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Enhancing PV system modeling accuracy with the irradiance intensity selection technique
(2026-06-01)
Songtrai, Sasiwimon
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Chinnavornrungsee, Perawut
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Sriprapha, Kobsak
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Kobayashi, Tomonao
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Niemcharoen, Surasak
This study is a method to improve the accuracy of photovoltaic (PV) power modeling by the irradiance intensity segmentation. The developed model was compared with 2 years of data from PV system in Thailand and the original 1D5P and weight function models to determine accuracy. The results show that by applying the irradiance intensity selection technique with a 1D5P equivalent circuit model improved the accuracy of the proposed model. The proposed method achieved a significantly lower %root mean square error (%RMSE) compared with other models yielding %RMSE values of 0.26% under clear-sky and 2.80% under cloudy conditions. Seasonal evaluation further demonstrated improved prediction accuracy, with the lowest deviation observed during the rainy period, attributed to reduced dust accumulation. A 2 years comparison confirmed the proposed model exhibited the lowest deviation of 0.69%, outperforming conventional PV simulation programs. These findings indicate that irradiance segmentation enhances forecasting performance and provides accurate PV output estimation under real environmental conditions.
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Surface phosphatization of cerium-lanthanum oxides for catalytically inert white pigments
(2025-11-01)
Onoda, Hiroaki
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Wada, Takuma
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Charoonsuk, Thitirat
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Pulphol, Phieraya
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Muanghlua, Rangson
Cerium dioxide (CeO<inf>2</inf>) is a UV-scattering agent commonly employed in sunscreens but suffers from oxidative catalytic activity, raising concerns for dermal applications. To address this issue, surface passivation via phosphatization has been explored, although prior attempts with CeO<inf>2</inf> alone failed to eliminate its intrinsic yellow hue due to low reactivity with phosphoric acid. In this study, we introduce a novel white pigment synthesized via the phosphoric acid-mediated treatment of CeO<inf>2</inf>–La<inf>2</inf>O<inf>3</inf> mixtures. By co-utilizing lanthanum oxide, which readily forms lanthanum phosphate—a white, inert compound—we achieved enhanced suppression of oxidative activity alongside improved whiteness. The composite materials were systematically characterized via X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), particle size analysis, colorimetry (Lab*), and catalytic activity assays. The results reveal that phosphatization preferentially proceeds at lanthanum sites, forming phosphate-rich surface layers that diminish redox activity while maintaining favorable dispersion and smoothness properties. The pigment shows high acid resistance and negligible photocatalytic activity, indicating its potential as a safe, non-reactive alternative for cosmetic formulations. This work advances the development of rare-earth-based functional pigments via a scalable, low-temperature route.
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DIELECTRIC AND FATIGUE LIFE ENHANCEMENT IN BaTiO3/Epoxy RESIN BASED COMPOSITES USED AS PIEZOELECTRIC NANOGENERATOR
(2025-01-01)
Vittayakorn, Wanwilai
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Rerngroen, Nakulkarn
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Sasipongpan, Apinya
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Muanghlua, Rangson
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Vittayakorn, Naratip
This study investigates the enhancement of dielectric properties and fatigue life in BaTiO3/epoxy resin composites utilized as the active material in piezoelectric nanogenerators. Through a systematic approach, various fabrication techniques and composite formulations are explored to optimize the dielectric constants, energy density, and piezoelectricity while mitigating fatigue-related degradation. The physical character, phase formation, and chemical properties of these composites are identified via the optical camera, XRD, and FTIR methods, respectively. The frequency dependence of dielectric properties for all samples is measured by an LCR meter. The hysteresis P-E loops are investigated in order to calculate the energy density and energy loss density of materials. The piezoelectric properties of these composites are performed by studying the generated output voltage and current after applying mechanical force to the samples. Moreover, MWCNT nanomaterials have also been incorporated into these composites in order to improve their dielectric value and fatigue life. The results show that the dielectric constant (εr) and dielectric loss (tanδ) of these composites are independent of frequency. After loading BaTiO3 into the epoxy resin matrix, the εr and tanδ significantly increased with the increasing BaTiO3 amount. The energy density and energy loss density of all composites were calculated from these P-E loops, and it is seen that pure epoxy resin shows the lowest energy density and energy loss density values. After loading BaTiO3 into the epoxy resin matrix, both the energy density and the energy loss density of the composites significantly increased. Moreover, after adding 20 percent by volume of BaTiO3 to the system, the energy density increases by 160% compared with pure epoxy resin. For the effect of MWCNT filler, it is seen that the εr, tanδ, energy density and energy loss density are significantly improved after adding 1.5 vol% of MWCNT into the system. The output current generated by applying mechanical force to the sample increased 27 times after adding MWCNT to the BT-filled epoxy resin composite. Finally, it can be concluded that all experimental results demonstrate significant enhancements in dielectric properties, energy density and electric output current, paving the way for the development of robust and efficient piezoelectric nanogenerators for diverse energy harvesting applications.
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Frictional heat-assisted performance enhancement in dynamic Schottky contact of Al/Ag2Se-based tribovoltaic nanogenerator
(2025-01-01)
Worathat, Supakarn
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Pharino, Utchawadee
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Pakawanit, Phakkhananan
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Rattanachata, Arunothai
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Muanghlua, Rangson
The tribovoltaic nanogenerator (TVNG) has evolved in recent years as a novel type of nanogenerator designed to address the limitations of the standard triboelectric nanogenerator in terms of output signal and charge generation. Besides the outstanding characteristics, the tribovoltaic effect can also well be coupled with another effect to further boost the output performance. In this work, we proposed firstly a frictional heat-assisted performance enhancement in dynamic Schottky contact from the rubbing between n-type silver selenide (Ag<inf>2</inf>Se) and aluminum. The chemical composition and physical characteristics of the Ag<inf>2</inf>Se ceramic were analyzed using X-ray diffraction, scanning electron microscopy, and Synchrotron X-ray tomography techniques. UV–Vis spectroscopy and UPS were also utilized in order to validate the semiconducting property of the n-type Ag<inf>2</inf>Se ceramic. Moreover, the presence of the Schottky junction was demonstrated through the analysis of the current-bias voltage characteristic curve of the Ag<inf>2</inf>Se/aluminum (Al) contact under varying stress and temperature conditions. The built-in electric field plays a crucial part in the tribovoltaic effect by efficiently transferring the excited carriers to an external load through sliding contact between Ag<inf>2</inf>Se and Al. Demonstrating the synergy between tribovoltaic and thermoelectric effects becomes achievable through the excellent thermoelectric property of Ag<inf>2</inf>Se. Herein, the proposed TVNG generated a peak output voltage and current of around 0.7 V and 24.8 nA, respectively, achieving a maximum output power of 12.6 nW at a load resistance of 10 kΩ. The influence of frictional heat on the output performance of the proposed TVNG was well demonstrated by the thermal-induced voltage and enhanced electrical output from continuous sliding. The concepts given in this study establish the basis for the progress of effective energy collection employing semiconducting materials and the advancement of flexible harvesting and sensing device development in the future.
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Acidic dynamics: Unveiling mechanistic insights for improved performance in chitosan triboelectric nanogenerators
(2024-07-01)
Charoonsuk, Thitirat
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Ukasi, Sirinya
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Mokthaisong, Panadta
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Khuntakaew, Pawita
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Hajra, Sugato
In recent years, there has been a surge in interest surrounding the development of chitosan (CS)-based triboelectric nanogenerators (TENG) for powering attachable/portable devices. Despite numerous strategies aimed at enhancing their efficiency, the selection of acid solvent has remained largely unexplored. In this study, various acids, including acetic (CH<inf>3</inf>COOH), succinic (C<inf>4</inf>H<inf>6</inf>O<inf>4</inf>), and citric (C<inf>6</inf>H<inf>8</inf>O<inf>7</inf>) acids, were investigated for their impact on mechanical and electrical output signals. Remarkably, the choice and concentration of acid were found to significantly influence performance. Specifically, employing citric acid rendered the CS solid film more pliable and yielded the highest output signal at optimal concentration levels. Under optimized conditions, the CS-TENG exhibited an open-circuit voltage output (V<inf>OC</inf>) of 157 V and short-circuit current output (I<inf>SC</inf>) of 53 µA—more than triple that of pristine CS-TENG. Mechanistic insights into electrical generation have been elucidated, underscoring the importance of solvent selection in CS TENG fabrication. These findings underscore the potential for tailored acid solvent selection to advance specialized applications in the field.
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Porous Silicon Formation by Stain Etching on Pyramid Surface in U-Shape MSM Photodetector
(2024-01-01)
Muanghlua, Rangson
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Atiwongsangthong, Narin
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Vijafun, Jidapa
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Suttijalern, Kamonwan
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Niemcharoen, Surasak
In this paper, the porous silicon formation on pyramid surface in U-shape MSM photodetector was studied. Stain etching technique was used to prepare porous silicon material. The solution for stain etching contained the mixed solution of hydrofluoric acid (HF), nitric acid (HNO<inf>3</inf>) and deionized water (DI) with ratios 1: 3: 5 and used halogen lamp expouse 30,000 lux between etching for excite porous formation in 2 minutes. Porous silicon was fabricated on pyramid surface in U shape which between metal electrode titanium and aluminum on p-type silicon 20-25 Ω-cm to reduce the reflection of incident light and to increase a photocurrent of MSM photodetector. In the final part of this paper are the comparison physical morhhology and electrical characteristic of porous silicon on pyramid surface in U shape MSM photodetector with pyramid in U-shape MSM photodetector without porous silicon on the surface and planar MSM photodetector. The physical morphology of porous silicon on pyramid surface in U-shape was studied by using scanning electron microscopy (SEM). The electrical characteristic was investigated by using incident light with wave length 635 nm and power 6 mW at bias voltage 10 V. The result of comparison, we found that porous silicon on the surface of pyramid in U-shape MSM photodetector is rougher than pyramid in U-shape MSM photodetector without porous silicon on the surface. The electrical characteristic of porous silicon on pyramid surface in U-shape MSM photodetector respond incident light higher than pyramid in U-shape MSM photodetector without porous silicon on the surface. Therefore the forming porous silicon on the suface of pyramid in U-shape MSM photodetector is appropriate for the fabrication of MSM photodetector with high photocurrent.
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Effect and Determination of Oxide Trapped Charge and Interface Trapped Charge Density of Threshold Voltage Shift in Irradiated MOSFET by Subthreshold Methodology
(2023-10-01)
Ruangphanit, Anucha
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Muanghlua, Rangson
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Wongprasert, Yothin
This paper presents the effects and determination of oxide and interface trapped charge density of threshold voltage shift in irradiated MOSFET by subthreshold methodology. The designed dimension, channel width per channel length (W/L) is 20 µm/20 µm. The threshold voltage is extracted by a linear extrapolation methodology. The over all threshold voltage shifts are caused by oxide trapped charge and interface trapped charge. The subthreshold methodology determines the interface trapped charge. The60Co gamma-ray source was used for irradiation to a total dose of 10 kGy. The results showed that the threshold voltage shift is approximately-24 mV/kGy for NMOS and-27 mV/kGy for PMOS. The subthreshold swing shift is approximately 1.2 mV/dec.kGy for NMOS and 0.9 mV/dec.kGy for PMOS. The oxide trapped charge density N<inf>OT</inf> and interface trapped charge density N<inf>IT</inf> are found to be increased in NMOS and PMOS respectively. The ratio of ΔN<inf>OT</inf>/ΔN<inf>IT</inf> was approximately 2.2 times for NMOS and 2.8 times. Due to the structure, the channel of NMOS is a surface channel whereas the channel of PMOS is a buried channel. Finally, the effect of gamma irradiation on the PMOS was greater than the effect on NMOS observed from the change in threshold voltage and the ratio of ΔN<inf>OT</inf>/ΔN<inf>IT.</inf>.
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Development of Flexible Semiconductors Based on g-C3N4/Cu2O P–N Heterojunction for Triboelectric Nanogenerator Application
(2023-01-01)
Worathat, Supakarn
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Pharino, Utchawadee
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Sriphan, Saichon
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Niemcharoen, Surasak
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Thitirungraung, Wisut
This research aims to develop flexible semiconductors for triboelectric nanogenerator (TENG) applications. The sample powders of graphitic carbon nitride (g-C<inf>3</inf>N<inf>4</inf>) and copper (I) oxide (Cu<inf>2</inf>O) as N-type and P-type semiconductors, respectively, were synthesized. The semiconductors were prepared to be a composite film with alginate. The structure, morphology, and purity of the N- and P-type semiconductors were characterized using X-Ray diffraction and scanning electron microscopy techniques. Through the optical characterization, the N-type semiconductor showed the calculated energy band gap of 2.80 eV, while the P-type semiconductor was 1.90 eV. The P–N junction property of prepared samples was confirmed using a nonlinear current–voltage characteristic. After that, two flexible semiconductors were frictional paired for TENG. Through a vertical contact-separation mode, the P–N junction-based TENG produced a maximum output voltage and current of 3.90 V and 0.44 µA, respectively, with a maximum output power of 0.35 µW at 10 MΩ. In summary, the present work achieved the preparation of flexible P- and N-type semiconductors. The feasibility to harvest the mechanical energy was demonstrated in the TENG configuration. This idea is crucial for the future development of flexible harvesting/sensing devices using a novel concept.
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Gamma-radiation Induced Degradation of the Electrical Characteristics of NMOSFETs
(2022-01-01)
Ruangphait, Anucha
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Kerdpradist, Amonrat
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Muanghlua, Rangson
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Wongprasert, Yothin
In this paper, we present the gamma-radiation induced degradation of the electrical characteristics of N-channel Metal Oxide Semiconductor Field Effect Transistors (NMOSFETs). The exposure was done with a60Co gamma-ray source over the total dose range of 1 kGy to 10 kGy, with a dose rate of 3.9 kGyhr. The effects of irradiation induced degradation on device parameters such as threshold voltage, low field mobility, device transconductance (G<inf>m</inf>), saturation drain current, off state leakage current and subthreshold swing were investigated. The threshold voltage was determined using the linear extrapolation method. The device dimensions with Wide/ Long channel that excluded the Narrow Channel Effect (NCE) and the Short Channel Effect (SCE) were measured. The results showed that the threshold voltage, device transconductance and low field mobility decreased but the saturation drain current, off state leakage current and subthreshold swing increased as the gamma irradiation increased. Finally, the macro parameter models were investigated and discussed.
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Utilization of commodity thermoplastic polyethylene (PE) by enhanced sensing performance with liquid phase electrolyte for a flexible and transparent triboelectric tactile sensor
(2021-04-01)
Charoonsuk, Thitirat
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Muanghlua, Rangson
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Sriphan, Saichon
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Pongampai, Satana
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Vittayakorn, Naratip
To promote the sustainable development of single-used polyethylene (PE) commodity plastic for long-lasting use in advanced electronic devices, this work presented a successful strategy for converting PE plastic bags, which usually end up in landfills, into specifically flexible and transparent triboelectric tactile sensors (TES). In order to enhance the electrical output to meet the practical application, liquid phase electrolytes (LPEs) were introduced between double sides of thin PE layers. LPE utilization had significant influence on the output signal, resulting in an effective response to physical contact with the human hand. The effect of LPE types, i.e., acids, salts and solvent as well as concentration, on output signal was studied and clarified. The scientific working mechanism for PE/LPE TES was described based on the coupling behavior between contact electrification, electrostatic induction and ion conduction within the electric double layer. The PE/LPE TES showed the optimized signal response of V<inf>oc</inf> ~1.6 V, I<inf>sc</inf> ~673 nA and 450 W/cm2, enabled by tunable LPE types and concentrations, thus providing a hundred times more than that of pristine PE. By integrating PE/LPE TES with a signal-processing circuit, wireless application of the complete tactile sensing system has been developed further to make contact with and control home appliances such as a light bulb and an electric fan. Its flexibility and transparency has great potential adaptation for the active tactile system that can be attached to different wearable devices, textiles, or home interior decoration. This work demonstrates a facile strategy for promoting PE plastic as a high value-added electronic product that has the potential to pave the way for development in large-scale industry, and help in treating used plastic in the future. It also has the opportunity to obtain a tactile sensor that is affordable and cost-effective in making a valuable contribution in the global sensor market, thus ensuring sustainable development in both social and economic terms.

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