Browsing by Author "Chen, Chien Chon"

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Anodic TiO2 Nanotube Arrays for Dye-Sensitized Solar Cells Characterized by Electrochemical Impedance Spectroscopy
(2012-12-01)
Wu, Hui Ping
;
Li, Lu Lin
;
Chen, Chien Chon
;
Diau, Eric Wei Guang
;
土木工程學系
This paper reports on the microstructure of anodic titanium oxide (TiO2) and its use in a dye-sensitized solar cell (DSSC) device. When voltages of 60 V were applied to titanium foil for 2 hr under 0.25 wt% NH4F + 2 vol% H2O+C2H4(OH)(2), TiO2 with a nanotube structure was formed. The film, which had a large surface area, was used as an electron transport film in the DSSC. The DSSC device had a short-circuit current density (J(sc)) of 12.52 mA cm(-2), a fill factor (FF) of 0.65, an open-voltage (V-oc) of 0.77 V, and a photocurrent efficiency of 6.3% under 100% AM 1.5 light. The internal impedance values under 100%, 64%, 11%, and 0% (dark) AM 1.5 light intensities were measured and simulated using the electrical impedance spectroscopy (EIS) technique. The impedance characteristics of the DSSC device were simulated using inductors, resistors, and capacitors. The Ti/TiO2, TiO2/Electrolyte, electrolyte, and electrolyte/ (Pt/ITO) interfaces were simulated using an RC parallel circuit, and the bulk materials, such as the Ti, ITO and conducting wire, were simulated using a series of resistors and inductors. The impedance of the bulk materials was simulated using L-0+R-0+R-b, the impedance of the working electrode was simulated using (C-1//R-1)//(R-a+(C-2//R-2), the electrolyte was simulated using C-3//R-3, and the counter electrode was simulated using C-4//R-4. (C) 2012 Elsevier Ltd and Techna Group Sri. All rights reserved.
Enhanced Efficiency of Dye-Sensitized Solar Cells Using Anodic Titanium Oxide Nanotube Arrays
(2009)
Chen, Chien Chon
;
Jehng, Wern Dare
;
Li, Lu Lin
;
Diau, Eric Wei-Guang
;
應用化學系
This paper concerns the microstructure of the anodic titanium oxide (ATO, TiO(2)) nanotube (NT) and its use for the dye-sensitized solar cell (DSSC) device. The ATO length was controlled by various electrolytes and anodic time at various constant applied voltages. The lengths of the NTs at 0.3-0.5 and 0.9-22 mu m were controlled by 0.5 vol % HF and 0.58 wt % KF aqueous solutions for varied periods of anodization (1-24 h). The 0.5 wt % NH(4)F electrolyte in ethylene glycol can produce 4-41 mu m for varied periods of anodization (0.5-8 h). ATO made of 0.3 (0.5 vol % HF), 12 (0.5 wt % KF), and 18 mu m (0.5 wt % NH(4)F) was used for the DSSC anode; the best cell performance attained 0.13, 3.76, and 6.18%. The DSSC made of 18 mu m ATO has a short-circuit current density (J(sc)) of 13.45 mA/cm(2), a fill factor of 0.64, an open voltage (V(oc)) of 0.72 V, and a photocurrent efficiency of 6.18% under an air mass 1.5 illumination test.
Enhanced electromagnetic properties of Fe-Cr-Si alloy powders by sodium silicate treatment
(2015-07-15)
Chen, Shih Fan
;
Chang, Hsuan Yao
;
Wang, Shea Jue
;
Chen, Shih Hsun
;
Chen, Chien Chon
The Fe-Si-Cr alloy powders were successfully modified by using the phosphatizing and sodium silicate coating processes. The optimized surface pre-treatment for Fe-Si-Cr powder was phosphatized in 2 wt.% phosphoric solution and further treated with 4 wt.% sodium silicate solution at 75 degrees C for 30 min. These treatments increased the high-frequency stability for Fe-Si-Cr alloy powders, and the annealed cores further showed the enhanced performance of permeability, impedance, quality factor and anti-corrosion ability. Comparing with the Fe-Si-Al alloy, the Fe-Si-Cr also showed a superior performance in density, moldability and saturated magnetic induction. (C) 2015 Elsevier B.V. All rights reserved.
Evaluation of CO2 Absorbent/ De-absorbent by AAO/ CaO Membrane
(2013-01-01)
Chen, Chien Chon
;
Wang, Yen Po
;
土木工程學系
;
Department of Civil Engineering
This paper discussed the fabrication of anodic aluminum oxide (AAO)/CaO core-shell membrane by anodization and sol-gel processes and evaluated the relationship between the Al2O3/CaO and CO2 by thermodynamic calculation. According to thermodynamic property that CaO can reacts with CO2 forming calcium carbonate (CaCO3) in a lower temperature ranges, CaCO3 can also be decomposed to CaO in a higher temperature ranges. Because the reversible reaction property that CaO can be a CO2 absorbent/ de-absorbent. We address that AAO based on core-shell nanotubes structure to achieve such a demand. The captured CO2 can further convert to fuel material of hydrocarbons.
Influence of annealing treatment on soft magnetic properties of Fe76Si10B10Cr2Y2 amorphous ribbon
(2015-04-05)
Chen, Shih Fan
;
Hung, Chi Yu
;
Wang, Shea Jue
;
Chen, Shih Hsun
;
Chen, Chien Chon
In this study, the influence of annealing treatment on soft magnetic properties of Fe76Si10B10Cr2Y2 amorphous ribbon was investigated. Alloy ribbons were synthesized by the single roller melt-spinning method. The magnetic measurements of the as-cast ribbon were inspected, including M-s, H-c and T-c. The value of Ms was 1.25 T, H-c was 22.84 A/m and T-c was 564.4 K. The soft magnetic properties of the optimum parameter for the annealing temperature and annealing time was at 500 degrees C for 3 min, M-s was 1.37 T and H-c was 1.11 A/m. Therefore, the soft magnetic properties of the Fe76Si10B10Cr2Y2 alloy ribbon was significantly improved through the annealing treatment. (C) 2015 Published by Elsevier B.V.
Novel morphology and solidification behavior of eutectic bismuth-tin (Bi-Sn) nanowires
(2009-07-29)
Chen, Shih Hsun
;
Chen, Chien Chon
;
Chao, Chuen Guang
;
材料科學與工程學系
;
Department of Materials Science and Engineering
In the present work we show a simple and robust fabrication process for dense and continuous bismuth-tin (Bi-Sn) eutectic nanowires. The Bi-Sn eutectic nanowires of 200 nm diameter and several tens of mu m, in length were fabricated by a vacuum hydraulic force method. The alloy melt was injected into an anodic aluminum oxide (AAO) template to form nanowires after melt solidification. For this process, nanowires were formed from non-atomic deposition with liquid alloy; in this way, the composition of nanowires can be controlled precisely in stoichiometry. The Bi-Sn melt was restricted inside the AAO which has a low thermo-conduction and long period cooling rate around the melt. On the other hand, the heat flow is along the tube Z-axis and the melt is solidified from the AAO bottom to top because of the open pore on the AAO top. The eutectic nanowires were found to be dense and continuous with a uniform diameter throughout the length of the wires and with a lamellar microstructure along the wires' Z-axis. In addition, the alternative segmental compositions showed that the ratio of tin to bismuth is approximately 33:1. (C) 2009 Elsevier B.V. All rights reserved.
The Fabrication of Sub-micron Size Cesium Iodide X-Ray Scintillator
(2015-01-01)
Hun, Chien Wan
;
Chen, Po Chun
;
Huang, Ker Jer
;
Chen, Chien Chon
;
醫療電子系統實驗室
The cesium iodide (CsI) scintillator can converts incident X-ray into visible light with very high conversion efficiency of optical photons. The incident energy, response time, film thickness, sample size, and spatial resolution require in engineering and medical applications are difference. A smooth and flat surface and single crystal structure of CsI enhance the X-ray to visible light conversion. However, the regular CsI is soft and extremely hygroscopic; it is very difficult to polish to obtain a smooth and optical flat plane. In order to obtain a good quality of CsI scintillator for X-ray application we used an ordering channel as template and formed sub-micron CsI wire in the template. The fabrication process including: (1) Ordering structure of nano or sub-micron channels were made by an anodization method; (2) fill CsI scintillated film on the channel by CsI solution, (3) fill CsI melt into the channel formation single crystal of sub-micron crystalline scintillator after solidification. The non-vacuum processes of anodization and solidication methods were used for the sub-micron CsI scintillator column formation that is cost down the scintillator fabrication. In addition, through the fabrication method, the ordering structure scintillator of scintillator can be made by anodic treatment and die casting technology with low cost and rapid production; moreover, the film oxidized metal tubes of the tubular template can be further manufactured to nano tubes by adjusting electrolyte composition, electrolysis voltage, and processing time of anodic treatment, and the aperture size, the thickness and the vessel density of the nano tube can be controlled and ranged from 10 nm to 500 nm, 0.1 mu m to 1000 mu m, and hundred million to thousand billion tube/cm(2), respectively.