Browsing by Author "Lin, Lu-Yin"

Now showing 1 - 5 of 5

Conducting polymer-based counter electrode for a quantum-dot-sensitized solar cell (QDSSC) with a polysulfide electrolyte
(2011-12-15)
Yeh, Min-Hsin
;
Lee, Chuan-Pei
;
Chou, Chen-Yu
;
Lin, Lu-Yin
;
Wei, Hung-Yu
Conducting polymer materials, i.e., polythiophene (PT), polypyrrole (PPy), and poly(3,4-ethylenedioxythiophene) (PEDOT) were used to prepare counter electrodes (CEs) for quantum-dot-sensitized solar cells (QDSSCs). The QDSSC with PEDOT-CE exhibited the highest solar-to-electricity conversion efficiency (eta) of 1.35%, which is remarkably higher than those of the cells with PT-CE (0.09%) and PPy-CE (0.41%) and very slightly higher than that of the cell with sputtered-gold-CE (1.33%). Electrochemical impedance spectra (EIS) show that this highest conversion efficiency of the PEDOT-based cell is due to higher electrocatalytic activity and reduced charge transfer resistance at the interface of the CE and the electrolyte, compared to those in the case of the cells with other conducting polymers and bare Au. Furthermore, the influences of morphology of the PEDOT film and the charge passed for its electropolymerization on the performance of its QDSSC were also studied. The higher porosity and surface roughness of the PEDOT matrix, with reference to those of other polymers are understood to be the reason for PEDOT to possess higher electrocatalytic activity at its interface with electrolyte. (C) 2011 Elsevier Ltd. All rights reserved.
Efficient bulk heterojunction solar cells based on a low-bandgap polyfluorene copolymers and fullerene derivatives
(2009-09-01)
Huang, Jen-Hsien
;
Li, Kuang-Chieh
;
Wei, Hung-Yu
;
Chen, Po-Yen
;
Lin, Lu-Yin
A low-bandgap polymer (PF-PThCVPTZ) consisted of fluorene and phenothiazine was designed and synthesized. With the donor-acceptor segment, the partial charge transfer can be built in the polymer backbone leading to a wide absorbance. The absorption spectrum of PF-PThCVPTZ exhibits a peak at 510 nm and an absorption onset at 645 nm in the visible range. As blended with [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) as an electron acceptor, narrow bandgap PF-PThCVPTZ as electron donor shows significant solar cell performance. Under AM 1.5 G, 100 mA/cm(2) illumination, a power conversion efficiency (PCE) of 1.85% was recorded, with a short circuit current (J(SC)) of 5.37 mA/cm(2), an open circuit voltage (V(OC)) of 0.80 V, and a fill factor (FF) of 43.0%. (C) 2009 Elsevier B.V. All rights reserved.
Solvent-Annealing-Induced Self-Organization of Poly(3-hexylthiophene), a High-Performance Electrochromic Material
(2009-12-01)
Huang, Jen-Hsien
;
Yang, Chuan-Yi
;
Hsu, Chih-Yu
;
Chen, Cheng-Lun
;
Lin, Lu-Yin
We have systematically studied the self-organization of poly(3-hexylthiophene) (P3HT), an electrochromic material, upon control of the solvent evaporation race. We characterized these polymer films using atomic force microscopy and X-ray diffraction measurements. Well-ordered P3HT structures were developed after solvent annealing; these highly crystalline structures exhibited enhanced electrochromic contrast and reduced resistance within the film, leading to larger coloration efficiencies and faster switching times. The optical contrast (Delta%T), coloration efficiency, and switching time of the P3HT films increased from 54.2%, 182,6 cm(2) C(-1), and 5.3 s, respectively, prior to solvent annealing to 64.8%, 293.5 cm(2) C(-1), and 3.2 s, respectively, after application of the solvent-annealing conditions.
Study on Oxidation State Dependent Electrocatalytic Ability for I-/I-3(-) Redox Reaction of Reduced Graphene Oxides
(2014-01-01)
Yeh, Min-Hsin
;
Lin, Lu-Yin
;
Huang, Tzu-Yen
;
Chuang, Hui-Min
;
Chu, Chih-Wei
The influence of oxidation states on electrocatalytic abilities for I-3(-) reduction is discussed for reduced graphene oxide (rGO), which is a promising catalyst of counter electrodes for dye-sensitized solar cells (DSSCs). The oxidation states of rGO can be controlled via a photothermal reduction process by varying exposure times. The results reveal that the rGO with lower oxidation state shows smaller charge transfer resistance at the electrode/electrolyte interface and better electrocatalytic ability attributed to higher standard heterogeneous rate constant (k(0)) and reasonable electrochemical surface area (A(e)) for I-3(-) reduction, both are quantitatively determined by a rotating disk electrode system using the Koutecky-Levich equation.
Synthesizing highly conductive cobalt sulfide hydrangea macrophylla using long carbon-chain sulfur source for supercapacitors
(2015-01-01)
Chiu, Jun-Ming
;
Lin, Lu-Yin
;
Yeh, Ping-Hung
;
Lai, Chun-Yen
;
Teng, Ke
Cobalt sulfide has attracted much attention as the electroactive material for the supercapacitor (SC) because of its high capacitance and cost-effective features. A novel three-dimensional cobalt sulfide hydrangea macrophylla nanostructure with a thin carbon layer growing on the surface has been successfully synthesized by using a simple one-pot method with the addition of 1-dodecanethiol as the sulfur source connected with long carbon chains. The cobalt sulfide hydrangea macrophylla architecture is composed of several two-dimensional (2D) nanopetals intertwined together and thin carbon layers surrounding the nanopetals. A high specific capacitance (CF) of 324.17 F g(-1) is obtained for the cobalt sulfide hydrangea macrophylla-based SC electrode measured by cyclic voltammetry (CV) at a scan rate of 10 mV s(-1), due to the large surface area for charge accumulation and faradic reactions, as well as the high conductivity for charge transportation respectively benefitting from the 2D nanopetals and the carbon layers. The high CF value achieved in this study opens a window to morphology design for realizing highly effective pseudocapacitors.