Khlayboonme, S.Tipawan

Preferred name

Alternative Name

Khlayboonme, S. Tipawan

Khlayboonme, S. T.

Main Affiliation

School of Science

s.tipawan.kh@kmitl.ac.th

Now showing 1 - 10 of 16

Some of the metrics are blocked by your
consent settings
Insights into the properties and possible bonding states of radiofrequency-magnetron-sputtered indium tin oxide thin films acquired using ultraviolet–visible spectroscopy data for cost-effective material characterization
(2023-12-01)
Khlayboonme, S. Tipawan
Indium tin oxide (Sn-doped In<inf>2</inf>O<inf>3</inf>) is an optical material that is widely utilized in designing modern optoelectronic devices. To demonstrate the efficiency of ultraviolet–visible spectroscopy as a primary analysis tool for thin-film characterization, Sn-doped In<inf>2</inf>O<inf>3</inf> films were deposited under untreated and annealed conditions. The optical parameters of these films were determined based on the transmission–reflection spectra recorded by an ultraviolet–visible spectroscopy laboratory setup. Through four-point probing, energy dispersive spectroscopy, and contact angle measurements, the electronic-band structures and chemical bonding states of the thin films were estimated. The transmission spectra confirmed that the post-annealing treatment promoted film homogeneity. Deeper insights into the optical parameters revealed that annealing encouraged Sn atom incorporation into the film structure and better stable phase formation. The incorporation of Sn atoms resulted in the substitution of Sn4+ into the In3+ sites of the In<inf>2</inf>O<inf>3</inf> lattice and formation of the SnO phase. Notably, our evaluation of the film properties based on data acquired from ultraviolet–visible spectroscopy revealed good consistency with the data acquired from Hall-effect, X-ray diffractometry, and X-ray photoelectron spectroscopy investigations.
Some of the metrics are blocked by your
consent settings
Phase-shifting interferometry for surface roughness measurement on glass substrates
(2014-01-01)
Suriyasirikun, S.
;
Khlayboonme, S. T.
;
Thowladda, W.
Phase-shifting interferometry based on Michelson interferometer is purposed to measure surface roughness of glass slides which are widely used as substrates for thin-film coating processes. For the interferometry system, an optical flat with a flatness of λ/20 is used as a reference mirror. The high accuracy of the phase-shifting is achieved by a piezoelectric-driven linear translation stage of the reference mirror. The reference-phase difference between the twointerfering beams is shifted by every π/2 in phase-shifting. Five frames of interferograms under various phase differences of 0, π/2, π, 3π/2 and 2p are recorded by a CCD camera. Each image pixel of these frames is interpreted to access interference intensity information by five-step phaseshifting algorithm for phase calculation, which in turn relates to surface height. The purpose-built interferometry is tested by the surfaces of two optical flats with flatness of λ/10 and λ/4, which are used as the test surfaces. Our measured flatness results are consistent with those of the commercial optical profilometer. The usefulness of the purpose-built interferometry is demonstrated on two types of the glass slides. Aluminum thin films are also deposited on these glass slides by the RF magnetron sputtering method to enhance reflectivity of the glass slide surfaces. The surface profiles and flatness parameters of these glass slides have been reported. © (2014) Trans Tech Publications, Switzerland.
Some of the metrics are blocked by your
consent settings
Effect of SnCl4 concentration on transparent and conducting undoped tin oxide thin films
(2016-01-01)
Khlayboonme, S. Tipawan
;
Thanomngam, Pitiporn
;
Thowladda, Warawoot
The purpose-built pyrolysis system based on an ultrasonically generated aerosol has been successfully used for deposition of highly transparent and conductive undoped tin (IV) oxide thin films. The morphological, structural, optical and electrical properties as well as electronic structures of the films for different concentrations of SnCl<inf>4.</inf>5H<inf>2</inf>O used as the starting precursor were investigated. FE-SEM displayed the substrate surfaces were uniformly covered with the film. The film thickness varied with the precursor concentration. XRD patterns showed the deposited films were a tetragonal phase and presented random orientations. The optical transmission spectra of all films revealed highly transmittance in the visible region. Refractive index of the films was between 1.85 and 2.0. XPS spectra for the Sn 3d<inf>5/2</inf> and Sn 3d<inf>3/2</inf> confirmed that the films were composed of SnO and SnO2 phases. The non-stoichiometric composition decreased with increasing concentration of the precursor. The films deposited with 0.30 M showed the highest conductivity and carrier concentration of 17 ω-1cm-1 and 9.5 x 1019 cm-3, respectively. The disagreement of relation between XPS and Hall measurement suggested the higher carrier concentration arose from incorporation of residual chlorine from the solution precursor during deposition into the films. The interstitially incorporated chlorine considerably influenced the electrical properties of the films.
Some of the metrics are blocked by your
consent settings
Impact of Al-doping on structural, electrical, and optical properties of sol-gel dip coated ZnO:Al thin films
(2021-07-01)
Khlayboonme, S. Tipawan
;
Thowladda, Warawoot
Aluminum-doped ZnO (AZO) thin films were coated on glass substrates using the sol-gel dip-coating technique. We investigated the effect of Al-doping level on the surface morphology, crystal structure, atomic bonding, and optical and electrical properties of the AZO films. The Al-doping levels in the sol-gel solution were 0, 0.25, 0.50, 1.0, 1.5, and 3.0% with a Zn precursor concentration of 0.50 M. The results show that the grain boundary increased with the doping level, while the crystallite size decreased from 27.2 to 14.2 nm. The AZO films were subjected to tensile stress. The Al-doping levels ≤ of 1.5% encouraged the intensity of the (002) x-ray diffraction peak. The center of the (002) peak shifted from 34.46° to 34.51°, and that of the E2highRaman mode shifted from 435.0 to 432.4 cm-1. Doping with 1.5% Al resulted in a maximum electron concentration of 4.7 × 1018 cm-3 with a minimum resistivity of 2.6 × 10-1 Ω cm and a mobility of 5.14 cm2/V.s. The Urbach energy increased from 88 to 120 meV with increasing doping level. For the AZO films doped with Al (≤1.5%), the analysis of the UV-vis spectra reveals that the position of the conduction band (CB) minimum of the films shifted from -0.16 to -0.21 eV and shifted outward from the valence band (VB). Further Al doping to 3.0% resulted in a VB shift toward CB. The optical band gap reached a maximum of 3.33 eV at 1.5% Al. The combination of tensile stress and electron density due to Al doping influences the shift in the optical band gap of the AZO films. The crystal structure, atomic bonding, and electronic band structure of ZnO films can be modified by Al doping.
Some of the metrics are blocked by your
consent settings
Transition between monoclinic and tetragonal β phases induced by reactive oxygen gas in RF-sputtered V2O5 thin films
(2022-11-01)
Khlayboonme, S. Tipawan
Thin films of V<inf>2</inf>O<inf>5</inf> are promising materials for applications in chromogenic devices, such as gas sensors and contactless optical thermal sensors. Therefore, controlling the formation of the various phases of V<inf>2</inf>O<inf>5</inf> is important. The device performance, in relation to satisfactory coloration efficiency and fast response, strongly depends on the characteristics of the phase incorporated in the film structure. To better understand the phase formation in these films, thin films of V<inf>2</inf>O<inf>5</inf> were deposited by RF magnetron sputtering using an O<inf>2</inf>-reaction technique from a metallic V target, and the influence of RF power and O<inf>2</inf> levels on the transition between the β-monoclinic and β-tetragonal phase structures was investigated by X-ray diffractometer. The films were also evaluated using Auger-electron, Raman-, and UV-vis spectrometers to determine their composition, chemical, and electronic properties to assess the effects of the two sputtering parameters. The mechanism underlying the development of film properties is related to the plasma characteristics and species observed by optical emission spectroscopy. Increasing the RF power resulted in a higher phase content of the β-monoclinic and α-orthorhombic phase, whereas an increasing the oxygen levels induced a phase transition towards the β-tetragonal phase of V<inf>2</inf>O<inf>5</inf>. Films with different phase contents exhibited different optical energy bandgaps. Plasma diagnostics showed that increasing the RF power increased the thickness of plasma sheaths on the target surface. The thinner sheath on the target surface further increased the β-tetragonal phase content. The variation between β-monoclinic and β-tetragonal phase content was expected because of the bombardment of energetic O− ions that were accelerated from the plasma sheath toward the growth surface. A deeper understanding of the transition between β phases in V<inf>2</inf>O<inf>5</inf> films can enable better phase control, which can improve film application towards various sensing devices, particularly chromic- or temperature-sensors.
Some of the metrics are blocked by your
consent settings
Underlying mechanism of Al incorporation in sol-gel-based dip-coated ZnO:Al thin films
(2024-07-15)
Khlayboonme, S. Tipawan
Al-doped ZnO films were applied to glass substrates using a sol-gel-based dip-coating method. The chemical composition, surface morphology, crystal structure, and optical and electrical properties were examined to elucidate the mechanism underlying doping efficiency. The optimum Al-doping was 1.00 at%. Al doping induced an increase in the crystallite size, light transmission, optical band gap energy, and carrier concentration but decreased the resistivity of the films. Excessive doping level beyond 1.00 at% degraded all the characteristics of the films. The underlying mechanism of the Al dopant atoms in the ZnO lattice is related to the growth units. The addition of aluminum nitrate promoted the formation of Zn(OH)<inf>2</inf> growth units in the solution, whereas its further addition resulted in the formation of additional Zn(OH)<inf>2</inf>, along with the Zn(OH)<inf>4</inf>2−. The deterioration in the characteristics of the films was attributed to the Zn(OH)<inf>4</inf>2− formation. Understanding the relation between the film characteristics and growth-unit formation is a base tool to increase the optimum Al-doping level, improving film application towards high performance of optoelectronic devices.
Some of the metrics are blocked by your
consent settings
Optical Properties of CuCdS Thin Film Prepared by Vacuum Thermal Evaporation Technique
(2023-01-01)
Hankoy, Montree
;
Treetornkeerati, Paramapat
;
Fungfuang, Natasia
;
Khlayboonme, S. Tipawan
;
Kitiwan, Mettaya
This study reports on the synthesis and characterizations of copper cadmium sulfide (CuCdS) thin films prepared using the vacuum thermal evaporation technique with copper sulfide and CdS as precursors in a 1:1 molar ratio. The structural properties of the thin films were analyzed using X-ray diffraction (XRD) which revealed that the main composition of the thin film was CdS with the preferred orientation of the (101) plane. The optical properties were examined using UV–Vis spectrophotometry. The photosensitivity of the films was determined using I–V measurements performed with a two-probe technique. The prepared CuCdS thin films have high optical transmittance of 92%.
2
Some of the metrics are blocked by your
consent settings
RF-sputtered V2O5 thin films on two different glass substrates
(2021-01-01)
Khlayboonme, S. Tipawan
;
Thowladda, Warawoot
Thin V<inf>2</inf>O<inf>5</inf> films were deposited on two different commercial soda-lime glass substrates (A and B) by O<inf>2</inf> reactive radio frequency magnetron sputtering using a vanadium target. The influences of the surface energy and roughness of the substrates on the structure and atomic bonding of the films were examined. The film on substrate A was polycrystalline, with eight crystal orientations, whereas the film on substrate B yielded an intense (001) diffraction peak of α-V<inf>2</inf>O<inf>5</inf> and a weak (200) peak of β-V<inf>2</inf>O<inf>5</inf>, indicating preferred orientation along these planes. Structural analyses indicated that substrate B with lower surface energy and higher roughness enhanced the formation of a layered a-V<inf>2</inf>O<inf>5</inf> structure.
1
Some of the metrics are blocked by your
consent settings
Plasma impedance tuning effect on nanostructure of diamond films
(2013-10-25)
Thowladda, Warawoot
;
Khlayboonme, S. T.
The morphology and structure of nanocrystalline diamond films as well as the plasma chemistry were studied by altering the plasma impedance. These impedances related to electron density were altered via the matching system. Two films were grown by the microwave plasma under different values of the plasma impedance, resulting in low and high electron densities in the plasma. By the use of measurements of plasma impedance and optical emission, the lowering of an inductive component of the impedance, indicating an increasing electron density, encouraged H-radical concentration present in the plasma. As the plasma was changed to the high electron density, Raman spectra of the films showed the sp3 Raman peak shifted from 1325 to 1328.5 cm-1 with narrower broadening. This behavior arose from an increase in grain size, corresponding to images from a field emission scanning electron microscope. Raman spectra of G-peak position and white light reflectometry showed a reduction in sp2 carbon content of the film. The G-peak shifted from 1564 to 1541 cm-1 and refractive index increased from 1.84 to 2.16. The formation of the films related to the concentrations of H and CH3 radicals. The plasma impedance affected the radical concentrations. © (2013) Trans Tech Publications, Switzerland.
1
Some of the metrics are blocked by your
consent settings
Nanocrystalline diamond films deposited by two-step approach from CH4/H2 microwave plasma: The influence of reactor pressure
(2013-08-30)
Khlayboonme, S. T.
;
Thowladda, W.
The morphology, growth rate and atomic-bonding structure of nanocrystalline diamond films deposited on Si substrates were investigated under various pressures of the reactor. The films were deposited by CH<inf>4</inf>/H<inf>2</inf> microwave plasma with two-step deposition and H<inf>2</inf>-plasma cleaning processes. The pressures of 1, 2, 5, 9, and 25 kPa were used for deposition. In situ gas-phase species, including electron density, were monitored by an optical spectrometer and impedance analyzer. The films were characterized by SEM, Raman microscope, and white light reflectrometer. When the pressure increased, the surface smoothness and diamond grain size increased, amorphous carbon content decreased, and the intensity ratio of CH/H<inf>β</inf> for the growth step increased. The growth rate was in proportional to the ratio of CH/H<inf>β</inf> for the nucleation step but in inverse proportion to the electron density. The growth rates decreased from 370 nm/h for 1 kPa to 320 nm/h for 2 kPa. After that, the growth rate rapidly increased to 460 nm/h for 9 kPa, but it gradually decreased to 450 nm/h for 25 kPa. The film refractive indices were 2.16 for 5 kPa, 2.21 for 9 kPa, and 2.38 for 25 kPa. The films grown under 1 and 2 kPa showed highly light absorption. © (2013) Trans Tech Publications, Switzerland.
1

Khlayboonme, S.Tipawan

Filters

Settings

Sort By

Results per page