Khemasiri, Narathon

Preferred name

Khemasiri, Narathon

Alternative Name

Khemasiri, N.

narathon.kh@kmitl.ac.th

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Vertical alignment TiO2 nanotube based on Ti film prepared via anodization technique
(2016-01-01)
Aimpanakit, Kamon
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Jessadaluk, Sukittaya
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Tongmaha, Sunisa
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Supati, Attawit
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Khemasiri, Narathon
A highly ordered nanotube TiO<inf>2</inf> was successfully prepared from sputtered Ti metal film using anodization process. Ethylene glycol and ammonium fluoride was introduced as the electrolyte solution. The applied of anodizing voltage was systematically controlled between 20-60 volts along fabrication process, respectively. The physical characteristic of the fabricated TiO<inf>2</inf> nanotube including anodizing rate, tube diameter and tube width was investigated through the characterization system as field emission scanning electron microscope (FE-SEM). According to cross-section FE-SEM photograph, the anodizing rate and tube width significantly increases when the anodizing voltage was future increased due to higher the electric field. Moreover, the tube diameter directly depends with the anodizing voltage also. The anodizing voltage provides a significant role on the feature of TiO<inf>2</inf> nanotube. Finally, the fabricated nanotube TiO<inf>2</inf> is potentially promising for Photo-activated application and Nanostructure template.
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High sensitive nanocrystal titanium nitride EG-FET pH sensor
(2013-10-29)
Rayanasukha, Yossawat
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Porntheeraphat, Supanit
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Bunjongpru, Win
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Khemasiri, Narathon
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Pankiew, Apirak
Solid state pH-sensor device with high efficiency has successfully prepared by using TiN thin film as sensing membrane of extended gate field effect transistor (EG-FET) device. This research has described the physical properties and sensing characteristics of TiN membrane thin film which deposited on SiO<inf>2</inf>/Si substrate through reactive D.C. magnetron sputtering system. Thenanocrytal-TiNwith anatasestructure depended on substrate heating conditions was revealed from glancing angle x-ray diffraction. The I<inf>DS</inf>-V<inf>GS</inf> measurement in the standard buffer solutions showed that the sensitivity of fabricated TiN-EGFET pH deviceis 59.82mV/pH. © (2013) Trans Tech Publications, Switzerland.
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Determination of thickness and optical properties of tantalum oxide thin films by spectroscopic ellipsometry
(2014-01-01)
Chananonnawathorn, Chanunthorn
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Khemasiri, Narathon
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Srichaiyaperk, Thanat
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Samransuksamer, Benjarong
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Horprathum, Mati
Tantalum oxide (Ta<inf>2</inf>O<inf>5</inf>) thin films were prepared, at different deposition time, by a DC reactive magnetron sputtering. During the deposition, a high-quality tantalum target was sputtered under argon and oxygen ambience on to silicon (100) and glass substrates. The prepared thin films were systematically characterized for both physical and optical properties based on spectroscopic ellipsometry (SE), and consequently confirmed by several methods. With the SE physical models, we could determine the thin film thickness as well as their inhomogeneity. The films thickness results were directly confirmed by field-emission scanning electron microscopy (FE-SEM) used to observe cross-sections, and surface profiler used to measure the physical thickness of the films. With the SE optical models, we applied both the Cauchy and Tauc-Lorentz dispersions in order to obtain the optical constants, to be directly compared with those from the Swanepoel method (SM). Our result showed that from the SE analyses, the SE physical model was obtained as the multi-layer configurations. The obtained Ta<inf>2</inf>O<inf>5</inf> thin film thickness was closely related with the measured result from the FE-SEM cross-sectional micrographs and the surface profiler. For the optical characteristic, the double layer physical model was best optimized with the Tauc Lorentz dispersion model for the most accurate results. In comparison, the SM technique also demonstrated a capability to determine both the film thickness and its refractive index only from some samples. Therefore, this study proved that the SE technique successfully and accurately determine both the physical and optical properties of the Ta<inf>2</inf>O<inf>5</inf> thin films. © (2014) Trans Tech Publications, Switzerland.
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Fabrication of zinc oxide nanorods for photoelectrochemical water splitting application
(2016-01-01)
Phetban, Poosuda
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Khemasiri, Narathon
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Kalasung, Sukol
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Jessadaluk, Sukukittaya
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Horprathum, Mati
Zinc oxide nanorods (ZnO-NRs) as a photoelectrochemical water splitting electrode have been fabricated by the seed-assisted hydrothermal process. Initially, ZnO-seed thin film was deposited on indium doped tin oxide (ITO) via DC magnetron sputtering system. Period to fabricate ZnO-NRs, the precursor concentration of zinc nitrate (Zn(NO<inf>3</inf>)<inf>2</inf>) and hexamethylenetetramine (HMTA) were precisely controlled during 10-50 mM, meanwhile the ratio was constantly kept at 1:1. The crystallography and surface morphology of the fabricated ZnO-NRs were investigated by X-ray diffraction (XRD) and field emission scanning electron microscope (FE-SEM). The XRD patterns perform wurtzite ZnO crystal structure of with the prefered orientation in (002) and (101) plane. According to FE-SEM photograph, growth rate, density and diameter of the fabricated ZnO-NRs electrode significantly increase, with the increasing of the precursor concentration. This precursor concentration provides a crucial role on the feature of ZnO-NRs for photoelectrochemical water splitting electrode. Finally, the photoelectrochemical water splitting performance was examined and provided that the precursor concentration became close to 30 mM in 1 M Na<inf>2</inf>SO<inf>4</inf> exhibited the highest photocurrent.
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High performance metal surface coating using Ta2O5 thin film prepared by D. C. magnetron sputtering
(2014-01-01)
Khemasiri, Narathon
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Chananonnawathorn, Chanunthorn
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Horprathum, Mati
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Eiamchai, Pitak
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Chindaudom, Pongpan
Tantalum oxide (Ta<inf>2</inf>O<inf>5</inf>) thin films were deposited as the protective layers for the metal surface finishing by the DC reactive magnetron sputtering system. The effect of the Ta<inf>2</inf>O<inf>5</inf> film thickness, ranging from 25 nm to 200 nm, on the physical properties and the anti-corrosive performance were investigated. The grazing-incidence X-ray diffraction (GIXRD) and the atomic force microscopy (AFM) were used to examine the crystal structures and the surface topologies of the prepared films, respectively. The XRD results showed that the Ta<inf>2</inf>O<inf>5</inf> thin films were all amorphous. The AFM micrographs demonstrated the film morphology with quite smooth surface features. The surface roughness tended to be rough when the film thickness was increased. To examine the protective performance of the films, the poteniostat and galvanometer was utilized to examine the electrochemical activities with the 1M NaCl as the corrosive electrolyte. The results from the I-V polarization curves (Tafel slope) indicated that, with the Ta<inf>2</inf>O<inf>5</inf> thin film, the current density was significantly reduced by 3 orders of magnitude when compared with the blank sample. Such results were observed because of fully encapsulated surface of the samples were covered with the sputtered Ta<inf>2</inf>O<inf>5</inf> thin films. The study also showed that the Ta<inf>2</inf>O<inf>5</inf> thin film deposited at 50 nm yielded the most extreme protective performance. The Ta<inf>2</inf>O<inf>5</inf> thin films therefore could be optimized for the smallest film thickness for highly potential role in the protective performance of the metal surface finishing products. © (2014) Trans Tech Publications, Switzerland.
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Study of optical and electrical properties of tin doped cobalt-phthalocyanine thin films prepared by thermal co-evaporation
(2018-09-05)
Tammarugwattana, Narin
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Jessadaluk, Sukittaya
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Khemasiri, Narathon
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Rahong, Sakon
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Rangkasikorn, Adirek
The aim of this research is to study the specific properties e.g. surface morphology, optical absorption as well as electrical conductivity of tin-doped cobalt-phthalocyanine (CoPc) thin film prepared by thermal co-evaporation. The concentration of tin metal dopant is controlled via evaporation rate during film's preparation. The change of tin quantity leads to the significant changes not only in morphology but also in molecular packing of the doped films. Moreover, the dramatic increase in both carrier mobility and carrier concentration should provide the enhancement in electrical conductivity of the doped films. By controlling the specific properties of the tin-doped CoPc thin film, the increasing efficiency of optoelectronic applications based on metal-phthalocyanine could be achieved.
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Tantalum oxide bio-photonics thin film grown by gas-timing innovation technique
(2013-09-18)
Khemasiri, N.
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Porntheeraphat, S.
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Horprathum, M.
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Chananonnawathorn, C.
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Bunjongpru, W.
Tantalum oxide (TaxOy) as high refractive index material has been grown on p-type silicon and quartz substrates by R.F. magnetron sputtering with our innovative technique called "reactive-gas timing". The reactive gas timing technique is an on-off time period sequence between argon (Ar) and oxygen (O2) plasma during sputtering process. The technique of gas-timing plays the effect on the properties of TaxOy thin film. The bombarded Ar-plasma was varied at 2, 5 and 8 sec, while the period of reactive O2-plasma was kept at 5 sec in this experiment. The physical and optical properties were investigated by using X-ray diffraction (XRD), Atomic Force Microscope (AMF), UV-Visible spectrometer and Spectroscopic Ellipsometer, respectively. The XRD spectra and AFM photographs show all films are amorphous phase with smooth feature. Meanwhile the transmittance of sputtered thin film decreases with 10% and the absorption edge shifts to lower energy with the increasing of the argon period from 2 sec to 8 sec. The refractive index as showed by ellipsometry slightly increases from 2.08 to 2.17 at wavelength 550 nm with the increasing of argon period from 2 sec to 8 sec. The increasing of the refractive index might dues to tantalum (Ta) rich which consists in thin films. The Ar-plasma period in the deposited film plays an important role on the properties of the TaxOy thin films especially as optical refractive index material. © 2013 SPIE.
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Phase formation polycrystalline vanadium oxide via thermal annealing process under controlled nitrogen pressure
(2017-10-20)
Jessadaluk, S.
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Khemasiri, N.
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Rahong, S.
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Rangkasikorn, A.
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Kayunkid, N.
This article provides an approach to improve and control crystal phases of the sputtering vanadium oxide (V<inf>x</inf>O<inf>y</inf>) thin films by post-thermal annealing process. Usually, as-deposited V<inf>x</inf>O<inf>y</inf> thin films at room temperature are amorphous phase: post-thermal annealing processes (400 °C, 2 hrs) under the various nitrogen (N<inf>2</inf>) pressures are applied to improve and control the crystal phase of V<inf>x</inf>O<inf>y</inf> thin films. The crystallinity of V<inf>x</inf>O<inf>y</inf> thin films changes from amorphous to α-V<inf>2</inf>O<inf>5</inf> phase or V<inf>9</inf>O<inf>17</inf> polycrystalline, which depend on the pressure of N<inf>2</inf> carrier during annealing process. Moreover, the electrical resistivity of the V<inf>x</inf>O<inf>y</inf> thin films decrease from 10<sup>5</sup> Ω cm (amorphous) to 6×10<sup>-1</sup> Ω cm (V<inf>9</inf>O<inf>17</inf>). Base on the results, our study show a simply method to improve and control phase formation of V<inf>x</inf>O<inf>y</inf> thin films<inf>.</inf>
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Effect of operated pressure on anticorrosive behavior of Ta2O5 thin film grown by D.C. reactive magnetron sputtering system
(2013-10-29)
Khemasiri, Narathon
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Chananonnawathorn, Chanunthorn
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Horprathum, Mati
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Rayanasukha, Yossawat
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Phromyothin, Darinee
Tantalum oxide (Ta<inf>2</inf>O<inf>5</inf>) thin films, 100 nm thick were deposited by D.C. reactive magnetron sputtering system at different operated pressure on unheated p-type silicon (100) wafer and 304 stainless substrates. Their crystalline structure, film surface morphology and optical properties, as well as anticorrosive behavior, were investigated. The structure and morphology of films were characterized by grazing-incidence X-ray diffraction (GIXRD) and atomic force microscopy (AFM). The optical properties were determined by spectroscopic ellipsometry (SE). The corrosion performances of the films were investigated through potentiostat and immersion tests in 1 M NaCl solutions. The results showed that as-deposited Ta<inf>2</inf>O<inf>5</inf> thin films were amorphous. The refractive index varied from 2.06 to 2.17 (at 550 nm) with increasing operated pressure. The corrosion rate of Ta<inf>2</inf>O<inf>5</inf> thin film improves as the operated pressure decreases. The Ta<inf>2</inf>O<inf>5</inf> thin films deposited at 3 mTorr operated pressure could be exhibited high performance anticorrosive behavior. © (2013) Trans Tech Publications, Switzerland.
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Growth of ZnO nanorods via low temperature hydrothermal method and their application for Hydrogen production
(2017-01-01)
Phromyothin, Darinee
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Phatban, Poosuda
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Jessadaluk, Sukittaya
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Khemasiri, Narathon
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Kowong, Rattanachai
Here, we illustrate the growth of ZnO-NRs through low temperature hydrothermal process on ZnO thin film seed layer. Indium Tin Oxide (ITO) is selected to be substrate material for all experimental condition. The crucial parameters in the growth process are systematically studied. The precursor concentration of zinc nitrate (Zn(NO<inf>3</inf>)<inf>2</inf>) and hexamethylenetetramine (HMTA) were varied from 10 mM to 100 mM, respectively. Regarding to FE-SEM images found that the morphology of ZnO-NRs strongly corresponds with the precursor concentration. The average diameter of the ZnO-NRs starts increasing from 104.38 nm to 325 nm when the precursor concentration was risen during 10 - 60 mM. However, the nanorod-like dense film structure due to the coalescence occurred when the precursor concentration reached to 80 mM. The synthesized ZnO-NRs demonstrate a potential promising as photoanode electrode in electrochemical system for hydrogen production.

Khemasiri, Narathon

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