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Thomas, Glyn Rees. "Counter electrode materials for electrochromic windows." Thesis, University of Southampton, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.261513.
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Brotherston, Ian David. "Electrochemical characterisation of proposed counter electrode for electrochromic windows." Thesis, University of Southampton, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242301.
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SANGIORGI, NICOLA. "Portable photo-rechargeable device based on Molecular Imprinted Polypyrrole counter-electrode." Doctoral thesis, Università degli Studi di Roma "Tor Vergata", 2016. http://hdl.handle.net/2108/201675.
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In this work a flexible photo-rechargeable device obtained coupling a Dye-Sensitized Solar Cell and a micro-supercapacitor was developed and tested. The energy harvester based on Dye-Sensitized Solar Cell (DSSC) was implemented using an innovative and efficient counter-electrode based on Molecular Imprinted polypyrrole (MIP-PPy). Glycine as a template molecule was found to produce the highest solar cells efficiency when a gel-state electrolyte was used. At the same time, the electrochemical storage unit based on flexible micro-supercapacitor (µ-SC) was studied focusing on the electrodes properties (Zinc Oxide and reduced Graphene Oxide). ZnO as pseudocapacitive electrode was produced and the influence of surfactant molecules introducing during the electrochemical synthesis on specific capacitance and transparency of the obtained film was studied. On the other hand, electrochemically reduced Graphene Oxide (rGO) double layer electrode was prepared and the influence of the deposition time on the electrode properties was studied. The final device was obtained coupling the best ZnO and rGO electrode with an electrolyte gelled with silica or nanoclay. The second one leads to the device with the highest capacitance and cycling stability. Finally, a flexible photo-rechargeable based on DSSC and µ-SC was prepared; the two systems were integrated in the same substrate creating a unique, integrated device. The photovoltage produced by the DSSC under illumination was found to be able to recharge the flexible µ-SC.
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Zheng, Yichen. "Photoanode and counter electrode modification for more efficient dye sensitized solar cells." Thesis, Kansas State University, 2014. http://hdl.handle.net/2097/17841.
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Master of ScienceDepartment of Chemistry
Jun Li
With the increasing consumption of energy and the depletion of fossil fuels, finding an alternative energy source is critical. Solar energy is one of the most promising energy sources and solar cells are the devices that convert solar radiation into electricity. Currently, the most widely used solar cell is based on p-n junction formed with crystalline silicon materials. While showing high efficiency, the high fabrication cost limits its broad applications. Dye sensitized solar cell (DSSC) is a promising low-cost alternative to the Si solar cell, but its efficiency is much lower. Improvements in materials and interfaces are needed to increase the DSSC efficiency while maintain the low cost. In this thesis, three projects were investigated to optimize the DSSC efficiency and reduce the cost. The first project is to optimize the TiO[subscript]2 barrier layers on Fluorine-doped Tin Dioxide (FTO) surface. Two preparation methods, i.e. TiCl[subscript]4 solution treatment and thermal oxidation of sputtered Ti metal films, were employed and systematically studied in order to minimize electron-hole recombination and electron backflow during photovoltaic processes of DSSCs. TiCl[subscript]4 solution treatment method was found to create a porous TiO[subscript]2 barrier layer. Ti sputtering method created a very compact TiO[subscript]2 blocking layer. Two methods showed different characteristics and may be used for different DSSC studies. The second project is to reduce the DSSC cost while maintaining the efficiency by replacing the expensive Pt counter electrode with a novel vertically aligned carbon nanofiber (VACNF) electrode. A large specific electrode surface area (~125 cm[superscript]2 over 1 cm[superscript]2 geometric area) was obtained by using VACNFs. The relatively high surface area, good electric conductivity and the large numbers of active graphitic edges existed in cone-like microstructure of VACNFs were employed to improve redox reaction rate of I[subscript]3[superscript]-/I[superscript]- mediators in the electrolyte. Faster electron transfer and good catalytic activities were obtained with such counter electrodes. The third project is to develop a metal organic chemical vapor deposition (MOCVD) method to coat TiO[subscript]2 shells on VACNF arrays as potential photoanodes in the DSSC system in order to improve the electron transfer. Fabrication processes were demonstrated and preliminary materials were characterized with scanning electron microscopy and transmission electron microscopy. MOCVD at 300 mTorr vapor pressure at 550° C for 120 min was found to be the optimal condition.
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Hartridge, Adrian. "Lanthanide doped ceria thin films as possible counter electrode materials in electrochromic devices." Thesis, University of Warwick, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.367148.
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Yu-HsuanYang and 楊玉軒. "Porous counter electrode based perovskite solar cells." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/47108639978717851080.
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"Effects of Sputtered Platinum Counter Electrode and Integrated TiO2 Electrode with SWCNT on DSSC Performance." Master's thesis, 2011. http://hdl.handle.net/2286/R.I.14369.
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abstract: Dye sensitized solar cells (DSSCs) are the third generation solar cells expected to outperform the first two generations of solar cells with their advantages of comparative higher efficiency and lower manufacturing costs. The manufacturing cost of Dye sensitized solar cells is one fifth of the conventional silicon solar cell. However, DSSCs have problems of low conversion efficiency, stability and reliability. Some effective approaches are required to improve their performance. This paper projects the work related to assessment and verification of the repeatability of the semi-automated fabrication process. Changes were introduced in to the fabrication process to enhance the efficiency and stability. The sealant step in the fabrication process was remodeled to a newer version with an improvement in efficiency from 11% to 11.8%. Sputtering was performed on counter electrode in 30 seconds intervals. Cells were fabricated to assess the performance & time dependent characteristics from EIS experiments. Series resistance increased three times in sputtered Pt electrode as compared to standard platinum electrode. This resulted in the degradation of conductive surface on glass electrode due to heavy bombardment of ions. The second phase of the project work relates to the incorporation of SWCNT on the TiO2 electrode and its effect on the cell efficiency. Different weight loadings (0.1 wt %, 0.2 wt%, 0.4 wt %) of SWCNTs were prepared and mixed with the commercial TiO2 paste and ethanol solvent. The TiO2-SWCNT layer was coated on the electrode using screen-printing technique. Both open circuit voltage and photocurrent were found to have measurable dependence on the TiO2 layer loading. Photo voltage ranged from ~0.73 V to ~0.43 V and photocurrent from ~8 to ~33 mA depending on weight percent loading. This behavior is due to aggregation of particles and most TiO2 aggregate particles are not connected to SWCNT. Transparency loss was observed leading to saturation in the photo current and limiting the light absorption within the TiO2 film.Dissertation/Thesis
M.S.Tech Technology 2011
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Chang, Chih-Chien, and 張志謙. "Study of Multi-layer Structure Working Electrodes and Composite Counter Electrodes for Dye-Sensitized Solar Cell." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/rm96td.
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碩士國立宜蘭大學
化學工程與材料工程學系碩士班
102
The study is to investigate the two parts of working electrode and counter electrode. In the first part, the anatase TiO2 nanoparticles and hollow spherical were prepared by hydrothermal method, then use screen printing method to fabricate active layer, blended layer and scattering layer to compose the optimization multiple structures working electrode. This multiple structures not only can increase the dye adsorption but also the light scattering ability, performance of the current density 17.49 mA/cm2, and the efficiency was 9.24%. In the second part, the fabrication of platinum (Pt) counter electrodes was performed with various preparation methods and different materials. Counter electrodes such as Pt/graphene via screen printing and Pt by sputtering was utilized in DSSCs and their photovoltaic performances were compared. Due to the higher dispersibility of add graphene in the Pt could increased catalytic ability, the Pt/graphene device exhibited a lower electron transport resistance (R1) than Sputter Pt CE device as observed from electrochemical impedance data. The Pt/graphene device exhibited a higher current density 14.20 mA/cm2 and the efficiency of 7.88% , which was relatively higher than Sputter Pt CE (23.90%). The optimum conditions for the two parts of working electrode and counter electrode, the performance of current density 18.52 mA/cm2, and the efficiency can be reached 9.52%.
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Yang, Bing-Hao, and 楊秉豪. "Carbon Nanomaterials as Counter Electrodes for Dye-sensitized Solar Cells." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/37685736843639624234.
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碩士元智大學
化學工程與材料科學學系
99
This dissertation can be qualitatively divided into three parts, (i) influence of 1-D carbon nanotubes and 2-D graphene nanosheets carbon, (ii) mesocarbon microbead-based and (iii) graphene nanosheet with different oxidation levels as counter electrodes for dye-sensitized solar cells. The resulting carbon counter electrodes were characteried by XRD, FE-SEM, HR-TEM, Solar simulator and IPCE test. (i) 1-D carbon nanotubes and 2-D graphene nanosheets carbon as counter electrodes This study examines the dye-sensitized solar cells (DSSCs) equipped with 1-D carbon nanotubes (CNTs) and 2-D graphene nanosheets (GNs) carbon counter electrodes. Imperfect defects were attached to the sidewall or both the ends of the CNTs, and the edges of the GNs were analyzed by X-ray diffraction and Raman spectroscopy. When compared with the GN-based counter electrode, CNT-based counter electrodes showed a better improvement in the incident photon-to-current efficiency and power conversion efficiency of the cells. This enhancement of cell performance can be attributed to the combination of CNT network and spherical graphite bottom layer, favoring dye adsorption, catalytic redox activity, and 1-D charge-transfer path length. Such carbon configuration as counter electrode provides a potential feasibility for replacing metallic Pt counter electrodes. (ii) Mesocarbon microbead-based as counter electrodes The dye-sensitized solar cells (DSCs) equipped with mesocarbon microbead (MCMB)-based counter electrodes were explored to examine their cell performance. Three types of nanosized additives including platinum, carbon nanotubes (CNTs), and carbon black (CB) are well dispersed and coated over microscaled MCMB powders. In the design of the counter electrodes, the MCMB graphite offers an excellent medium that allows charge transfer from the ITO substrate to the dye molecule. The active materials such as Pt, CNT, and nanosize CB act as an active site provider for the redox reaction. Among these counter electrodes, the DSCs fabricated with CB electrode exhibits the highest power conversion efficiency. This improved efficiency can be attributed to the fact that the CB nanoparticles not only offer a large number of catalytic sites but also low charge transfer resistance, facilitating a rapid reaction kinetics. Such design of carbon counter electrode has been confirmed to be a promising candidate for replacing Pt electrodes. (iii) Graphene nanosheet with different oxidation levels as counter electrodes This study examines the performance of dye-sensitized solar cells (DSCs) equipped with graphene nanosheet (GN) counter electrodes with different oxidation levels. A thermal deposition is adopted to adjust O/C atomic ratio and surface oxygen functionalities on graphene sheets. With decreasing the O/C ratio, the GN electrode displays high catalytic activity toward the I3¯/I¯ redox reaction and lower charge-transfer resistance, analyzed by cyclic voltammetry and electrochemical impedance spectroscopy. The DSC fabricated with GN counter electrode also offers an improved incident photon-to-current efficiency and power conversion efficiency, in comparison with that equipped with graphene oxide electrodes. This improvement of cell performance could be attributed to the fact that the GN with 2-dimensional crystal of sp2 carbon and π electrons, acts as a semi-metal or a zero-bandgap semiconductor with remarkable high electron mobility.
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Jung-CheTsai and 蔡榮哲. "Fabrication of cobalt sulfide nanomaterials for counter electrode in DSSCs." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/50574936146087292723.
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博士國立成功大學
材料科學及工程學系
103
Because of high price of Pt noble metal, it is necessary to investigate new materials to replace the Pt as counter electrodes (CE) of DSSCs for industrial production. In this study, the cobalt sulfide nanomaterials with nanoflake arrays, mesoporous thin films and mesoporous nanotube arrays, respectively, are successfully fabricated on FTO coated glass by difference synthesis technologies including hydrothermal synthesis of Co(OH)2, mesoporous Co3O4 formation from cobalt-chelated chitosan, selective etching of ZnO sacrificial templates and ion-exchange reaction (IER). The mesoporous Co3O4 structures composed of the Co3O4 nanoparticles possess the high surface area and take advantage for further removal of templates and ion-exchange reaction. The mesoporous CoS2 structures are prepared by substitution of S2- for O2- after the IER at 90 ℃ for 4 hours. Morphologies and crystal structures of the CoS2 structures were characterized by SEM, TEM and XRD analyses. Their electrocatalytic properties were determined by electrochemical analyses including cyclic voltammetry (CV) measurement and Tafel polarization. Among all cobalt sulfides, the DSSC assembled with mesoporous CoS2 nanotube array CE achieved a highest power conversion efficiency of 6.13% under AM 1.5 condition, which was comparable to that of 6.04% for the DSSC with Pt CE. It indicates that the mesoporous CoS2 nanotube array can be a low-cost and efficient alternative for the reduction of electrolytes in DSSCs.
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Chao, Hsi-Jung, and 趙璽榮. "Application of Nanocrystals in Photosensitizers and Counter Electrodes of Solar Cells." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/73542073839808781670.
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碩士國立臺灣科技大學
化學工程系
103
In this study, our research focused on two parts. The first part is quantum dot sensitized solar cell (QDSSC) and the second part is dye sensitized solar cells (DSCs). In the first part, we synthesized Cdx:CuInS2 quaternary QDs using a one-pot non-injection approach of alloying CuInS2 with Cd2+. Synthesized high quantum yield QDs optical and electrical properties were analyzed by applying them QDs to solar cell application and cyclic voltaic (CV) measurement. We used UVPL and CV to measure photoluminescence, band gap of QDs respectively. The combined co-sensitization’s concept were used to compare Cd:CIS and Cd:CIS/CdSe(4) QDs photoelectric conversion efficiency (PCE) 1.70 % and 2.86 %, respectively. In other part, we present a facile one step hydrothermal approach for in situ growth of metal selenides on FTO glass. In this part, electrochemical analysis was employed to understand dynamic behavior of metal selenides and Pt counter electrode. In order efficiency development of counter electrodes and replacement of expensive platinum in DSSC, we used a facile one step hydrothermal method to synthesize CoxSe, NixSe and CuxSe counter electrodes. A maximum energy conversion efficiency of 6.53 % was obtained under AM1.5G simulated solar light for the cell fabricated with CoxSe as the counter electrode, which is better than Pt. So Pt can be replaced by cobalt selenide as counter electrode (CE) since it has higher PCE than platinum (Pt). The resulted CoxSe can perform better catalytic activity and low-cost requirement. We used SEM, EDS, EIS, Tafel, CV, J-V curve to analyze counter electrode’s structure, interface characteristic and PCE.
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Lin, Yu-Chang, and 林佑錩. "Buckypapers as Pt-Free Counter Electrodes for Dye-Sensitized Solar Cells." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/93999139851426186260.
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碩士東海大學
物理學系
103
Photoelectrochemical dye-sensitized solar cells (DSCs) have attracted much interest in the field of sustainable green energy. However, their counter electrodes (CEs) usually fabricated by the noble metal Pt. To obtain the alternative Pt-Free CEs for DSCs is desirable for the wide deployment of DSCs. Buckypapers (BPs) are prepared in the random and highly interpenetrative configuration of multi-walled carbon nanotubes (MWCNTs), and it has high porosity and conductivity. In this study, BPs are unitized as the CEs for DSCs. From the results of electrochemical impedance spectroscopy (EIS) analysis, the charge transfer rate (fct) of BP-DSC (9357 Hz) is greater than that of Pt-DSC (698 Hz) and the recombination rate (frec) of BP-DSC (1.1 Hz) is lower than that of Pt-DSC (1.7 Hz), indicating the BP-CE provides an efficient reduction and suppresses the recombination in DSC. For the results of cyclic voltammetry (CV), the reduction current [I(Red1)] of BP electrode (-0.956 mA) is greater than that of Pt electrode (-0.083 mA). The results of EIS and CV measurement reveal that the reduction reaction of BP electrode is improved because of its extreme electroactive surface area, and this improvement suppresses the recombination rate in DSCs. Accordingly, BP-DSCs show a high open-circuit voltage (Voc) and fill factor (FF) in power-dependent J-V characterization. As the results, BP-DSCs exhibit a higher enhancement in PCE than that of Pt-DSCs and show the PCE comparable to Pt-DSCs under 100 mW/cm2 illumination.
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Hsieh, Ting-Hsuan, and 謝定軒. "Dye Sensitized Solar Cells with Cobalt Derivatives as Counter Electrodes Applications." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/21887347527172219659.
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碩士國立聯合大學
光電工程學系碩士班
102
In this thesis, we replace the traditional platinum with cobalt composite material as the counter electrodes of dye-sensitized solar cells (DSSCs). Different kinds of cobalt derivatives, VB12, Co12, and Co15 were prepare and each of them were optimums by controlling the solution concentration, film thickness, and annealing temperature. The devices showed the power conversion efficiency of 1.24% with 0.023M of Co12 and 1.06% with 0.019M of Co15 under proper fabrication conditions. In order to improve the conductivity of the cobalt counter electrodes thus enhance device efficiency in further, carbon black was mix with the cobalt derivatives. The device with the counter electrode of 2M carbon black mixed with 0.023M (Co12) showed the power conversion efficiency of 3.34% and that mixed with Co15 showed the efficiency of 2.76%. After the optimization of the concentration of carbon black and film thickness, the device showed the efficiency of 7.14% with the counter electrode of 0.019M (Co15) mixed with 1M carbon black. Furthermore, another new cobalt derivative CoCB which is directly synthesized by VB12 and carbon black was introduced as the counter electrode, the optimized device showed the power conversion of 7.38% with the JSC of 18.65 mA/cm2, VOC of 0.73 V, and fill factor of 0.51. Further improvement was done by mix the CoCB with the conduction polymer, PEDOT:PSS. The device with CoCB-PEDOT:PSS (3:1) film as the counter electrode showed the efficiency of 7.38% with the JSC of 16.50 mA/cm2, VOC of 0.71 V, and fill factor of 0.61. These result indicated that the potential of cobalt derivatives serve as the counter electrodes in high efficiency DSSCs.
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YANG，SHUN-HAN and 楊順涵. "Study of Graphene as Counter Electrode in Dye Sensitized Solar Cell." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/33387993097194377342.
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碩士南臺科技大學
光電工程系
105
In older to search for an efficient and low cost counter electrode in a dye-sensitization solar cell (DSSC), graphene thin films printed onto TCO (transparent conductive oxide coated) glasses were conducted to explore the performance of the counter electrode in a dye-sensitization solar cell. The correlation between annealing parameters of graphene films and the efficiency of DSSCs has be investigated systematically. In this study, the graphene thin films have been printed on FTO glasses using doctor blade method. The experimental parameters include graphene thin film thickness, annealing temperatures and annealing environments. The morphologies and microstructure of graphene thin films were investigated by scanning electron microscopy (SEM). The sheet resistance of graphene thin films was examined by Hall effect measurement and the degree of crystallinity of graphene thin films was extracted by Raman spectrometry. The result shows that DSSC assembled with graphene thin film annealed under argon at 480℃ has a good power conversion efficiency of 6.075%. It’s revealed that graphene thin film/FTO counter electrodes annealed under argon performed better characteristics than those annealed under atmosphere. The power conversion efficiency of device of graphene system was about 90% of Pt counter electrode.
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Lin, Yi-Ting, and 林意婷. "Electroless deposition of platinum counter electrode for dye-sensitized solar cells." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/46662564659551726639.
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碩士大同大學
化學工程學系(所)
100
In this study, electroless Pt films deposited on fluorine-doped tin oxide (FTO) glass substrates were prepared using a Pt-activated self-assembled monolayer (SAM) as counter electrodes (CEs) in dye-sensitized solar cells (DSSCs). First, the mechanism for the formation of Pt-activated SAM on FTO glass substrate was examined using X-ray photoelectron spectroscopy analyses. Second, the effects of the pH value and bath composition on the surface morphology, crystal orientation, electrocatalytic activity for I3- reduction reaction of were also investigated. After the optimization with the pH value and composition of deposition bath, the Pt CE prepared by the optimized bath composition of electroless deposition (ELD) at pH 4 with the bath composition consisting of 1.0 mM H2PtCl6．6H2O and 0.5 M C6H5Na3O7．2H2O was found to have a lower Pt loading (15.9 μg cm-2), a higher active surface area (209.71 m2 g-1) and lower charge-transfer resistance (1.92 Ω cm2) than the sputtered-Pt CE. Thus, the cell conversion efficiency of the DSSC based on the ELD-Pt CE achieved 7.07% under an illustration of AM 1.5 simulated solar light, which presented an increase of 13.85% when compared to the that with the sputtered-Pt CE. Meanwhile, its Pt loading was also remarkably reduced as 14.54% of that of the sputtered-Pt CE.
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Yu-ShengChen and 陳宇昇. "Studies of Porous Counter Electrode for Monolithic Dye Sensitized Solar Cells." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/b5ku95.
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Lee, Tzu-Hui, and 李姿慧. "Study of Electrolyte and Counter Electrode in Dye-Sensitized Solar Cell." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/su7y3y.
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碩士國立臺北科技大學
化學工程研究所
97
In this paper, we improve two parts of DSSC, one is electrolyte, and the other is counter electrode. A general experience is that liquid electrolyte will cause difficulty in packaging DSSC for long-term use. In the first part in this study, we introduce PEO into liquid electrolyte, for helping slow down the evaporation velocity of liquid electrolyte, and then we add Oligomer and Nano-particle for improving the electron transfer, and we can improve the efficiency of DSSC. The second part we are supposed to use conducting polymer to replace Pt counter electrode. We investigate what PEDOT and its derivatives influence the on efficiency of DSSC. We test different polymer-electrolyte by I-V curve, and electrolyte are tested at different nano–particle concentrations by EIS, we exam all the conducting polymer with cyclic voltammetry，White Light Interferometers，FT-IR and SEM, in order to identify the property of electrochemistry、chemistry and surface profile of these polymer. Finally, we find out that the efficiency is improved by adding Oligomer and nano-particle; for the other part of this paper, we can find that polymer-electrode not only have the same redox ability with electrolyte, but have the similar efficiency with Pt electrode.
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Wu, Chien-Nan, and 巫建男. "Application of carbon materials as counter electrodes of dye-sensitized solar cells." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/61570193187453647448.
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碩士樹德科技大學
電腦與通訊研究所
97
TiO2 thin films were deposited on ITO/Glass substrates using sol-gel method and spin coating in this study. The rapid thermal annealing (RTA) is used to process TiO2 thin films for drying and sintering. The counter electrode of carbon film is prepared using doctor blade method and than dried at 150℃ for 30min.It exhibits a sheet resistance of 30(ohm/sq.)for carbon film thickness of 50μm. A solution of 0.5M Li+0.05M I2+0.5M 4-tert-butypyridine (TBP) is mixed evenly as electrolyte. The physical characteristics of TiO2 thin films deposited on ITO/Glass substrate with various processing parameters were surveyed by means of the analyses of XRD and SEM. The crystalline of TiO2 film dried at 300℃ was amorphous, while the films annealed 450℃ to 550℃ contained anatase crystallized. Furthermore, the (101) peak is in evidences appearance with the increase of the annealing temperature, and the grain size is also grew up. The grain size of the films is 14nm as the layers of film increased of 20 layers‚which thickness is about 1.66μm. Otherwise‚while the films of 20 layers annealed to 550℃‚the thickness of film decrease to 1.03μm. It can be seen the thickness of films have deduced after annealed. Experimental results reveal that the processing parameters of TiO2 thin film and carbon thin films will influence on the photovoltaic properties.
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Wang, Wei-Yan, and 王偉彥. "A STUDY OF DSSCS BASED ON TCO-PT-FREE FLEXIBLE COUNTER ELECTRODES." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/c62e4f.
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碩士大同大學
化學工程學系(所)
102
In this study, we first utilize the high temperature reflux mode to well mix the CNT and PP and followed by thermal compression to prepare the CNT/PP thin plates as a Pt-free and TCO-free CE for DSSCs. After that, to further carry out the test of materials characterizations and electrochemical activity. Although the cell efficiency of DSSCs using CNT/PP based CEs was still much lower than that of DSSC with Pt/FTO CE, it is showed the excellent sheet resistance and flexibleness. Therefore, we used the CNT/PP to replace the FTO glass as a substrate. In order to enhance the photovoltaic performance, we further deposited PEDOT thin film on flexible CNT/PP plates via electropolymerization method as a PEDOT-CNT/PP CE. From a series of results and discussion, the composites of PEDOT-CNT/PP exhibited excellent electrocatalytic activity and low charge transfer resistance. On the other hand, after the optimization of flexible test, the CNT/PP plate prepared in the ratio of CNT/PP with 43% possessed the highest bending ability. However, the power conversion efficiency of the PEDOT coated on CNT/PP with 43% is 6.09%, which is lower than Pt/FTO CE (6.69%). In the bending characteristics, the composites of PEDOT-CNT/PP showed the excellent potential as a low-cost and flexible composites CE in DSSCs.
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Huang, Wei-Chih, and 黃偉智. "Investigation of nanocomposite materials as counter electrodes for Dye-Sensitized Solar Cells." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/45642960534593753973.
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碩士國立東華大學
光電工程學系
103
Dye-sensitized solar cells (DSSCs) have the advantages of simple process, high efficiency, and low cost. DSSCs have been investigated extensively due to their various features and merits for applications in renewable energy.A typical DSSC consists of a transparent conductive substrate, TiO2 nanoparticles, dyes, an electrolyte, and a platinum (Pt) counter electrode (CE). However, Pt is a rare and expensive metal element and may limit the DSSC applications.As such, replacing the expensive Pt with other materials having the required electrochemical properties for the counter electrode will be much welcome. There are five parts in this thesis. First, NbSe2 nanoparticles, nanorods, and nanosheets were used as the CEs for DSSCs. The electrode properties and device efficiency based on the NbSe2nanostructures were analyzed. Results showed that DSSCs based on NbSe2 nanosheets CEs achieved a conversion efficiency of 7.73%.Second, nanocomposites using graphene hybrid withmarcrocyclic Ni complex were prepared. The electrode properties and device efficiency were analyzed. The DSSCs fabricated with the macrocyclic Ni complex/graphene-based nanocomposite CEsachieved a power conversion efficiency of 8.30%. Third, nanocomposites using graphene hybrid with marcrocyclic Fe complex were prepared. The electrode properties and device efficiency were analyzed. The DSSCs fabricated with the macrocyclic Fe complex/graphene-based nanocomposite CEs reached a power conversion efficiency of 6.29%. Fourth, CEs were fabricated by dopping1S-(+)-Camphorsulfonic acid 99% (CSA) into conducting polymer Poly(o-methoxyaniline) (POMA).The electrode properties and device efficiency were analyzed. The DSSCs fabricated with the POMA-CSA based CEsachieved a power conversion efficiency of 8.71%. Finally, nanocomposites using graphene hybrid with conducting polymerPOMA were prepared. The electrode properties and device efficiency were analyzed. The DSSCs fabricated with the POMA-FGO nanocomposite CEsachieved a power conversion efficiency of 8.58%.
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Kuo, Meng, and 郭孟. "Polyaniline/Ag2S-CdS Nanocomposites for Counter Electrodes of Dye-Sensitized Solar Cells." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/64029173649963298269.
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碩士國立中興大學
化學工程學系所
104
In this study, we prepared Ag2S-CdS nanocomposites (AC11) with equal mole of silver nitrate and caladium acetate by the chemical co-precipitation. SEM and X-ray diffraction meter (XRD) were used to study the morphology of AC11. Moreover, the AC11 and polyaniline (PANI) based nanocomposite PACI was prepared by the in-situ polymerization of aniline in the AC11 containing reaction solution. The AC11 nanoparticles were dispersed in uniform in the PANI based nanorods. In addition, the AC11 and PANI based nanocomposite PACO was prepared by the co-precipitation of AC11 nanoparticles on the surface of the PANI based nanorods. The chemical structure characterization, thermal properties, morphology, and electrochemical behavior of AC11, PANI, PACI, and PACO were studied. The PANI, PACI, and PACO coated FTO glasses were prepared by the spin coating method for the counter electrodes (PANI-S, PACI-S, and PACO-S) of dye-sensitized solar cells (DSSCs). The highest short-circuit current density (Jsc = 12.17 mA/cm2), open-circuit voltage (Voc = 0.72 V) and photo-energy conversion efficiency (η = 5.13%) were obtained for the DSSC fabricated from the PACI coated counter electrode. On the other hand, the PACI coated counter electrode (PANI-D) was prepared by the chemical deposition and in-situ polymerization of aniline in AC11 containing solution. The photovoltaic properties (Jsc = 12.25 mA/cm2 , Voc = 0.63V, and η% = 4.81%) of the PANI-D based DSSC were slightly lower than those of the DSSC fabricated from PANI-S electrode.
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Chang, Chin-yu, and 張晉瑜. "Electrodeposition of molybdenum disulfides as counter electrodes for dye-sensitized solar cells." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/37682754605957283433.
Full textAbstract:
碩士大同大學
化學工程學系(所)
104
In this study, molybdenum disulfide (MoS2) thin films were directly deposited on fluorine-doped tin oxide (FTO) glass substrates via potentiostatic (PS) and pulse-reversal (PR) methods in deposition bath containing [NH4]2MoS4 and KCl at 60℃. The effects of the composition and pH value of the deposition bath on the electrocatalytic activity of the as-prepared MoS2 were systemically investigated. According to the results of Raman spectra, X-ray photoelectron spectroscopy, and scanning electron microscope analyses confirmed that the amorphous structured MoS2 CEs were successfully deposited homogeneous on FTO glass substrates while using PS and PR methods. Firstly, we using the PS mode to find that the addition of KCl into the deposition bath can efficiently enhance the deposition rate of MoS2. However, MoS2-PS9 at -1.0V, MoS2-PS5 at -0.9V have great electrocatalytic activity. Secondly, we proposed a PR mode to further improve the electrocatalytic activity of the electrodeposited MoS2 CEs. It demonstrated an impressive lower charge-transfer resistance (Rct ~18.4Ω). Also, the DSSC using MoS2-PR5 offered outstanding power conversion efficiency of 8.77%, which is as similar as Pt (9.01%) CE. However, MoS2-PR5 have great transmittance, so that the CE offered the power conversion efficiency of 4.82% on the rear, which is as similar as Pt (5.41%) CE. Moreover, it can be a bifacial CE for DSSC. Finally, we employed the optimal deposition condition to deposite MoS2 thin film on ITO-PEN substrate. The as-prepared flexible MoS2-PR5 still demonstrated excellent electrocatalytic activity. The DSSC based on the flexible MoS2-PR5 can achieve the power conversion efficiency of 5.40%.
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Chang, Sheng-Jye, and 張勝傑. "Fabrication of high performance carbon counter electrodes for dye-sensitized solar cells." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/26574800885745939770.
Full textAbstract:
碩士國立高雄應用科技大學
化學工程系碩士班
95
The main purpose of this work is to prepare high-performance counter electrodes for dye sensitized solar cells (DSSC). Various nanoscale carbon materials, have been used for preparing the electrodes with an attempt to substitute the high cost platinum catalyst generally used in the DSSC counter electrode. The effects of carbon materials, binder and coating conditions on the properties of the electrodes have been examined by linear sweep and impedance measurement in I3-/I- acetonitrile electrolytes. Nano-carbon materials including XC-72, R660R, M1300 and BP2000 from Cobat® have been used for preparation of carbon electrodes. The carbon materials were mixed with various binders and coated on stainless steel substrate via doctor-blading method. The results show that full and steady coverage of carbon materials on the substrates could be obtained when 5 to 6 layers of coating were utilized. The binders used in this experiment are Carboxymethyl Cellulose (CMC), Poly(vinylpyrrolidone) (PVP) and Poly (tetrafluoroethylene) (PTFE). The impedance analysis and photoelectric characteristics of DSSC measurement indicate that BP2000 and CMC are the best carbon and binder for the preparation of electrodes, respectively. An optimum content of CMC in the carbon electrode is ca. 23 wt%. In order to further examine the properties of the carbon electrodes, a BP2000 carbon electrode with 23 wt% CMC binder were modified with platinum catalyst via electrodeposition in H2PtCl6 electrolyte solution. However, the Pt modified BP2000 carbon electrode did not have a better properties for the performance of DSSC. The result also shows nano-carbon materials can be competeable materials for DSSC counter electrode. Photovoltaic performances of the DSSC composed of BP2000 carbon counter electrode, R-150 electrolyte and TiO2 photoelectrde provided by Institute of Nuclear Energy Research are VOC= 0.759 V, JSC= 8.12mA cm-2, FF= 52.03% and η = 3.21%.
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龍冠云. "Fabrication of Platinum/Platinum-Graphene Counter Electrodes of Dye-Sensitized Solar Cells." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/zvu5xk.
Full textAbstract:
碩士國立彰化師範大學
機電工程學系所
105
In the thesis, the study of the processes of the platinum and platinum-graphene counter electrodes of the dye-sensitized solar cells (DSSCs) are presented. A spin coater was used for the coating of the platinum and platinum-graphene materials. The fabrication of the platinum counter electrodes, as a function of the spin speed, spin time, and sintering temperature, was studied. The influence of the concentration of the platinum-graphene materials on the characteristics of the DSSCs was investigated. The material analysis of platinum and platinum-graphene counter electrodes was conducted by the scanning electron microscope, the x-ray diffraction, and the Raman spectroscopy. The photovoltaic conversion characteristics of the DSSCs were measured. The best photovoltaic conversion characteristics were attained by a platinum-graphene concentration of 0.15M. The processes of the platinum-graphene counter electrodes have the advantage of low manufacturing costs and demonstrate excellent potential for the DSSCs.
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Cruz, Rui Alberto Teixeira. "Addressing sealing and counter-electrode challenges of dye solar cells towards industrialization." Doctoral thesis, 2013. https://repositorio-aberto.up.pt/handle/10216/87325.
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Guo, Ting-Wei, and 郭庭維. "Application of palladium-carbon on counter electrode of dye-sensitized solar cell." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/3yqkfm.
Full textAbstract:
碩士國立東華大學
材料科學與工程學系
106
The study used of screen printing plate production of titanium dioxide working electrode, and the scattering layer. The experimental working electrode and the scattering layer used small particles of Degussa P25 titania powder and large particles of Degussa P200 titania powder mixed with small particle Degussa P25 titanium dioxide powder, respectively. First of all, to find the best working electrode layer, and then the scattering layer, to try different titanium tetrachloride treatment time to improve the short-circuit current density, the photoelectric conversion efficiency has increased from 6.19 % to 8.33 %. Sequentially, different concentrations of palladium-carbon suspension were added to the platinum counter electrode to find out the optimal concentration to obtain a better counter electrode. The experimental results showed that added a lower concentration of palladium-carbon suspension has helped to increase the short-circuit current density. Short-circuit current has increased from 15.49 mA/cm2 to 16.86 mA/cm2, which has improved the photoelectric conversion efficiency from 8.33 % to 8.61 %.
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Cruz, Rui Alberto Teixeira. "Addressing sealing and counter-electrode challenges of dye solar cells towards industrialization." Tese, 2013. https://repositorio-aberto.up.pt/handle/10216/87325.
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Huang, Yu-Shiu, and 黃昱修. "NaSbS2 bifacial quantum dot-sensitized solar cells with semitransparent NiSe counter electrode." Thesis, 2019. http://ndltd.ncl.edu.tw/cgi-bin/gs32/gsweb.cgi/login?o=dnclcdr&s=id=%22107NCHU5198006%22.&searchmode=basic.
Full textAbstract:
碩士國立中興大學
物理學系所
107
This thesis describes the optimization of the TiO2 photoanode and the fabrication of bifacial illuminated NaSbS2 ternary semiconductor sensitized solar cells with semi-transparent nickel selenide (NiSe) counter electrode. Ni-Se alloys were prepared by the hot-Injection method using oleylamine as the coordinating solvent. By varying the compositions of nickel source and selenium powder, Ni-Se alloyphases of NiSe, Ni3Se4 andNi0.85Se were formed. Sodium antimony sulfide (NaSbS2) ternary semiconductor quantum dots were grown on a mesoporous TiO2 electrode using the successive ionic layer adsorption reaction (SILAR) method. The morphology, composition and structure of NaSbS2 and Ni-Se alloys were characterized by X-ray diffraction, UV-Visible spectroscopy and transmission electron microscope. XRD shows different phases of Ni-Se alloy with average crystalline size of 10-20 nm calculated using Debye-Scherrer formula. High-resolution transmission electron microscope (TEM) images reveal that Ni-Se nanorods ~ 60 nm in length and 10 nm diameter in size are homogeneously distributed on the mesoporous TiO2 electrode. Liquid junction semiconductor-sensitized solar cells were fabricated from the NaSbS2 semiconductor as photoanode with polysulfide electrolyte and Ni-Se alloy as counter electrode. The best cell exhibited a short-circuit density of 13.83 mA/cm2, an open-circuit voltage of 0.44 V, a fill factor of 34,41 % and a power conversion efficiency (PCE) of 2.09 % under 100% sunlight illumination (AM 1.5) and 4.92 % under 10% sun, respectively. When used in bifacial cells with different TiO2 compact layers, the best cell yielded a PCE of about 0.7 % on the front side and 0.05% on the rear side, respectively
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CHOU, YU-CHEN, and 周郁晨. "The Study of Carbon Black as Counter Electrodes in Dye Sensitized Solar Cells." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/71734296264018132878.
Full textAbstract:
碩士國立聯合大學
光電工程學系碩士班
104
In this thesis, we use carbon black (CB) as counter electrodes (CEs) to replace the conventional platinum (Pt) electrodes in dye sensitized solar cells (DSSCs), and optimums the fabrication process in further. The thesis is divided into three parts: (1) the optimization of CB CEs with various concentrations, (2) the optimization of CB (3M) by pre-annealing CB powder, (3) the optimization of pre-annealing CB CEs by using non-working area spin coating method. First, in order to investigate the influence of molecular stacking to the electrical properties of CB CEs, we fabricate CB CEs with various concentrations. The optimization device with CB (5M) with proper fabrication conditions shows the device efficiency of 7.55 %, with the strong enhancement of the short-circuit current (Jsc) and the fill factor (FF). Next, we further improve the electrical properties of CB by pre-annealing CB powder under 600 oC to purify CB and increase the catalyst ability of CB molecules. The molecular stacking of CB also change, result in the increase of surface roughness. The optimization device with 120 minutes pre-annealing CB powder shows the device efficiency of 7.64 % with the reduction of internal resistance and leakage current of the device. Finally, we introduce the non-working area spin coating method to improve the uniformity of CB film after pre-annealing process. The uniformity of CB film is enhanced obviously and thus increases the device efficiency to 7.77 % with 180 minutes pre-annealing CB powder.
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Shih, Chun-Jyun, and 施純鈞. "Investigation of graphene nanocomposite materials as counter electrodes for Dye-Sensitized Solar Cells." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/bgck98.
Full textAbstract:
碩士國立東華大學
光電工程學系
105
Dye-Sensitized Solar Cells (DSSCs) have attracted much attention due to their various merits, such as relatively high efficiencies, simple device structures, easy fabrication, and low cost. These features have made DSSCs attractive for solar energy applications in the face of increasing energy and environmental challenges. A typical DSSC consists of a transparent conductive substrate, a porous thin-film photoelectrode composed of TiO2 nanoparticles, dyes, an electrolyte, and a counter electrode (CEs). Normally, platinum (Pt)is used as the CE material. However, the cost of Pt is relatively expensive. Therefore, developing a low-cost CE to replace Pt electrodes is a meaningful issue for the cost reduction of DSSCs. This study focuses on the investigation of nanocomposite materials of graphene oxide (GO) and transition metal as counter electrodes for DSSCs. There are four parts in this thesis. First, nanocomposite materials of GO and marcrocyclic Mn complex were prepared. The electrode properties and device efficiency of various weight ratio of GO and Mn macrocyclic complex were analyzed. The DSSCs fabricated with the GO/Mn (1:10) CEs achieved a power conversion efficiency of 7.47%, which was higher than that of the Pt counter electrode. Second, nanocomposite materials of GO and marcrocyclic Zn complex were prepared. The electrode properties and device efficiency were analyzed. The DSSCs fabricated with the GO/Zn (1:10) CEs achieved a power conversion efficiency of 7.78 %, which was higher than that of the Pt counter electrode. Third, nanocomposite materials of GO and marcrocyclic Co complex were prepared. The electrode properties and device efficiency were analyzed. The DSSCs fabricated with the GO/Co (1:10) CEs achieved a power conversion efficiency of 7.48 %, which was higher than that of the Pt counter electrode. Fourth, nanocomposite materials of GO and marcrocyclic Cu complex were prepared. The electrode properties and device efficiency were analyzed. The DSSCs fabricated with the GO/Cu (1:10) CEs achieved a power conversion efficiency of 7.61 %, which was higher than that of the Pt counter electrode. The results show that GO/Mn, GO/Zn, GO/Co, and GO/Cu CEs have the potential to replace Pt electrodes.
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Lu, Man-Ning, and 呂曼寧. "Spray-Deposited NiCo2S4 Based Materials As Counter Electrodes For Dye-Sensitized Solar Cells." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/q3xc25.
Full textAbstract:
碩士大同大學
化學工程學系(所)
102
In this study, NiCo2S4 was synthesized via a facile hydrothermal method by nickel chloride hexahydrate, cobalt chloride hexahydrate, and thiourea in aqueous solution and then reacting at 240℃, 12h. Subsequently, reduced graphene oxide (RGO) was synthesized by chemical exfoliation and hydrothermal reduction treatment. In the hybrid NiCo2S4/RGO materials, the different ratios (2, 5, 10 wt%) of RGO sheets were mixing with NiCo2S4 particles in ethanol. According to X-ray diffraction (XRD), Raman spectrum, and scanning electron microscope (SEM) confirmed that the NiCo2S4 particles and RGO were successfully synthesized and mixed homogeneous. As a result, the ratio of RGO hybrid into NiCo2S4 particles could be effectively controlled, which is crucial for RGO achieving of high electron transfer and electrocatalytic activity of NiCo2S4 particles compared to the conventional Pt counter electrode (CE). Therefore, the dye-sensitized solar cell (DSSC) assembled with hybrid NiCo2S4/RGO-2wt% exhibited the highest catalytic activity and the best conductivity. Moreover, the NiCo2S4/RGO-2wt% CE demonstrated an impressive lower electrode/electrolyte charge-transfer resistance (Rct 0.35 Ω). Also, the DSSC using NiCo2S4/RGO-2wt% as CE offered outstanding power conversion efficiency of 8.04%, which is much higher than NiCo2S4 (7.03%) and Pt (7.80%) CEs.
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Li, Chun-Ting, and 李君婷. "Dye-sensitized Solar Cells:Study of Pt-free Counter Electrodes and Iodide-free Electrolytes." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/a2622n.
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博士國立臺灣大學
化學工程學研究所
103
This dissertation aimed to systematically develop Pt-free counter electrodes (CEs) and to design a novel iodide-free electrolyte for the dye-sensitized solar cells (DSSCs) with low-costs and highly cell efficiencies (η’s). This dissertation is divided into two parts: (1) Pt-free CEs (Chapter 3~Chapter 7) and (2) iodide-free electrolyte (Chapter 8). In the case of Pt-free CEs, we aim to reduce the costs of the DSSCs using various electro-catalysts for completely replacing the expensive Pt via the simple, non-vacuum, and low-cost fabrication processes. Accordingly, three types of Pt-free composite films were studied using a standard iodide electrolyte. (I) Transition metallic compound-type CEs, including the composite film of TiS2/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (TiS2/PEDOT:PSS) in Chapter 3, the composite films of Si3N4/PEDOT:PSS, SiO2/PEDOT:PSS, SiS2/PEDOT:PSS, SiSe2/PEDOT:PSS in Chapter 4, and the composite films of Zn3N2/PEDOT:PSS, ZnO/PEDOT:PSS, ZnS/PEDOT:PSS, ZnSe/PEDOT:PSS in Chapter 5, were indivitually investigated. In a composite film, the transition metallic compound nanoparticles were separately used to provide attractive electro-catalytic abilities and large active areas for I3- reduction; among those NPs, TiS2, Si3N4, SiS2, SiSe2, Zn3N2 and ZnSe were applied in DSSCs for the first time. Among them, the cell with Zn3N2/PEDOT:PSS CE reached a higher η than that of Pt-based cell. (II) Carbonaceous-type CEs, i.e., the composite films of nano-porous carbon black nanoparticles/ sulfonated-poly(thiophene-3-[2-(2-methoxyethoxy)-ethoxy]-2,5-diyl) (CB NPs/s-PT), were investigated in Chapter 6 to provide large surface area, fast eletrolyte penetratoin, and rapid reaction rate for I3– reduction. When a composite film contains 5 wt% CB NPs, the pertinent DSSC reached best η of 9.02%, which is even higher than that of Pt-based DSSC. The s-PT is introduced as a novel thiophene-based water-soluable conducting polymer for CE in DSSC for the very first time. Under weak sunlight, the cell with CB NPs/s-PT composite CE still maintains good performance, indicating its good compatibility at both outdoor or indoor electronics. (III) Conducting polymer type CEs, including poly(3,4-ethylenedioxythiophene) (PEDOT) and six different ionic-liquid-doped PEDOT films were systematically investigated in Chapter 7. Six different ionic liquids containing three imidazolium cations with different alkyl chains (–C2H5, –C6H13, –C10H21) and four anions (BF4−, PF6−, SO3CF3−, TFSI−) were used as the chemical dopants to increase the surface area of PEDOT films and to ehance the conjugation of the PEDOT films, respectively. Among them, the cell with HMIPF6-doped PEDOT and HMITFSI-doped PEDOT CEs reached higher η’s than that of Pt-based DSSC. In brief, this dissertation explores four Pt-free composite films of Zn3N2/PEDOT:PSS, HMIPF6-doped PEDOT, HMITFSI-doped PEDOT, and CB NPs/s-PT are a promising substitutions of Pt due to their outstanding properties, i.e., good electro-catalytic ability for I3– reduction, low-cost, simple preparation process, and easy for large-scale production. In the case of iodide-free electrolyte, we designed a novel dual-channel ionic liquid compound (Chapter 8), 1-butyl-3-{2-oxo-2-[(2,2,6,6-tetramethylpiperidin-4-yl)amino]ethyl}-1H-imidazol-3 -ium selenocyanate (ITSeCN), to further improve the cell effiency of DSSCs. ITSeCN is designed to contain dual redox channels of imidazolium-functionalized TEMPO (cationic redox mediator) and selenocyanate (anionic mediator). Thereby, the ITSeCN shows the favorable redox natures, which gave more positive standard potential, larger diffusivity, and better kinetic heterogeneous rate constant than those of iodide. To further investigate a suitable electro-catalytic material for triggering the redox of ITSeCN mediator, several materials were used: (1) Pt (metal type), (2) PEDOT (conducting polymer type), (3) CoSe (transition metallic compound type), and (4) carbon black (carbonaceous type) films were chosen to represent four types of electro-catalytic materials in DSSCs. Finally, the DSSCs with PEDOT and CoSe CEs achieved better performance than that of the Pt-based DSSC. Therefore, it can be infered that the transition metallic compound type CEs would be more suitable for our new synthesized-ITSeCN mediator than the others.
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Ting-WeiChang and 張庭瑋. "Fabrication of Platinum/Carbon Black Composite Counter Electrodes for Dye-Sensitized Solar Cells." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/72799424212223016974.
Full textAbstract:
碩士國立成功大學
化學工程學系
102
The main purpose of this study is to replace platinum counter electrode prepared by sputter technique. This research includes two parts: (1) Fabrication of carbon black counter electrodes by doctor blading and (2) Preparation of platinum/carbon black (Pt/CB) counter electrodes by polyol reduction. In part.1, the results show that under 350oC heat treatment, the performance of carbon black counter electrodes has strong relationship with carbon black content. Increasing the carbon black content from 8wt% to 15wt% can enhance the electro-activity of counter electrodes, and reduce the charge transfer resistance (Rct) between carbon black/electrolyte interface to 6.65 ohm x cm2. Under this heat treatment condition, the best power conversion efficiency is 6.68%. Compared to the results obtained under 350 oC heat treatment, elevating heat treated temperature to 450 oC can improve electro-activity of counter electrodes significantly, and decrease Rct to 0.44 ohm x cm2. Applying the carbon counter electrodes on DSSC, the best power conversion efficiency 8.35% can be achieved, which is comparable to 8.38% cell efficiency obtained by using sputtered-Pt as counter electrode. In part.2, the results show that the size of platinum nanoparticles synthesized on carbon black by polyol reduction is 2~5nm. Increasing the number of Pt/CB layer can enhance the electro-activity of Pt/CB composite counter electrodes, and decrease the charge transfer resistance at the electrode/electrolyte interface. Besides, reducing the binder concentration of the paste has positive effects on counter electrode performance. Appling the Pt/CB counter electrodes containing low binder concentration, the low Rct 1.44 ohm x cm2 can be obtained, and the best cell efficiency 8.06% can be achieved, which is close to 8.17% by using sputtered-Pt as counter electrode.
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Cheng, Cheng-En, and 鄭承恩. "Applications of Carbon-Based Nanomaterials as Counter Electrodes for Dye-Sensitized Solar Cells." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/52243073546047030282.
Full textAbstract:
博士國立交通大學
光電工程研究所
104
In the thesis, carbon-based nanomaterials are applied to the counter electrodes (CEs) for dye-sensitized solar cells (DSCs) to reduce the consumption of Pt. The applied carbon-based nanomaterials to CEs include graphene, graphene oxide (GO), and buckypaper (BP). Because of storage limitation of Pt, the cost of DSC manufacturing is increasing. Carbon is an abundant element in the Earth’s crust, and carbon-based nanomaterials have lots of excellent electrical, optical, and electrochemical properties. They exhibit great potential to reduce the Pt consumption in DSCs. In addition to developments of low Pt-loading CE with carbon-based material, the photovoltaic performance and charge dynamics of DSCs with graphene, GO and BP-incorporated CEs are investigate to understand the influences of these carbon-based nanomaterials. The Pt-C composite can reduce the contact resistance of Pt/fluorine-doped tin oxide (FTO) interface, resulting in the enhancements of short-circuit current density and power conversion efficiency of DSC with Pt/few-layer graphene CE (DSCPt/FLG). Solution-processable GO provides a low-cost method to prepare large-quantity and high-transparent carbon source. Pt/GO composites are developed as the high-transparent and high-efficient CEs for bifacial DSCs. DSCPt/GO exhibits the better bifacial photovoltaic behaviors because of the outperformed PCE under rear illumination, attributing to the efficient I3- reduction ability of Pt/GO composite. The solution-processable BP is fabricated with entangled multi-walled carbon nanotubes, providing extreme electroactive surface area for I3- reduction. BPs can increase the I3- reduction rate at CE and suppress the charge recombination at photo-anodes. By applying BP, the DSCBP present a comparable performance to DSCPt, and the Pt-free DSCs are achieved. Accordingly, by applications of graphene, GO, and BP, the Pt consumption in DSCs can be reduced by 75%, 80%, and 100%, respectively. According the experimental results, it is found that the electrocatalytic ability and dimension of carbon-based nanomaterials are important. The naturals of carbon-based nanomaterials lead to the worse electrocatalytic ability to I3- reduction. Therefore, the dimension of CEs becomes critical. The 3-dimensional BP demonstrates the large electroactive surface area can compensate the degradation of electrocatalytic ability, which results in the comparable performance to DSCPt. On the other hand, the low-cost CE manufacturing with inexpensive material can be realized by the solution-processable GO and BP, whereas the complex manufacturing is required to synthesize graphene. Pt consumption is a foreseeable cost issue in DSC deployments. This research demonstrates that carbon-based nanomaterials are the potential materials to reduce Pt consumption in DSCs.
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Lee, Kun-Mu, and 李坤穆. "A Study on Dye-Modified TiO2 Electrode, Gel Polymer Electrolyte and Pt-Free Counter Electrode for Dye-Sensitized Solar Cells." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/19070914806518361549.
Full textAbstract:
博士國立臺灣大學
高分子科學與工程學研究所
97
The main purpose of this thesis is to investigate the behaviors of new approaches in electrodes (working and counter), sensitizers and gel polymer electrolytes for dye-sensitized solar cells (DSSCs) and discussing the influences on the cell performance and stability of DSSCs. In the first part of this thesis (Chapter 2 and 3), the optimization of solar energy conversion efficiency of DSSCs was investigated by the tuning of TiO2 photoelectrode’s morphology. Double-layered TiO2 photoelectrodes were designed by the coating of TiO2 suspension incorporated with low and high molecular weight poly(ethylene glycol) as a binder. Among four types of TiO2 electrodes, the P2P1 showed the highest efficiency under the conditions of identical film thickness and constant irradiation. This can be explained by the larger pore size and higher surface area of P2P1 TiO2 electrode than the other materials and these two factors assist for the facile transport of I3-/I- ion couple through the TiO2 matrix. The best efficiency (h) of 9.04% for a solar cell was obtained by introducing the light scattering particles to the TiO2 electrode measured under AM 1.5G. As for the part of low-temperature fabricated DSSC, the TiO2 film with the TTIP/TiO2 molar ratio of 0.08 has the best conduction. Meanwhile, the charge transport resistance at the TiO2/dye/electrolyte interface increased as a function of the MWCNT concentration, ranged from 0.1 to 0.5 wt%, due to a decrease in the surface area for dye adsorption. The DSSC with the TiO2 containing 0.1 wt% of MWCNT resulted in a JSC of 9.08 mA/cm2 and a cell conversion efficiency of 5.02 %. On the other hand, TiO2 film prepared by using binder-free TiO2 paste which developed by Prof. Miyasaka’s group was also used in plastic DSSC to optimal the SJW-E1 dye which synthesized by Prof. Wu’s group. The effects of TiOx buffer layer and co-adsorbents as well as long-term stability of plastic DSSCs were investigated. The TiOx buffer layer not only benefited the adhesion between TiO2 thin film and ITO/PEN substrate but also reduced the electron recombination, resulting in the improvement of the FF and conversion efficiency of cells. The optimized solar cell based on SJW-E1 showed a high efficiency of 6.31 % at 100 mW/cm2 (AM 1.5G), and SJW-E1 based solar cell showed a better stability than that of N719 based after 500 h light soaking test. In the second part of this thesis (Chapter 4), the co-sensitization of dyes for the complementary in the spectral characteristics in plastic DSSCs was investigated. Two co-sensitization systems for the plastic DSSCs, including N719/FL and black dye/FL showed enhanced photovoltaic performances compared with that of each dye individually. The optimal conversion efficiencies of N719/FL and black dye/FL DSSCs reached 5.10 % and 3.78 %, respectively, which were higher than that of individual sensitizers. However, for the system co-sensitized with FL and Chl-e6, the cell performances only lay in between that of each dye. From the EIS analysis, the characteristic frequencies (C.F.) at TiO2/dye/electrolyte interface for N719/FL and black dye/FL are kept the same or lower than that of individual dyes. While for the FL /Chl-e6 co-sensitized DSSCs, the C.F. were higher than that based on only FL, indicating that they had shorter electron lifetime in the TiO2 electrode after co-sensitization. In the third part of this thesis (Chapter 5), two kinds of gel polymer electrolytes were developed and used in DSSCs. At the beginning, it was found that the donor number of solvent in electrolyte is the one of the key factors that effect the photovoltaic performance of DSSC. Meanwhile, the quasi-solid state DSSCs were fabricated with polyvinyidene fluoride-co-hexafluoro propylene (PVDF-HFP) in methoxy propionitrile (MPN) as gel polymer electrolyte (GPE), tetrabutylammonium iodide/iodine as redox couple, 4-TBP as additive and nano-silica as fillers. The energy conversion efficiency of the cell with 5 wt% PVDF-HFP is comparable to that one obtained in liquid electrolyte system. Solar cell containing PVDF-HFP with 0.8 M of TBAI and 0.12 M of I2 shows maximum photocurrent. Moreover, the addition of 1wt% nano-silica is found to improve the at-rest durability and the performance of the solar cell. A photocurrent of 14.04 mA/cm2, a VOC of 0.71 V and an overall conversion efficiency of 5.97 % under 100 mW/cm2 irradiation was observed for the best performance of a solar cell in this work. On the other hand, the ionic conductivities and performances of DSSCs of GPEs prepared by in situ polymerization with different cross-linkers were investigated. The poly(imidazole-co-butylmethacrylate)-based GPE containing the B4Br cross-linker showed a higher ionic conductivity, due to the formation of micro-phase separation that resulted in an increase of ion transport paths in the GPE. Moreover, a co-adsorbent, (4-pyridylthio) acetic acid, co-adsorbed with N3 dye on the TiO2 electrode not only reduced dye aggregation, but also reacted with the cross-linkers in the GPE at the TiO2/GPE interface after gelling, thus the value of JSC significantly increased from 7.72 to 10.00 mA/cm2. In addition, in order to reduce the ionic diffusion resistance within the TiO2 electrode, incorporation of monodispersed PMMA in the TiO2 paste was considered. With the optimal volume ratio of PMMA/TiO2 (v/v = 3.75), the micro-porous TiO2 electrode exhibited larger pores (ca. 350 nm) uniformly distributed after sintering, and the ionic diffusion resistance within the TiO2 film could significantly be reduced. The cell conversion efficiency increased from 3.61 to 5.81% under illumination of 100 mW/cm2, an improvement of ca. 55 %. In the fourth part of this thesis (Chapter 6), a series of poly(3,4-alkylenedioxythiophene) counter electrodes prepared by electrochemical polymerization on the fluorine-doped tin oxide (FTO) glass substrate were incorporated in the platinum-free DSSCs. Cells fabricated with a PProDOT-Et2 counter electrode showed a higher conversion efficiency of 7.88 % compared to cells fabricated with PEDOT (3.93 %), PProDOT (7.08 %), and sputtered-Pt (7.77 %) electrodes. The FF was strongly dependent on the deposition charge capacity of the PProDOT-Et2 layer, but the aggregation of PProDOT-Et2 in higher deposition capacities (> 80 mC/cm2) resulted in decreases in JSC and the cell conversion efficiency. Incorporating the best ProDOT-Et2 film (40 mC/cm2) as the counter electrode in plastic DSSC was compared and showed similar tendency as mentioned above. The cell fabricated with a PProDOT-Et2 counter electrode showed a higher conversion efficiency of 5.20 % compared with that fabricated with sputtered-Pt (5.11%) electrodes under the illumination of 100 mW/cm2 (AM 1.5G).
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Lan, Yu-Chuan, and 藍鈺荃. "Application of Polyaniline Composites at Flexible Counter Electrode of Dye Sensitized Solar Cells." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/42726877800691664024.
Full textAbstract:
碩士國立臺灣大學
材料科學與工程學研究所
104
The main idea of this thesis was to fabricate a flexible and low-cost counter electrode for liquid state dye sensitized solar cells. Three methods were applied---chemical deposition, electrochemical polymerization, and chemical-electrochemical polymerization. We used scanning electron microscopy, thermogravimetry analysis, cyclic voltammetry, four-point probe, etc. to characterize of PANi/graphite composite. We also conducted photovoltaic tests, electrochemical impedance spectroscopy, etc. to observe the device performance. For chemical deposition, we adopted a new dip coating method. Different reaction time was set, which was 1.0, 1.5, 2.0, 2.5, and 3.0 minute. Two groups---1 and 2-layered PANi on Graphite composites---were applied in DSSCs. The DSSC with counter electrode of 1-layered PANi by 1.5 minute has the best performance with power conversion efficiency (PCE) of 6.16 ± 0.229 %, short circuit current density (Jsc) of 16.1 ± 0.0777 mA/cm2, open circuit voltage (Voc) of 0.697 ± 0.0238 V, and fill factor (FF) of 0.571 ± 0.0369. For electrochemical polymerization, there are four groups---PANi, PANi/CNT, PANi/Graphen, and PANi/CNT/Graphene all on graphite substrate---prepared by different reaction time, which was 25, 50, 75, 100, and 125 second. PANi/CNT/Graphene on graphite substrateby 75 second has the highest PCE of 6.34 ± 0.122 %, with Jsc of 12.9 ± 0.0570 mA/cm2, Voc of 0.692 ± 0.0122 V, and FF of 0.674 ± 0.00470. Generally, the DSSCs with CNT or/and Graphene in PANi/Graphite substrate have improved PCE and performance. For chemical-electrochemical polymerization, 1-layered PANi by 1.5 minute was deposited on the counter electrode followed by electrochemical polymerization of PANi with different reaction time as mentioned previously. The DSSCs with PANi followed by PANi/CNT on graphite substrate by 50 second has the highest PCE of 5.35 ± 0.0981 %, with Jsc of 13.0 ± 0.0901 mA/cm2, Voc of 0.694 ± 0.0281 V, and ff of 0.574 ± 0.0185. From the decreasing Voc in I-V curves with reaction time and voltage decrease in hysteresis diagrams, we proposed the possible existence of capacity of PANi in DSSC system, which would impose large impact on the performance of DSSCs. The capacity effect might come from change of oxidation state of PANi. The electrons from external circuit would reduce the protonated emeraldine salt which is at medium oxidation state. Besides, as reaction time for PANi gets longer, the fiber structure interweaves into a network, which imposes steric hindrance for the redox couple (iodide/triiodide) in the electrolyte and thus decrease the reduction rate of triiodide. Although more surface area is created as PANi grows more complexly, the small pores of the network structure prevent redox couples from diffusing into the inside of PANi and undergoing redox reaction. Capacitance effect builds up a reverse potential to the DSSC. Under illumination, Voc and Jsc of DSSCs with PANi as the counter electrode feature a descending tendency with increasing reaction time of PANi.
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Tsai, Jia-Shan, and 蔡佳珊. "Microwave synthesized metal sulfide as counter electrode for quantum dots-sensitized solar cells." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/84757732802883631509.
Full textAbstract:
碩士國立臺灣科技大學
化學工程系
104
In this study, microwave assisted synthetic route was applied for rapid, facial and effective synthesis of counter electrode(CE) for quantum dots-sensitized solar cells(QDSSCs) .Moreover, it is applied for in situ deposition of metal sulfides on the CE, shorten the process time and avoids post treatments. Different metal sulfide CE(CuS, NiS, CoS2, PbS) and aqueous CuInS2/In2S3 quantum dots (QDs) are synthesized by using rapid microwave assisted synthesis approach. The CuInS2/In2S3 QDs photoanode with the CuS CE exhibits champion of short circuit current density (Jsc) of 26.76 mA/cm2, open voltage (Voc) of 650 mV and power conversion efficiency(PCE) of 8.32% at one sun (AM 1.5 G, 100 mW/cm2). Electrochemical impedance spectroscopy (EIS), Tafel and cyclic voltammetry (CV) measurement was employed to understand electro dynamic behavior of metal sulfide CE. Analysis of the data shows that CuS CE performs high electrocatalytic activity towards polysulfide reduction compared with other metal sulfide CE.
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Chung, Yung-Pin, and 鍾永彬. "Synthesis of highly conductive graphene materials for dye-sensitized solar cells counter electrode." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/75618204385612454020.
Full textAbstract:
碩士中原大學
化學研究所
100
In this study, preparation of graphene thin film electrode through graphite oxide was studied. First, multi-layer stacking of graphite was oxidized using sulfuric acid and potassium permanganate for 24h. After oxidation, the solids obtained were dried by freeze-drying and coating on glass substrate, then heat treatment at 650 oC was used to reduce the GO to graphene. PEG, PEO, PVP, Terpineol were used as the binder for reforming graphene into films. It shows that the PEG-made film achieves lower resistance, higher light transmittance than those of the other three binders. The efficiency of DSSC using PEG-made grahene electrode is around 85% of those using Pt-based electrode. At the beginning of this study, the thin-film resistance of graphene electrode is about 100-30 Ω/sq, The graphene was also suffered from the electrolyte, that is the film and substrate will be unstable when liquid electrolyte was present. When the glass substrate was modified using some polyelectrolytes, the resistance of graphene films go down to 5-10 Ω/sq. In the mean time, the efficiency of DSSCs using the modified graphene film electrode can achieve 90% of those using Pt-based electrode or even better. Finally, the catalytic ability of graphene, though is no better than platinum, there edges result more amount of the catalytic sites for electron transfer. Taking these results into account, the catalytic capability of graphene can be quite compatible to that of platinum, making this material a good alternative to platinum as a counter electrode for a high performance DSSC.
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Wang, Hsin-Pei, and 王馨珮. "The Research and Development of the Counter Electrode in Dye-sensitized Solar Cells." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/2pnfn7.
Full textAbstract:
碩士國立臺北科技大學
材料科學與工程研究所
96
This research is mainly concerned with replacement of platinum used as a catalyst layer of dye-sensitized solar cells with diamond like carbon (DLC). The DLC films were grown on indium-tin-oxide coated glass substrates by using cathodic arc deposition. Surface and cross-section layers of this catalyst were observed with scanning electron microscope; sheet resistance of the catalyst layer was measured by a four-point probe. The characteristic redox catalysis of I-/I3- is observed and assessed with cyclic voltammetry (CV). We expect to improve the photoelectric conversion efficiency and reduce the cost of the solar cells by using DLC. The performance of photoelectrochemical response by using DLC as counter electrode was also evaluated in this study. New procedures for the growth of different films are presented in this study. The deposition parameters for counter electrodes are changed and four different counter electrodes namely, ITO/Pt/DLC(n-type), ITO/Cr/DLC, ITO/Cr/DLC(n-type)/Pt, and Glass/Cr/DLC(n-type)/Pt from ITO/Pt are prepared. First, the counter electrode, which consists of ITO/Pt yields low resistance and the efficiency is about 3%. For the ITO/Pt/DLC(n-type), when different N2 concentrations (0, 5, 10, 30, 60 sccm) are doped, the results with N2 of 10 sccm, gave the best conversion efficiency of about 1.8%. Second, the counter electrode, which consists of ITO/Cr/DLC, and DLC is deposited on top of Cr (DLC deposition time is 5, 10.5, 12 mins), the cell efficiency is 1.5%. Third, the counter electrode, which consists of ITO/Cr/DLC (n-type)/Pt (Pt deposition time is 5, 10 seconds), exhibited an efficiency of 3.3%. After replacing ITO glass substrate with simple glass substrate, i.e Glass/Cr/DLC (n-type)/Pt structure, the photoelectric efficiency could reach to 3.2%, indicating that we can successfully replace ITO glass substrate with simple glass plate. CV measurements which are characteristic of catalysis for electrodes ITO/Cr/DLC/Pt and Glass/Cr/DLC(n-type)/Pt gave similar results like ITO/Pt, but they are better than ITO/Cr/DLC and ITO/Pt/DLC. The conduction bands and valance bands of films determined for Glass/Cr/DLC(n-type)/Pt are correlated with ITO/Pt. It can change I3- to I- because of the Pt layer directly in contact with electrolyte, but the catalysis characteristics and electric conductivity of DLC are relatively low.
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Chen, Chun-Hsiao, and 陳俊孝. "Carbon Nanotubes Growth by PECVD as Counter Electrode for Dye-Sensitized Solar Cells." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/meztz2.
Full textAbstract:
碩士國立臺灣大學
化學工程學研究所
97
The main part of this dissertation is the study of carbon canotubes growth by DC-PECVD as counter electrode for dye-sensitized solar cells. At temperature 350℃, it will grow different types of CNTs by controling nickel metal catalyst layer from 5 to 40nm and with direct-current power , 100W and 150W. Structure and ingredients of the CNTs were studied by SEM. With regard to the producing method of working electrode, adsorbing dye molecules（N719 1.0×10-4M） on the TiO2 thin film；The liquid electrolyte 0.5M LiI, 0.05M I2, 0.5M tert-butyl pyridine (TBP) dissolving in Acetonitrile was used throughout this work；and then we used different types of CNTs on plate as counter electrode. Efficiency of DSSCs was measured by Photovoltaic Measurement System. The employment of different CNTS as counter electrodes was studied. CNTs growing on a 5nm nickel metal catalysis and with 150W direct-current power reached a efficiency of 1.9%. We found that to be the best choice for counter electrodes.
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Anwar, Hafeez. "Precious Metal-free Dye-sensitized Solar Cells." 2013. http://hdl.handle.net/10222/42686.
Full textAbstract:
Exploring new technologies that can meet the world’s energy demands in an efficient and clean manner is critically important due to the depletion of natural resources and environmental concerns. Dye-sensitized solar cells (DSSCs) are low-cost and clean technology options that use solar energy efficiently and are being intensively studied. How to further reduce the cost of this technology while enhancing device performance is one of the demanding issues for large scale application and commercialization of DSSCs. In this research dissertation, four main contributions are made in this regard with the motivation to reduce further cost of DSSC technology. Firstly, ~10% efficiencies were achieved after developing understanding of key concepts and procedures involved in DSSCs fabrication. These efficiencies were achieved after step-by-step modifications in the DSSC design. Secondly, carbon nanotubes (CNTs) were successfully employed as an alternative to Pt in the counter electrodes of DSSCs. DSSCs fabricated with CNTs were ~86% as efficient as Pt-based cells. Non-aligned CNTs were successfully grown using four different CVD methods and finally, multi-walled vertically aligned CNTs (MW-VACNTs) were synthesized using water-assisted chemical vapor deposition (WA-CVD). Thirdly, carbon derived from pyrolysis of nanocrystalline cellulose (NCC) was successfully employed in counter electrodes of DSSCs instead of Pt. DSSCs with NCC were ~58% as efficient as Pt-based DSSCs. Fourthly, novel organic metal-free dyes were designed and employed instead of commonly used Ru-based dyes. DSSCs with these novel sensitizers were ~62% as efficient as those using the conventional Ru-based dyes. Characterization techniques including current-voltage measurements, scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS), cyclic voltammetery (CV), thermogravimetric analysis (TGA), small angle x-ray scattering (SAXS), atomic force microscopy (AFM) and x-ray photoelectron spectroscopy (XPS) were used.
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Lai, Meng-Yi, and 賴盟依. "The study of using Cu2ZnSnS4 structure as counter electrode for Dye-Sensitized Solar Cells." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/51407513363733904451.
Full textAbstract:
碩士國立臺灣科技大學
化學工程系
103
In this work, we have synthesized Cu2ZnSnS4 (CZTS) nanocrystal by solvothermal method and it is used as a counter electrode in the place the Platinum in dye-sensitized solar cells (DSSCs). CZTS is one of the promising materials to replace the platinum due to the earth abundant, low cost and non-toxic material. The synthesized CZTS nanocrystals were characterized by XRD, Raman, XPS, UV-vis spectra, FE-SEM and TEM. The obtained results were compared with reported results and listed out the advantages of our results. In addition, it’s confirmed that CZTS nanocrystals could be acted as photocatalyst in DSSCs. In this work, we have used both single-side and double-side illumination to measure the performance of DSSC devices. The result of short-circuit current density for double-side was increased about 24.75% when compared to the single-side illumination. Also we studied the different concentration of electrolyte that contain I- and I3- to find out the photocatalytic activity of CZTS nanocrystal. Finally, we have standardized the concentration of electrolyte which can provide the highest short-circuit current density and also proved the stability of CZTS nanocrystal as counter electrode in DSSCs.
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Hsu, Shih-shang, and 徐世商. "Platinum counter electrode and TiO2 photoelectrode characteristics of dye-sensitized solar cell for efficiency." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/87242594781745774451.
Full textAbstract:
碩士國立臺南大學
電機工程學系碩士班
100
This study was divided into two parts. In the first part, the platinum counter electrode was prepared by electrodepositing platinum thin film on the ITO conductive glass sheet, and its application in DSSCs has been studied. In the second part, effects of using in oxygen atmosphere various annealing time of TiO2 nanotubes photoelectrode were studied. The nano-structure platinum thin films not only have higher transmittance (71%) than thicker platinum thin films, but also possess lower charge transfer resistances. Using the basis of electrochemical impedance spectroscopy (EIS) analyze the impedance changes of different thickness of Pt films. The results show that a lower charge transfer resistance (RPt 5.4Ω/cm2), higher electro-catalytic activity and good transparency counter electrode was obtained after depositing the Pt thin film on it. As exposure to the sunlight simulator under AM1.5, the best results of Voc, Jsc , FF, DSSC efficiency of the cell are 0.71V, 2.74mA/cm2, 0.63 and 1.21% individually. The results showed that textured platinum films can effectively enhance the catalytic activity of electrode surface and increase the reduction capacity of I3- ion at the Pt / electrolyte interface. It was found that the various annealing time in oxygen atmosphere affect the oxidation state of Ti, dye adsorption, and the cell efficiency. For different annealing time, higher cell efficiency was obtained when with O2 was used as the annealing 90 minute.
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TU, WUN WUN, and 杜玟玟. "The Electrochemical Study of Polyaniline as the Counter Electrode for Dye Sensitized Solar Cells." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/44218323445844149005.
Full textAbstract:
碩士輔仁大學
化學系
97
In this study, the electro-deposited polyaniline (PANI) films are used as a counter electrode for dye-sensitized solar cell (DSSC), because of their unique properties, such as low-cost, high-conductivity, good stability, and catalytic activity for I3- reduction. The fabricative processes of PANI counter electrodes are: first, the electro-polymerization of aniline on the large-area TCO (FTO, ITO, PET/ITO) substrate to form the thickness (130 μm) and uniform PANI film; second, to thin the PANI film about 700 nm by sonication method; third, to exchange the HSO4- counter ion to I- counter ion in the PANI film. Cyclic volta- mmograms of I3-/I- measurement reveals that the polyaniline dope I- ion modify TCO electrode has higher electrocatalytic activity for the I3-/I- redox reaction than that Pt electrode does. The energy conversion efficiency of the DSSC with the FTO/PANI(I-), ITO/PANI(I-) and PET/ITO/PANI(I-) counter electrodes are 4.06%, 2.12% and 2.21%, respectively. From the impedance analysis of DSSC, it was found that (1) the intrinsic resistance of TCO substrate, (2) the resistance of interface between the PANI and TCO substrate, (3) the charge-transfer resistance of PANI film to the I3-/I- electrolyte will influence the FF value of photoelectric conversion performances of the DSSC.
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Shih, Yu-En, and 施友恩. "Study of Metal Nanoparticles/Graphene Nanohybrids as Counter Electrode for Dye-sensitized Solar Cells." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/spgq5s.
Full textAbstract:
碩士國立臺灣科技大學
材料科學與工程系
106
In this study, we investigated the dispersibility of graphene-based material by a simple solution dispersion processing with the polyamide surfactant; utilization of nanocomposites in the counter electrode of DSSC was discussed in the same time. In the beginning, surfactant was synthesized and analysis by FT-IR, GPC, solubility. By efficiently assisting reduced graphene oxide(rGO), polyamide surfactant was used in the further experiment. Secondly, to elaborate mechanism of dispersion, different rGO were analyzed by Raman spectrum, FT-IR and element analysis. Thirdly, dye-sensitized solar cell with different oxygen-containing rGO-based counter electrode were studied. TiO2, N719, and I-/I3- were used to compose the DSSCs. The DSSC with the GO20(20% oxygen-containing) counter electrode exhibited a power conversion efficiency(η) of 5.8 %, which was comparable with DSSC with Pt electrode (7 %) under AM 1.5 illumination of 100mW cm-2. With sputter 10 nm platinum on GO20 counter electrode, the efficiency achieved 6.8 % which superior to 10 nm Pt counter electrode (3.4%). The result indicated rGO-based counter electrode need sufficient active site to catalyze tri-iodide. Finally, DSSC of FTO-free rGO/gold nanoparticles(AuNPs) were studied, replacing FTO and platinum by rGO/AuNPs film. The film with rGO/AuNPs exhibited low sheet resistance 10.3 Ω/sq, which is lower than FTO 12 Ω/sq sheet resistance. The different weight ratio of rGO/AuNPs were measured at 200/1, 20/1, 2/1. FTO-free DSSC with rGO/AuNPs 20/1 display highest efficiency at 3.66%, surpass the efficiency of FTO-free Pt electrode with 3.11% efficiency. The result provided an achievable way to enhance efficiency and cost-reduction of DSSCs.
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Perdue, Robbyn K. "Electrokinetic focusing of charged species at bipolar electrode in a microfluidic device." Thesis, 2010. http://hdl.handle.net/2152/ETD-UT-2010-12-2162.
Full textAbstract:
The development and characterization of bipolar electrode (BPE) focusing is described. BPE focusing is an electrokinetic equilibrium technique in which charged analytes are focused and locally enriched on an electric field gradient in the presence of a counter-flow. This electric field gradient is formed at the boundary of an ion depletion zone – the direct result of faradaic reactions occurring at the BPE in the presence of an externally applied electric field.
Direct measurement of the electric field strength in the ion depletion region shows that the electric field is enhanced in this region and takes on a gradient shape, confirming the results of numerical simulations. Transient electric field measurements with simultaneous monitoring of a focused fluorescent tracer reveal that the field gradient forms rapidly upon application of the external field and remains stable over time with the tracer focused at a local field strength predicted by simple electrokinetic equations.
These transient electric field measurements probe the effect of individual experimental parameters on the electric field gradient and the focused band. The results of these studies indicate that a steeper field gradient leads to enhanced concentration enrichment of the analyte. The slope of the gradient is increased with higher concentration of the running buffer and higher applied field strength. The addition of pressure driven flow across the microchannel moves the location of the field gradient and the position of the focused band. Further enhancement of enrichment is achieved through the suppression of Taylor dispersion after coating the microchannel with a non-ionic surfactant.
The findings of these studies have motivated the transition of BPE focusing to smaller microchannels. A decrease in microchannel size not only decreases Taylor dispersion, but also provides access to higher buffer concentration and higher applied field strength, both of which enhance enrichment. The result is a three-order-of-magnitude increase in total analyte enrichment at a much higher enrichment rate. Furthermore, a dual channel configuration for BPE focusing is introduced which provides greater control over focusing conditions.
Finally, the formation of ion depletion and enrichment zones at a BPE in a microchannel is shown to mimic ion concentration polarization (ICP) at micro-/nano-channel junctions. This is significant because this faradaic ICP provides a model to which traditional ICP can be compared and is achieved in a more easily fabricated device.
In summary, the fundamental principles of BPE focusing are described. A greater understanding of the effect of experimental parameters on the focusing process leads to an unprecedented magnitude and rate of enrichment in a simple device architecture.text
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Chien-HengChen and 陳建亨. "Fabrication of Efficient Platinum Counter Electrodes with High Transparency for Dye-Sensitized Solar Cell Applications." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/46404371685583204966.
Full textAbstract:
碩士國立成功大學
化學工程學系碩博士班
98
Platinum films were deposited on indium tin oxide (ITO) substrates in a sputtering process and electrodeposition process used as counter electrodes of dye-sensitized solar cells. The purpose in preparing is mainly provided with high transmittance and high catalytic activity of platinum counter electrode. By sputtering process and Pt film (1.4nm), Pt film has the best catalytic activity and the highest transmittance (76%, wavelength 550nm), and the efficiencies of front-side and back-side illumination are 7.3% and 5.9, respectively. By Electrodeposition with direct current (0.1A and 0.3s), Pt film has high transmittance (81%, wavelength 550nm). For the back-side illumination, the efficiency is closed to one by sputtering process. With pulse current (0.1A, 0.1s on-time，0.3s off-time，18 cycles) , the Pt film has higher catalytic activity. For the front-side illumination, the efficiency is closed to the one by sputtering process. Preparing Pt film by sputtering process and electrodeposition process, the ratio of the energy conversion efficiencies between back (ηb) and front (ηf) illumination, (ηb/ηf), are 0.80 and 0.82 respectively. These values are higher in comparison with those reported in the literature. This result shows the sputtering process and electrodeposition process will increase the efficiency of back-side illumination.
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Chua, Yi Ting, and 蔡伊婷. "Comparison of electrodeposited platinum counter electrodes for quasi-solid state flexible dye-sensitized solar cells." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/78820303945525217919.
Full text
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Zhang, Huan Qing, and 張煥青. "The Fabrication and Electrochemical Analyses of Pt Counter Electrodes in Dye Sensitized Solar Cells (DSSCs)." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/96894471711746526841.
Full textAbstract:
碩士明志科技大學
化工與材料工程研究所
98
In this study, the Pt counter electrodes used as soft substrate (polyethylene terephthalate, PET) and glass substrates as the substrates were prepared and applied on dye-sensitized solar cells (DSSCs). The Pt counter electrodes were prepared by the pulsed plating and sputtering methods for dye-sensitized solar cells. The advantages of the Pt counter electrodes prepared by pulsed plating method have high activity, high specific surface area, fast preparation and easily mass production. The negative electrode was prepared by using the FTO/glass or the ITO/PET coated with P25 TiO2. Those TiO2 electrodes were assembled with Pt counter electrodes to form dye-sensitized solar cells. The surface morphology of as-prepared Pt electrodes was studied by using SEM/EDX; the chemical composition of the electrodes was measured by ICP-OES; the surface resistivity of the electrodes was measured by FPP; the surface morphology and roughness of the electrodes were measured by AFM; the charge transfer resistance of the electrodes was investigated by AC impedance; the electrochemical activity of the electrodes for I-/I3- electrolyte pair was studied by CV method. Finally, the electrical properties and optical conversion efficiency of the DSSCs were measured, respectively. It was found that the electrochemical activities of the pulsed plating Pt electrodes are much better than those of the direct current plated and the sputtered Pt counter electrodes. It was found that the optimal condition for preparation pulsed plating Pt electrodes on the DSSC is at D=0.2, ton = 0.1s, toff = 0.4s. The conversion efficiency of the DSSCs based on FTO/glass is 5.99%; However, the conversion efficiency of the flexible DSSCs based on ITO/PET is 1.96%.
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Lien, Chih-Heng, and 連志恒. "Multi-Wall Carbon Nanotubes Based Counter Electrodes for Dye-Sensitized Solar Cells by Electrophoretic Deposition." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/15985793805300269321.
Full textAbstract:
碩士國立清華大學
化學工程學系
99
In recent years, dye-sensitized solar cells (DSSCs) have aroused intensive interests due to their high efficiency, low cost, and simple fabrication procedure. Pt is still the effective catalytic material for a DSSC counter electrode to reduce voltage loss and speed up the reduction of triiodide (I3-) ions. In order to reduce the cost of DSSCs, great deals of alternatives have been proposed to replace noble Pt. Multi-wall carbon nanotube (MWCNT) is one of the promising alternatives due to its high specific surface area and rapid electron transfer nature. Until now, various approaches have been made to fabricate MWCNT-base counter electrode, such as screen printing, doctor-blade and chemical vapor deposition. Most of methods must need the requirement of high temperature treatment to remove binder from the paste after the coating. The use of heat treatment limits the application in plastic substrates, and thus a low temperature method to fabricate the MWCNT-base film is needed for flexible DSSCs. In this study, electrophoretic deposition (EPD) was employed to make MWCNT-base counter electrode for DSSC. Firstly, an acid mixture solution was used to functionalize MWCNTs. According to the Raman spectra and SEM results, the defects and open-ends were observed by chemical functionalization. In general, those defects and open-ends would become catalytic sites and benefit the enhancement in the catalytic ability of MWCNTs. Consequently, it can be observed that the catalytic ability of MWCNT-base electrode and the efficiency of DSSC assembled with MWCNT-base counter electrode were much improved by the optimization of surface functionalization on the MWCNT. In addition, the CV test demonstrated that an excellent electrochemical stability of the prepared MWCNT counter electrode can be obtained. Comparing with tape-cast, the CNT electrode fabricated by EPD had better adhesion and catalytic ability because the binder added into the paste for coating CNT film by doctor blade which may produce some shielding effect on CNT and lower its catalytic ability. Therefore, the MWCNT electrode prepared by EPD could be great potential for use in low-cost DSSCs.