Phetchakul, Toempong
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Preferred name
Phetchakul, Toempong
Alternative Name
Phetchakul, T.
Main Affiliation
Email
toempong.ph@kmitl.ac.th
12 results
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Item type:Publication, Study on temperature effect on p-n and Zener junction for PTAT temperature sensor(2008-10-06) ;Songmalai, P.; ; ; Supadech, J.Research on a new compact BJT PTAT temperature sensor structure has been reported. The zener junction-connected BJT transistor and Base-Emitter voltage of transistor can be temperature dependent. The performance of new compact PTAT circuit can be improved by using difference in thermal characteristics between p-n and zener junction. ΔV/ΔT can be further increased by connecting p-n and zener junction in series. The results show that ΔK/ΔT of the circuit increased by 6.77 timed or 85% compared with conventional PTAT and connecting two p-n and zener junction in series. The result show that ΔK/ΔT of the circuit increased by 3.3 timed or 70%compared with proposed circuit the output voltage is large enough so that it can be used directly without additional amplifier. This also improves S/N ratio and the unique linearity of PTAT is still preserved. The working temperature of circuit is between -60°C to 160°C © 2008 IEEE. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Magnetotransistor sensing by the difference of base and collector current(2004-12-01); ;Leepattarapongpan, ChanaA bipolar magnetotransistor with asymmetric topology, by using only three terminals, is sensitive to specific magnetic field direction. The sensing mechanism is the difference between collector current I<inf>c</inf> and base current I<inf>B</inf>. The experiment is the comparison between the sensitivity during three terminal mode and regular mode. At each condition, the three terminal mode sensitivity is less than that obtained from regular mode. It indicates that three terminals can be designed for optimum devices. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Photoconductor diamond film detector(2008-10-06) ;Jesen, S. ;Thaiyotin, L. ;Cheirsirikul, S.Diamond film was synthesized on a silicon substrate by MPCVD (Microwave Plasma Chemical Vapor Deposition) process and used to fabricate a photoconductor for the detection of UV light. The photoconductor was fabricated on free standing diamond film and operation in a planar. This paper presents the spectral response of photoconductor, concentration of boron doping, times and temperature. The device shows good response to UV light and a very low response to visible light. Furthermore, the device reveals little change in spectral response with increasing temperature at all wavelengths. © 2008 IEEE. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Effect of base width and implantation dose on performance of 3-terminal magnetotransistor(2007-12-01) ;Woradet, Jaroenmit; ;Chareankid, Sompong; Klunngien, NipapanThis paper presents the effect of base width and implantation dose on electrical carriers in the magnetotransistor deflected by the Lorentz force (F<inf>L</inf>) from magnetic field. The structure of magnetotransistor is designed like a structure of a PNP bipolar junction transistor which comprises of 3 terminals, i.e., emitter, collector and base. The base width (L) is varied (10, 20 and 30 μm) where the spacing between collector and base is fixed at 40 μm. The emitter and collector regions are doped with boron (BF <inf>2</inf>) at the dose of 3×10<sup>15</sup>, 5×10<sup>15</sup> and 1×10<sup>16</sup> ions/cm<sup>2</sup>. It is found that the sensitivity is increased when increasing L and the implantation dose. It is also demonstrated that the linear relationship between the output voltage of the magnetotransistor circuit and magnetic field can be obtained. © 2007 IEEE. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Extraction of defect in doping silicon wafer by analyzing the lifetime profile method(2008-01-01); ; Poyai, A.The total leakage current in silicon p-n junction diodes compatible with 0.8 μm CMOS technology is investigated. The generation lifetime is a key parameter for the leakage current, which can be obtained from the current-voltage (I-V) and the capacitance-voltage (C-V) characteristics. As will be shown, the electrically active defect from ion implantation process generated in p-n junction can be extracted from the generation current density. © 2008 Trans Tech Publications, Switzerland. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Implantation-induced defects analysis base on activation energy diagnostics(2009-12-01); ; Poyai, AmpornLow power consumption device can be realized by low junction leakage current. This leakage current relates to the defects in the depletion region of p-n junction. Among variety process steps, implantation step may generate defects. Therefore, the implantation-induced defects have been studied from the activation energy which has been obtained from the leakage current of p-n junction. The different geometry p-n junctions have been fabricated by a standard CMOS technology. The current-voltage (I-V) and high frequency capacitance-voltage (C-V) characteristics of p-n junctions with temperature dependence have been measured. The electrically active defects from implantation process can be extracted from the junction generation current density versus temperature. Base on this analysis, it will be demonstrated that the implantation-induced defects have been found in p+-n-well more than in n+-psubstrate. Finally, the possible nature of the defect will be discussed. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Alcohol sensor based on multi-wall carbon nanotube(2009-12-01); ;Sangnual, AssucholWe have demonstrated multi-walled carbon nanotube (MWCNTs) based sensors, which are capable of detecting alcohol vapor. The properties of the sensor were as a function of baking times at ethanol flow rate 200 cc/min and nitrogen gas flow rate 200 cc/min. Moreover, the various of baking times were observed that the highest sensitivity was obtained at baking time of 25 minutes at 70 ° C can be explained for residual of ethanol on the surface .It was found that the optimum operating at room temperature (25 °C). It is expected that many applications of CNTs-based sensors will be explored in future as the interest of the nanotechnology research in this field increases. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Selective growth of CNT on Ni/Cu substrate(2007-08-28); ;Chomnawang, Nimit ;Cheirsirikul, Somsak ;Nakachai, RatthapongThis paper presents a method for selective growth of CNT films. Specific areas for CNT growing were defined by patterning Ni electrodes on a Cu substrate using lithography process. CNT films were grown on the substrate by HFCVD method at atmospheric pressure using ethanol and hydrogen as sources. The films were examined and confirmed with SEM, Raman and EDX analysis. We observed that CNT only grow in selective areas of Ni. None can be grown on Cu background. This finding suggests a novel method of selective growth of CNT using Cu as a masking layer. Preliminary results also show possibility of growing CNT across the gaps between 3D interdigital Ni electrodes fabricated by LIGA technique. © 2007 IEEE. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, UV photodetector from Schottky diode diamond film(2002-03-01) ;Thaiyotin, L. ;Ratanaudompisut, E.; ;Cheirsirikul, S.Supadech, S.Diamond film was synthesized on a silicon substrate by hot-filament CVD and used to fabricate a Schottky photodiode for the detection of UV light. This paper presents an improved structure of photodiode, which reduces the effect of grain boundaries in the polycrystalline diamond film. The Schottky photodiode was fabricated on free-standing diamond film and operation in a vertical direction can be expected to reduce the effect of grain boundaries. The device shows good response to UV light and a very low response to visible light. The dark current is less than 10 pA. The device response time is less than 20 μs. Furthermore, the device reveals little change in spectral response with increasing temperature at all wavelengths. © 2002 Elsevier Science B.V. All rights reserved. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, UV photodetectors from B-doped diamond film(2000-12-01) ;Thaiyotin, L.; ;Cheirsirikul, S.Supadech, S.The diamond film synthesized on silicon substrate by hot-filament CVD has been used to fabricate photoconductive and photodiode structures for the detection of UV light. The photoconductive device which the higher boron doped has a greater different response between UV light and visible light more than the lower one, but it has more dark current and response time. The Al schottky photodiode fabricated on the B-doped diamond film showed lower dark current and shorter response time than photoconductive device.
