Study on Dye Sensitized Solar Cells for Improved Performances

Department of Chemical EngineeringThis thesis is focused on the improvement of performance of DSC. Unique materias as Zno, odered mesoporous carbon, graphene-metal nonoparticle composit was introduced to DSC to deveolp the performance. In this thesis ZnO with novel nanostructure was introdueced with adventage of large surface area and good morphology for penetrating of the dye solution. This work provides intriguing way of structurally designing of ZnO with large surface area and moderate morphology for DSSCs and other applications. rGO/metal nanoparticle hybrid films and OMC–CNT, where the primary particles of the OMCs are interconnected via the CNTs are introduced for counter electrodes in DSC as Pt replacement counter electrode. The enhanced electrochemical stability of the Au nanoparticles on rGO was attributed to the unique combination of the presence of defects as well as hydroxyl and carboxyl functional groups. the OMC–CNT-based cell showed an excellent cell efficiency which was primarily attributed to its remarkably enhanced electrical conductivity as well as its intrinsic catalytic activity. This work provides an intriguing way of structurally designing a low-cost, Pt-free, high-performance counter electrode material for DSC. New coating method for DSC working-electrode is introduced, too. The method controls the reaction temperatures with concentrations of N719 in various solvents. Sorts of alcohols and DMSO was invetigaed and can be ideally applied to shorten the coating time to only 3 min which is much improved from the several hour scale needed for the conventional solvents such as acetonitrile and ethanol. The cells were compared by characterization with JV measurement, dye uptake amount, DRIFT, and EIS. Performance and other characteristics of the cells with working electrodes prepared by this new methods were very comparable to those prepared by conventional methods.ope

Organic-skinned inorganic nanoparticles: surface-confined polymerization of 6-(3-thienyl)hexanoic acid bound to nanocrystalline TiO2

There are many practical difficulties in direct adsorption of polymers onto nanocrystalline inorganic oxide surface such as Al2O3 and TiO2 mainly due to the insolubility of polymers in solvents or polymer agglomeration during adsorption process. As an alternative approach to the direct polymer adsorption, we propose surface-bound polymerization of pre-adsorbed monomers. 6-(3-Thienyl)hexanoic acid (THA) was used as a monomer for poly[3-(5-carboxypentyl)thiophene-2,5-diyl] (PTHA). PTHA-coated nanocrystalline TiO2/FTO glass electrodes were prepared by immersing THA-adsorbed electrodes in FeCl3 oxidant solution. Characterization by ultraviolet/visible/infrared spectroscopy and thermal analysis showed that the monolayer of regiorandom-structured PTHA was successfully formed from intermolecular bonding between neighbored THA surface-bound to TiO2. The anchoring functional groups (-COOH) of the surface-crawling PTHA were completely utilized for strong bonding to the surface of TiO2

Nano-structures Embedded Perovskite Solar Cells

Organic-inorganic hybrid perovskite solar cells (PSCs) are now attracting tremendous attention for new-generation photovoltaic device because of their excellent power conversion efficiency (PCE) and simple fabrication process. Various researches have been carried out to increase the efficiency of PSCs. Herein, we report on the three methods for enhanced performances of PSCs based on nanoimprint lithography technology

Highly interconnected ordered mesoporous carbon-carbon nanotube nanocomposites: Pt-free, highly efficient, and durable counter electrodes for dye-sensitized solar cells

We report the preparation of highly interconnected ordered mesoporous carbon-carbon nanotube nanocomposites which show Pt-like dye-sensitized solar cell (DSSC) efficiency and remarkable long-term durability as DSSC counter electrodes.close413

Electrochemical Approaches to Dye-Sensitized Solar Cells

??? ??????????????? ?????? ?????? ???????????? ?????? ???????????? ??????????????? ?????? ??????????????? ????????? ?????? ????????????. ??????, ?????? ?????? ????????? ???????????? ????????? ??????????????? ?????? ?????? ?????? ????????????, ??????????????? ????????? ??????????????? ????????? ??? ???????????? ????????????. ?????? ???????????? ??????????????? ???????????? ??? ????????? ????????? ??????. ?????????, ?????????????????? ?????? ???????????? ??????????????? ???????????? ????????????, ????????? ????????? ??? ????????? ???????????? ???????????? ?????? ????????????. ?????????????????? ?????? ???????????? ??????????????? ???????????????????????? ??????, ???????????? ??????????????? ????????? ???????????? ?????????????????? ??????, ???????????? ????????? ?????? ???????????? ????????? ????????? ????????????. This paper describes one of the hot issues in solar cell studies, dye-sensitized solar cell. DSSC is a kind of photoelectrochemical cells. Therefore, it is quite different from the conventional solar cells which originate from pn semiconductor theory, although its mechanism can be explained with the theory. This paper describes the difference between the conventional semiconductor approaches and a newly adapted one for DSSC. Especially, electrochemical analysis methods such as electrochemical impedance analysis and cyclic voltammogram are briefly introduced, which are commonly used for DSSC analysis.clos

Densely packed setose ZnO nanorod arrays for dye sensitized solar cells

Dye sensitized solar cells (DSSCs) have been fabricated with setose ZnO nanostructures. Curved plate ZnO nanosheet (CPZ) layer has been built up by air-brush method and conventional ZnO nanosheet has been synthesized with methanolic solution method. ZnO nanorods were grown on both nanosheet structures. The setose ZnO nanostructure was grown on CPZ layer and applied at photoanode for DSSCs. The performance of DSSCs is developed due to the structure of easy penetrating for dye solution and large surface area of the novel nanostructure of ZnO photoelectrode.close1

Flexible organo-metal halide perovskite solar cells on a Ti metal substrate

Organo-metal halide perovskite solar cells have received much attention in the field of photovoltaics in recent years. Herein, we report a flexible perovskite solar cell based on a metal substrate. It showed a power conversion efficiency of over 6% for the first time using a silver thin film as a semi-transparent top electrode on a Ti substrate.close7

Thiophene-fused coplanar sensitizer for dye-sensitized solar cells

We have designed and synthesized a novel ladder-type heteroacene dye consisting uniquely of thiophene segments as a photosensitizer for the dye-sensitized solar cells (DSSCs). The onset of the IPCE spectrum for the dye not only reaches up to 700 nm with a high IPCE (>60%) but also a solar energy-to-electricity conversion efficiency of 2.31% is achieved. Even though the efficiency is slightly lower than those of other dyes reported previously, this work opens up a new strategy to design heteroaromatic fused photosensitizers for DSSCs.close6

Efficient, durable and flexible perovskite photovoltaic devices with Ag-embedded ITO as the top electrode on a metal substrate

Efficient flexible perovskite solar cells based on a Ti substrate have been fabricated using indium tin oxide (ITO) as the top electrode. Furthermore, an ultra-thin Ag layer embedded between spiro-MeOTAD and ITO led to lower sheet resistance and a highly durable electrode compared with bare ITO. Inclusion of the Ag thin film has also provided enhanced electromagnetic fields on the surface of Ag for devices, which caused an increase of short circuit currentclose1

A high temperature stable electrolyte system for dye-sensitized solar cells

The effect of the addition of single and binary additives to a mixed solvent, ethylene carbonate + gamma-butytolactone. on the performance of dye-sensitized TiO(2) solar cells (DSSCs) has been investigated The addition of a single additive. 2-(dimethylamino)-pyridine,to the electrolyte containing an ionic salt, 1.2-dimethyl-3-propylimidazolium iodide, in the mixed solvent results in an enhancement of the cell performance The performance of the cell has been further enhanced by the addition of the second additive.5-chloro-1-ethyl-2-methylimidazole The resulting DSSC has performed better than the one based on the conventional electrolyte in acetonitrile The dependence of the stability of the cells on the temperature e has been evaluated vet the range of 30-120 degrees C for outdoor applications.close131