Browsing by Author "Huang, Kuan-Chieh"

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A counter electrode based on hollow spherical particles of polyaniline for a dye-sensitized solar cell
(2012)
Huang, Kuan-Chieh
;
Hu, Chih-Wei
;
Tseng, Chen-Ya
;
Liu, Chen-Yu
;
Yeh, Min-Hsin
Hollow spherical polyaniline (hsPANI) particles are synthesized and deposited on an ITO/glass substrate to prepare a counter electrode (designated as hsPANI-CE) for a dye-sensitized solar cell (DSSC). The structure and crystallization of the hsPANI particles are characterized by using high resolution transmission electron microscopy (HR-TEM), field-emission scanning electron microscopy (FE-SEM), X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), and Raman spectra. A power-conversion efficiency (h) of 6.84% is obtained for the DSSC with the hsPANI-CE, while it is 6.02% in the case of the DSSC with a CE based on pristine PANI (designated as PANI-CE). Such enhancement is attributed to the hsPANI film having a larger active surface area (A) of 0.191 cm(2), compared to that of the PANI film (A = 0.126 cm(2)), both values being estimated by a rotating disk electrode (RDE). Cyclic voltammetric (CV) curves have evidenced that the electro-catalytic ability of the hsPANI-CE for the reduction of tri-iodide (I-3(-)) ions is higher than that of the PANI-CE. As a reference, the DSSC with a Pt-sputtered CE gives an h of 7.17%. Electrochemical impedance spectroscopic (EIS) spectra are used to substantiate the photovoltaic behaviors. The results suggest that the film consisting of hsPANI particles can be a potential catalytic layer for the replacement of Pt in the CE of a DSSC.
Computations of the Signal-to-Noise Ratio for Medical X-Ray Imagers
(2014-08-01)
Lo, Yu-Chen
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Huang, Kuan-Chieh
;
Yang, Kei-Hsiung
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光電系統研究所
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影像與生醫光電研究所
If the signal in a medical X-ray imaging detector is formed by integrating the scintillation (or electrical) pulses, rather than by counting them, the signal-to-noise ratio is reduced by a factor which depends on the pulse height distribution. Formulas are expanded from Swank\'s publication to derive the signal-to-noise ratio for any given optical or electrical pulse-size distribution. A new quantity called noise-equivalent absorption is defined which bears a simple relationship to the signal-to-noise ratio of integrated X-ray imaging as the quantum absorption to the signal-to-noise ratio of photon-counting X-ray imaging.
High performance dye-sensitized solar cells based on platinum nanoparticle/multi-wall carbon nanotube counter electrodes: The role of annealing
(2012-04-01)
Huang, Kuan-Chieh
;
Wang, Ying-Chiao
;
Chen, Po-Yen
;
Lai, Yi-Hsuan
;
Huang, Jen-Hsien
A composite film is coated on the FTO using a solution, containing a synthesized dispersant, poly(oxyethylene)-segmented imide (POEM), dihydrogen hexachloroplatinate (H2PtCl6), and multi-wall carbon nanotube(MWCNT); the thus coated FTO is used as the counter electrode (CE) for a dye-sensitized solar cell (DSSC). The annealing temperature of the composite film, in the range of 110-580 degrees C, is found to be crucial for optimizing its catalytic ability to obtain the best possible performance for the DSSC. About 47% loss in mass for the POEM/H2PtCl6/MWCNT composite is observed from 110 to 390 degrees C, due to not only the progressive formation of PtNPs from H2PtCl6 but the decomposition of POEM. Therefore, the efficiencies (eta) of DSSCs applying these CEs are enhanced from 1.28 +/- 0.08% (110 degrees C) to 8.47 +/- 0.21% (390 degrees C). The mass of the composite loses dramatically under heating above 390 degrees C, due to the decomposition of MWCNTs. The eta decreases to 7.77 +/- 0.15% at 450 degrees C because the decrease in surface roughness of film. PtNPs grow in sizes from 450 to 580 degrees C, resulting in the further decrease in catalytic ability of film and the observed eta from 7.77 +/- 0.15% to 7.19 +/- 0.21%. (C) 2011 Elsevier B.V. All rights reserved.
Nanographite/polyaniline composite films as the counter electrodes for dyesensitized solar cells
(2011)
Huang, Kuan-Chieh
;
Huang, Jen-Hsien
;
Wu, Chia-Hui
;
Liu, Chen-Yu
;
Chen, Hsin-Wei
Nanographite/polyaniline (NG/PANI) composite films were developed and characterized, and the performances of the dye-sensitized solar cells (DSSCs) employing these composite films as the counter electrode (CE) were evaluated in this study. The nanographite/aniline (NG/ANI) particle was firstly synthesized by a reflux method and served as the monomer for the electro-polymerization of the NG/PANI composite films. The surface modification of NG by ANI was confirmed by EDX mapping, TEM image, zeta-potential, and UV-Vis absorption measurements. The electro-polymerized NG/PANI composite films were characterized by Raman spectroscopy, XPS, and conducting-AFM, which verified the successful incorporation of NGs in the PANI films. The electro-catalytic activity of the NG/PANI composite film was evaluated using the positive-feedback mode of scanning electrochemical microscopy (SECM), by which a comparable heterogeneous rate constant (k(s)(0)) for the ferrocene/ ferrocenium (Fc/Fc(+)) redox pair was obtained and compared with that of a sputtered Pt. The DSSC employing the NG/PANI (20 mC cm(-2)) CE exhibited a higher short-circuit current density (J(SC)) but lower fill factor (FF), and gave a comparable power-conversion efficiency (eta) of 7.07%, as compared to that of a DSSC containing a sputtered Pt CE (eta = 7.19%).
Using a low temperature crystallization process to prepare anatase TiO(2) buffer layers for air-stable inverted polymer solar cells
(2010-01-01)
Huang, Jen-Hsien
;
Wei, Hung-Yu
;
Huang, Kuan-Chieh
;
Chen, Cheng-Lun
;
Wang, Rui-Ren
In this study, we fabricated inverted polymer solar cells featuring titanium dioxide (TiO(2)) as the electron collection layer and vanadium (V) oxide (V(2)O(5)) as the hole collection layer. TiO(2) films (anatase phase) were prepared by combining electrochemical deposition with high-pressure crystallization. The low temperature process used to obtain the TiO(2) films minimized interdiffusion of Ti and In species between the TiO(2) and ITO films and maintained the conductivity of the indium tin oxide substrate. The inverted device reached a power conversion efficiency of 3.22% and exhibited much better stability under ambient conditions relative to that of the corresponding conventional device.
Using a low temperature crystallization process to prepare anatase TiO2 buffer layers for air-stable inverted polymer solar cells
(2010-01-01)
Huang, Jen-Hsien
;
Wei, Hung-Yu
;
Huang, Kuan-Chieh
;
Chen, Cheng-Lun
;
Wang, Rui-Ren
In this study, we fabricated inverted polymer solar cells featuring titanium dioxide (TiO2) as the electron collection layer and vanadium (V) oxide (V2O5) as the hole collection layer. TiO2 films (anatase phase) were prepared by combining electrochemical deposition with high-pressure crystallization. The low temperature process used to obtain the TiO2 films minimized interdiffusion of Ti and In species between the TiO2 and ITO films and maintained the conductivity of the indium tin oxide substrate. The inverted device reached a power conversion efficiency of 3.22% and exhibited much better stability under ambient conditions relative to that of the corresponding conventional device.