Somdock, Nuttakrit
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Item type:Publication, Simultaneous Seebeck coefficient and electrical conductivity enhancement of GeSbTe films via Sn addition(2022-06-15); ; Sn-added GeSbTe (GST) thin films were deposited using a co-magnetron sputtering technique. The effects of varying the Sn content through a variable Sn target sputtering power and post annealing at 673 K were investigated. The DC power density applied to the GST target was controlled at 50 W, while the power density of the Sn target was increased from 0 W to 40 W. The results demonstrate the coexistence of the fcc-GST, hcp-GST and SnTe phases in the Sn-added GST thin films. The substitution of Sn at the Ge-site increases the crystallization speed and leads to defects and lattice disordered local arrangement in the GST films, causing the Seebeck coefficient to increase. The SnTe phase was created as a result of the high Sn content in the sample due to the over-doping limit of Sn into the GST structure. The presence of SnTe in Sn-doped GST films increased the electrical conductivity. The maximum power factor of 17.0 μW/cmK<sup>2</sup> at 450 K was obtained at an Sn content of 14.7 at%. These results indicated that the thermoelectric properties of Sn-doped GST films were improved via the formation of an appropriate amount of SnTe composite. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Triboelectric Nanogenerator Prepared from Poly(vinylidene Fluoride-Hexafluoropropylene) Polymer Composite(2023-01-01); ; In this work, poly(vinylidene fluoride-hexafluoropropylene)/reduced graphene oxide films were prepared by the solution casting method with N,N-dimethylformamide (DMF) and DMF/acetone mixed solvents. The effects of reduced graphene oxide and solvent type on the morphology and crystal structure of the composite films were investigated by using scanning electron microscopy, Fourier-transform infrared spectroscopy, and Raman spectroscopy, respectively. The morphology study showed that the addition of acetone in the film process resulted in the occurrence of tiny pores on the film surfaces. The reduced graphene oxide incorporated into the PVDF-HFP was able to promote the formation of β- phase in the composites. The maximum power of 15.58 µW was obtained from the films using DMF/acetone mixture as solvent. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Post-ball-milling-assisted solid-state synthesis of Bi4O4SeCl2: A low thermal conductivity material(2025-02-01); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Enhanced thermoelectric properties of Cu2Se via Sb doping: An experimental and computational study(2023-02-01); ; - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Enhancement of thermoelectric properties in rapidly synthesised β-Cu2Se using optimized Cu content and microwave hybrid heating(2024-01-15); ; - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Enhanced thermoelectric properties of bismuth telluride via Ultra-Low thermal conductivity BOSC compound addition(2024-12-01); ; This study aimed to enhance the thermoelectric properties of bismuth telluride by adding Bi<inf>4</inf>O<inf>4</inf>SeCl<inf>2</inf> (BOSC). Commercial N-type bismuth telluride was mixed with BOSC powder in varying concentrations. As the BOSC content increased, the carrier concentration also rose due to chlorine atoms acting as donor impurities. Despite this increase, the power factor values of the samples with BOSC additives did not significantly differ from those of the bare bismuth telluride sample. However, the total thermal conductivity decreased significantly with the addition of BOSC, reaching a minimum value of 0.54 W·m<sup>–1</sup>·K<sup>–1</sup> at 150 °C for the sample with 1 wt% BOSC. Notably, the ZT value for the sample with 1 wt% BOSC was about 0.86, which is four times higher than that of the bare bismuth telluride sample. Our findings demonstrate superior thermoelectric performance, indicating a more efficient modification of thermoelectric properties through the addition of BOSC to the bismuth telluride matrix. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Enhanced antimony telluride thermoelectric generators: From material synthesis to device applications(2025-12-01); ; This study investigates the effect of Bi₄O₄SeCl₂ (BOSC) addition (0–4 wt%) on the thermoelectric performance of p-type Bi₀.₅Sb₁.₅Te₃ synthesized via high-energy ball milling. XRD analysis revealed lattice incorporation at 1 wt% BOSC, while higher concentrations led to phase separation. The 1 wt% BOSC sample exhibited a significantly reduced total thermal conductivity of 0.28 W/m·K, compared to 0.46 W/m·K in the undoped sample, attributed to enhanced phonon scattering. Despite moderate decreases in electrical conductivity and Seebeck coefficient, a peak ZT of 1.02 at 50 °C was achieved—representing a ∼54 % improvement over the undoped material. Furthermore, a prototype thermoelectric module fabricated with BOSC-doped legs produced a power density of 17.6 mW/cm² under a 150 °C temperature gradient. These results demonstrate that BOSC is an effective additive for reducing thermal conductivity and enhancing overall thermoelectric performance, offering potential for energy harvesting applications at moderate temperatures. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Graphene addition improved figure of merit in SnTe prepared by the rapid hybrid microwave solid-state method(2022-02-01); ; ; We successfully synthesised SnTe-based powders (SnTe, Sn<inf>0.95</inf>Bi<inf>0.05</inf>Te, and SnTe with graphene addition) by a hybrid microwave solid-state method. This demonstrated comparable thermoelectric performance to the conventional heating method but had low energy consumption and rapid synthesis. Graphene addition to SnTe materials resulted in significant reduction of thermal conductivity. The SnTe with 5 wt% graphene exhibited a reduction in overall thermal conductivity from ∼10 W m<sup>−1</sup> K<sup>−1</sup> for SnTe to ∼2 W m<sup>−1</sup> K<sup>−1</sup> at 325 K and showed a moderate power factor. The Debye model was used to explain the origin of the effects of graphene on lattice thermal conductivity. The dimensionless figure of merit was increased by five times, from 0.07 for SnTe to 0.35 for SnTe with 5 wt% graphene. Our results demonstrated an effective method and additive material to synthesise and enhance the thermoelectric properties of SnTe materials. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Post-annealing effects on (00l) texture, Cl/Se ratio, and electrical and glass-like thermal transport in Bi₄O₄SeCl₂(2026-04-25); ; Naemchanthara, KittisakchaiBi₄O₄SeCl₂ is a heteroanionic layered material with intrinsically low lattice thermal conductivity and anisotropic charge transport. In this work, the effects of post-annealing temperature on the crystallographic texture, anion chemistry, defect evolution, and transport properties of Bi₄O₄SeCl₂ were systematically investigated. Polycrystalline Bi₄O₄SeCl₂, synthesized by solid-state reaction combined with high-energy ball milling, was post-annealed at 400–700 °C. X-ray diffraction and electron microscopy revealed that post-annealing eliminated the residual BiOCl precursor phase, enhanced the (00 l) preferred orientation, and promoted grain growth up to 600 °C, followed by partial texture degradation at 700 °C due to recrystallization. Energy-dispersive spectroscopy showed progressive Se and Cl volatilization during annealing, leading to an increased Cl/Se ratio. The carrier mobility and electrical conductivity reached maximum values at 600 °C, consistent with improved texture and layered-domain connectivity. Thermal transport remained lattice-dominated and only weakly temperature-dependent. The phonon mean free path, estimated using kinetic theory, was in the sub-nanometer range (∼0.25–0.57 nm), comparable to the interatomic spacing, indicating glass-like phonon transport. Representative HRTEM observations also revealed dislocation-related lattice defects and locally distorted regions, suggesting that vacancy disorder and local strain fields may provide additional phonon scattering. These results demonstrate that post-annealing optimizes electrical transport through phase purification, texture development, and defect-mediated carrier regulation, while the lattice thermal conductivity remains fundamentally limited by intrinsic glass-like phonon transport in Bi₄O₄SeCl₂. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Synthesis of Fe–Cu Alloys via Ball Milling for Electrode Fabrication Used in Electrochemical Nitrate Removal from Wastewater(2025-07-01); ; ; Srirach, PisanFe and Cu powders were mixed at a 50:50 ratio. Then, Fe-Cu alloys were prepared using the ball milling technique with different milling times of 6, 12, 18, 24, 30, 36, and 42 h. The crystalline structure was analyzed using X-ray diffraction (XRD), and it was found that the optimum milling time was 30 h. The homogeneity of the Fe and Cu elements in the Fe–Cu alloys was analyzed using the scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM–EDX) mapping technique. Additionally, the crystal orientation of the Fe–Cu alloys was investigated using transmission electron microscopy (TEM). To fabricate the cathode for nitrate removal via electrolysis, an Fe–Cu alloy milled for 30 h was deposited onto a copper substrate using mechanical milling, then annealed at 800 °C. A pulsed DC electrolysis method was developed to test the nitrate removal efficiency of the Fe–Cu-coated cathode. The anode used was an Al sheet. The synthesized wastewater was prepared from KNO<inf>3</inf>. Nitrate removal experiments from the synthesized wastewater were performed for durations of 0–4 h. The results show that the nitrate removal efficiency at 4 h was 96.90% compared to 74.40% with the Cu cathode.