Onlaor, Korakot
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Preferred name
Onlaor, Korakot
Alternative Name
Onlaor, K.
Main Affiliation
Email
korakot.on@kmitl.ac.th
49 results
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Item type:Publication, Preparation of pH Sensor Based on Extended-Gate Field-Effect Transistor with Spinel ZnCo2O4 Thin Films by Electrostatic Spray Deposition(2023-12-01); ; Electrostatic spray deposition was applied to prepare pH sensing with spinel ZnCO<inf>2</inf>O<inf>4</inf> thin films based on the measurement of extended-gate field-effect transistors (EGFET). The influence of annealing temperatures on the characteristics of the prepared films was analyzed. The structural and morphological properties of the annealed ZnCo<inf>2</inf>O<inf>4</inf> films were assessed by x-ray diffraction, x-ray photoelectron spectroscopy, Raman spectroscopy, scanning electron microscopy, and contact angle measurement. The effect of the ZnCo<inf>2</inf>O<inf>4</inf> annealing temperature on the characteristics of pH sensing for the prepared ZnCo<inf>2</inf>O<inf>4</inf> films in EGFET measurement were examined with pH buffer solutions in a pH range of 2–12 at room temperature. The sensing films annealed at 550°C demonstrated a high voltage and current sensitivity at 67.6 mV/pH and 1.033 (µA)<sup>½</sup>/pH, with linearity values of 0.9968 and 0.9991, respectively. Moreover, the annealed 550°C ZnCo<inf>2</inf>O<inf>4</inf> film exhibited low hysteresis at 4.99 mV and high retention stability. The results revealed that the pH sensing of the ZnCo<inf>2</inf>O<inf>4</inf> EGFET device showed a super-Nernstian sensitivity, which indicated the influence of the surface properties of the annealed film. Therefore, the ZnCo<inf>2</inf>O<inf>4</inf> film should be considered a potential option for the pH sensing layer in EGFET applications. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Effect of anodizing voltage on anodic titanium dioxide (ATO) growth based on an ethylene glycol solution containing NH4F(2016-01-01) - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Humidity sensor based on graphene oxide film prepared by simple drop-casting process(2017-01-01); In this work, the film of graphene oxide was deposited by drop-casting process for humidity sensor device. The structural property of graphene oxide film was performed by Raman spectroscopy. The humidity device was fabricated onto the indium tin oxide, as the transparent electrode. The device exhibited the adsorption and desorption behaviors of humidity in a range of 23-93 %RH. The complex impedance measurement was used to explain the mechanisms of the humidity device. The equivalent circuit model of the device was demonstrated. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Electrical Bistable Properties of P-25 TiO2 Nanoparticles Composited with PVP for Memory Devices(2019-10-01); In this work, P-25 titanium dioxide nanoparticles (TiO<inf>2</inf> NPs) were composited with poly-vinylpyrrolidone (PVP) at various concentrations of TiO<inf>2</inf> NPs. The bistable memory devices were fabricated by spin coating from a prepared PVP:TiO<inf>2</inf> NPs solution on indium tin oxide (ITO) electrodes with the device structure of ITO/PVP:TiO<inf>2</inf> NPs/Al. The maximum ON/OFF current ratio of the bistable memory devices was approximately 10<sup>5</sup> at a reading voltage of +1 V. The mechanism of the memory device can be expressed by theoretical fitting between the experimental results and conduction models. Moreover, a retention time test for continuous read operations of the device is presented. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Electrical bistability of tris-(8-hydroxyquinoline) aluminum (Alq 3)/ZnSe organic-inorganic bistable device(2012-01-01); ; ; We present that the electrical bistability in organic-inorganic bistable devices based on tris-(8-hydroxyquinoline) aluminum (Alq<inf>3</inf>) and zinc selenide (ZnSe) with the tri-layer structure of Alq<inf>3</inf>/aluminum (Al)/ZnSe. The current-voltage characteristics of the bistable device exhibit two electrical states as low (OFF state) and high (ON state) conductivity with ON/OFF ratio about four orders of magnitude. The conduction mechanisms in both ON and OFF states were analyzed by theoretical model. In the OFF state, the conduction mechanisms can be explained by thermionic emission model, which the ON state can be described by ohmic conduction model. The retention times of both states are more than 8000 s, and the device can reproduce continuous write-read-erase-read switching cycles. Moreover, for the organic-inorganic bistable device was kept at one year in ambient condition without encapsulation. The device still exhibited the electrical bistable behavior. Consequently, the ZnSe layer may be led to improve the lifetime property of the bistable device which acted as a self-encapsulating layer. © 2011 Elsevier B.V. All rights reserved. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Effect of ascorbic acid on structural properties of ZnO nanoparticles prepared by precipitation process(2015-07-01); In this work, zinc oxide nanoparticles (ZnO NPs) was prepared by chemical precipitation process. To study the influence of the ascorbic acid on properties of ZnO nanoparticles, the ascorbic acid was added to precursor solution at different molar ratio of ascorbic acid (AA) and zinc during the synthesis process. The characterizations of ZnO nanoparticles were performed using X-ray diffraction (XRD), Raman spectroscope, and field emission scanning electron microscopy (FE-SEM). The effect of ascorbic acid on the structural properties of ZnO NPs was investigated. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Preparation of iron oxide (Fe2O3) nanoparticles thin film for humidity sensing device(2021-09-15); ; - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Impedance spectroscopy studies of DCM doped Alq3 organic material(2013-10-29); ; In this work, we report on the frequency-impedance characteristics of dye-doped organic material. The device structure is glass substrate/indium tin oxide/DCM:Alq<inf>3</inf>/Aluminum 100 nm. The influence of doping concentraion has been investigated by impedance spectroscopy. The impedance characteristics of the dye-doped organic material can be modelled by simply adopting the conventional equivalent circuit with the simple combination of resistors and capacitor network. The variation of bulk resistance with applied bias voltage as a result of the Space Charge Limited Conduction (SCLC) mechanism for charge conduction. © (2013) Trans Tech Publications, Switzerland. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Preparation of Nanofibers of Poly (methyl methacrylate) Composited with Few-Layer-Graphene for Anticorrosion Layer(2022-12-01); ; An anticorrosion layer is a significant component that prevents the corrosion process in materials. In this work, a nanofiber of poly (methyl methacrylate) composited with few-layer-graphene was prepared as an anticorrosion layer. An electrospinning process was applied to prepare composite nanofiber on a metal substrate at various concentrations of few-layer graphene. The physical properties of the composite nanofiber were investigated with field-emission scanning electron microscope, Raman spectroscopy, and contact angle measurement. The corrosion behavior was tested in an aqueous solution of 3.5% by weight of sodium chloride. It was found that a few-layer graphene concentration of 2 wt% in polymethacrylate showed the optimum anticorrosion on aluminum sheet, as observed on a Tafel graph. Compared with the uncoated metal, the coated aluminum sheet was protected against corrosion with a protection efficiency of 99.33%. The prepared materials prevented the infiltration of water and solution ions into the metal plate. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Flexible and fully transparent WORM memory devices based on Ag nanoparticles blended with poly(ethylene-co-vinyl acetate)(2019-12-01); ; Silver nanoparticles (Ag NPs) blended with poly(ethylene-co-vinyl acetate) (EVA) were used as an active layer to fabricate flexible and fully transparent memory devices by using the spin-coating method followed by the thermal roll lamination technique with the structure of ITO/EVA:Ag NPs/ITO. The devices exhibited a non-volatile write-once-read-many-times (WORM) memory type and possessed current bi-stability with ON/OFF current ratio within the range of 10<sup>4</sup>-10<sup>5</sup> at a reading voltage of +1 V. The data continuous read operations reached more than 10 h, which revealed the stability of the memory devices over a long period of time. The conduction mechanisms of the memory device could be explained by theoretical models and proposed by electron trapping at the trapping center of Ag NPs inside the EVA matrix. In addition, the memory device showed a fast response of 231 ns and was fully transparent with maximum transmittance of the device at 83.2%. Further, the devices could be operated under the bending condition of more than 0.83% strain.