partnerID=40&md5=52017e5fced170380610625114e50d59},
doi = {10.4028/0-87849-471-5.123},
issn = {10226680},
year = {2008},
date = {2008-01-01},
journal = {Advanced Materials Research},
volume = {31},
pages = {123-125},
publisher = {Trans Tech Publications},
abstract = {We have demonstrated the fabrication of InGaAs ring-like nanostructures by droplet-epitaxy technique using molecular-beam epitaxy. Dependence on the substrate temperature and the amount of indium and gallium of the nanostructural properties was investigated. It was found that increasing substrate temperature resulted in larger InGaAs ring size but with lower density and that increasing In0.5Ga0.5 amount resulted in larger InGaAs ring size but with oscillating density. Photoluminescence results confirmed the high quality of the nanocrystal.},
note = {cited By 4; Conference of International Conference on Materials for Advanced Technologies, ICMAT 2007 ; Conference Date: 1 July 2007 Through 6 July 2007; Conference Code:72337},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Jewasuwan, W; Panyakeow, S; Ratanathammaphan, S
The formation of InP ring-shape nanostructures on in0.49Ga 0.51P grown by droplet epitaxy Journal Article
In: Advanced Materials Research, vol. 31, pp. 158-160, 2008, ISSN: 10226680, (cited By 0; Conference of International Conference on Materials for Advanced Technologies, ICMAT 2007 ; Conference Date: 1 July 2007 Through 6 July 2007; Conference Code:72337).
@article{Jewasuwan2008,
title = {The formation of InP ring-shape nanostructures on in0.49Ga 0.51P grown by droplet epitaxy},
author = {W Jewasuwan and S Panyakeow and S Ratanathammaphan},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-45749104144&doi=10.4028%2f0-87849-471-5.158&partnerID=40&md5=e5b262f41dd81374c23b1f3e843e9b18},
doi = {10.4028/0-87849-471-5.158},
issn = {10226680},
year = {2008},
date = {2008-01-01},
journal = {Advanced Materials Research},
volume = {31},
pages = {158-160},
publisher = {Trans Tech Publications},
abstract = {We report on the fabrication of self-assembled InP ring-shape nanostructures on In0.49Ga0.51P by droplet molecular-beam epitaxy. The dependency of InP ring-shape nanostructural properties on substrate temperature and indium deposition rate is investigated by ex situ atomic force microscope (AFM). The nano-craters are formed when indium deposition at 120°C while the ring shape quantum-dot molecules are formed when indium deposition at 150°C or higher. The size, density and pattern of InP ring-shape nanostructures strongly depend on substrate temperature and indium deposition rate during indium deposition.},
note = {cited By 0; Conference of International Conference on Materials for Advanced Technologies, ICMAT 2007 ; Conference Date: 1 July 2007 Through 6 July 2007; Conference Code:72337},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Jevasuwan, W; Panyakeow, S; Ratanathammaphan, S
In-droplet-induced formation of InP nanostructures by solid-source molecular-beam epitaxy Journal Article
In: Microelectronic Engineering, vol. 84, no. 5-8, pp. 1548-1551, 2007, ISSN: 01679317, (cited By 8).
@article{Jevasuwan2007a,
title = {In-droplet-induced formation of InP nanostructures by solid-source molecular-beam epitaxy},
author = {W Jevasuwan and S Panyakeow and S Ratanathammaphan},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-34247626356&doi=10.1016%2fj.mee.2007.01.194&partnerID=40&md5=8ee0c6d8d5d0b484a44deb09461c57bb},
doi = {10.1016/j.mee.2007.01.194},
issn = {01679317},
year = {2007},
date = {2007-01-01},
journal = {Microelectronic Engineering},
volume = {84},
number = {5-8},
pages = {1548-1551},
abstract = {We have successfully obtained self-assembled InP nanostructures on In0.49Ga0.51P layers by solid-source molecular-beam epitaxy using droplet-epitaxy. The growth sequence is initiated by indium deposition which was intended to form indium droplets and followed by irradiating P2 beam to crystallize the indium droplets to InP. Dependence of the surface morphology on the indium thickness and on indium deposition rate was investigated. The nanostructure depends strongly on the indium thickness. It is observed that ring-shape nanostructure is formed when the indium thickness is 1.6 ML and the ring-shape quantum-dot molecule is formed when the indium thickness is thicker than 1.6 ML, with the crystallization under 4 × 10-6 Torr of P2 beam at 200 °C for 5 min. The density, height and ring-shape formation pattern of nanostructures also depend on the indium thickness and on the indium deposition rate. © 2007 Elsevier B.V. All rights reserved.},
note = {cited By 8},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Kiravittaya, S; Songmuang, R; Changmuang, P; Sopitpan, S; Ratanathammaphan, S; Sawadsaringkarn, M; Panyakeow, S
InAs/GaAs self-organized quantum dots on (4 1 1)A GaAs by molecular beam epitaxy Journal Article
In: Journal of Crystal Growth, vol. 227-228, pp. 1010-1015, 2001, ISSN: 00220248, (cited By 13; Conference of 11th International Conference on Molecular Beam Epitaxy ; Conference Date: 11 September 2000 Through 15 September 2000; Conference Code:58293).
@article{Kiravittaya2001,
title = {InAs/GaAs self-organized quantum dots on (4 1 1)A GaAs by molecular beam epitaxy},
author = {S Kiravittaya and R Songmuang and P Changmuang and S Sopitpan and S Ratanathammaphan and M Sawadsaringkarn and S Panyakeow},
editor = {Tu C W Kong M.},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-0035398657&doi=10.1016%2fS0022-0248%2801%2900978-2&partnerID=40&md5=a7aa51d7eedc1ce9b5de916f1d360468},
doi = {10.1016/S0022-0248(01)00978-2},
issn = {00220248},
year = {2001},
date = {2001-01-01},
journal = {Journal of Crystal Growth},
volume = {227-228},
pages = {1010-1015},
address = {Bijing},
abstract = {Self-organized InAs QDs formation on (4 1 1)A GaAs and on controlled (1 0 0) GaAs substrates were studied by in-situ RHEED observation, AFM measurement and PL spectroscopy. The transition from two-dimensional to three-dimensional growth on (4 1 1)A was observed by RHEED pattern transformation to indicate the critical layer thickness of InAs QDs formation. The result is almost the same as that on (1 0 0). Improvement of QDs alignment having dot size uniformity on (4 1 1)A was observed by AFM measurement. Enhanced optical properties of QDs on (4 1 1)A was shown by low-temperature PL spectroscopy. Strong PL peak at 966 nm having FWHM of 35 nm was obtained from the 3-stacked QDs on (4 1 1)A. The narrower PL FWHM of QDs peak on (4 1 1)A comes from the improved uniformity of QDs on (4 1 1)A. © 2001 Elsevier Science B.V.},
note = {cited By 13; Conference of 11th International Conference on Molecular Beam Epitaxy ; Conference Date: 11 September 2000 Through 15 September 2000; Conference Code:58293},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Kiravittaya, S; Manmontri, U; Sopitpan, S; Ratanathammaphan, S; Antarasen, C; Sawadsaringkarn, M; Panyakeow, S
AlGaAs/GaAs/InGaAs composite MQW structures for photovoltaic applications Journal Article
In: Solar Energy Materials and Solar Cells, vol. 68, no. 1, pp. 89-95, 2001, ISSN: 09270248, (cited By 10).
@article{Kiravittaya2001a,
title = {AlGaAs/GaAs/InGaAs composite MQW structures for photovoltaic applications},
author = {S Kiravittaya and U Manmontri and S Sopitpan and S Ratanathammaphan and C Antarasen and M Sawadsaringkarn and S Panyakeow},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-0034826290&doi=10.1016%2fS0927-0248%2800%2900347-0&partnerID=40&md5=0b91108643e1322805ad48e2eb71af19},
doi = {10.1016/S0927-0248(00)00347-0},
issn = {09270248},
year = {2001},
date = {2001-01-01},
journal = {Solar Energy Materials and Solar Cells},
volume = {68},
number = {1},
pages = {89-95},
abstract = {AlGaAs/GaAs/InGaAs composite MQW structures were theoretically studied and simulated. The computer simulation indicated that an appropriate composite MQW, both with symmetrical and non-symmetrical structures, could keep |ψ|2 of quantized carriers at proper locations in electric-field-tilted quantum wells, so the efficient transition by photon absorption would be possible and applicable for photovoltaic cells which have the composite MQW as the active region. The AlGaAs/GaAs MQW and GaAs/InGaAs (4x) SQW structures were separately prepared by MBE and were evaluated for their spectral responses. The AlGaAs/GaAs MQW has a high response at a short wavelengths (peak at 685 nm) due to the quantized states in GaAs wells, while the GaAs/InGaAs SQW has a broader spectral response covering longer wavelengths (600-850 nm) because of the strong absorption in the GaAs barrier and substrate. However, (4x) photoluminescence peaks at 900-1100 nm that were found from GaAs/InGaAs strained quantum wells at room temperature are promising evidence for the longer wavelength spectral response. The AlGaAs/GaAs/InGaAs composite SQW and MQW samples were experimentally prepared by MBE techniques and tested for their optical properties. The broader photoluminescence peak was observed and reflected the nature of the composite structure. The study on the photospectral response of composite MQW structures has been conducted which provides the basic information for high performance solar cell design.},
note = {cited By 10},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Deesirapipat, Y; Thainoi, S; Ratanathammaphan, S; Antarasena, C
In: Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers, vol. 40, no. 4 A, pp. 2127-2131, 2001, ISSN: 00214922, (cited By 0).
@article{Deesirapipat2001,
title = {Simple fabrication technique of symmetrical emitter-collector zinc-doped planar Ga1-xAlxAs/GaAs/Ga1-yAlyAs double heterojunction bipolar transistors},
author = {Y Deesirapipat and S Thainoi and S Ratanathammaphan and C Antarasena},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-0035301741&doi=10.1143%2fjjap.40.2127&partnerID=40&md5=8194f2c1d033749cd1c15a05d16c6cd9},
doi = {10.1143/jjap.40.2127},
issn = {00214922},
year = {2001},
date = {2001-01-01},
journal = {Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers},
volume = {40},
number = {4 A},
pages = {2127-2131},
publisher = {Japan Society of Applied Physics},
abstract = {Symmetrical emitter-collector planar Ga1-xAlxAs/GaAs/Ga1-yAlyAs double heterojunction bipolar transistors have been designed and fabricated. Crystal growth and doping are carried out using liquid phase epitaxy (LPE) technique. Five layers consisting of collector, base, emitter, emitter contact and mask layer, Ga0.6Al0.4As, have been grown consecutively by LPE on GaAs (n+) substrate. After etching the mask layer to open a region for base diffusion, the sample was carried back to the LPE furnace to grow the Zn-doped Ga0.6Al0.4As in order to diffuse Zn to the p-type base. After the process, both the diffusion layer and the mask layer were selectively etched. Ohmic contacts were then made. Finally, the DC characteristics of the transistors were measured to show their symmetrical behaviors.},
note = {cited By 0},
keywords = {},
pubstate = {published},
tppubtype = {article}
}