oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Dye-Sensitized Nanocrystalline ZnO Solar Cells Based on Ruthenium(II) Phendione Complexes  [PDF]
Hashem Shahroosvand,Parisa Abbasi,Mohsen Ameri,Mohammad Reza Riahi Dehkordi
International Journal of Photoenergy , 2011, DOI: 10.1155/2011/634147
Abstract: The metal complexes ( (phen)2(phendione))(PF6)2(1), [ (phen)(bpy)(phendione))(PF6)2 (2), and ( (bpy)2(phendione))(PF6)2 (3) (phen = 1,10-phenanthroline, bpy = 2,2′-bipyridine and phendione = 1,10-phenanthroline-5,6-dione) have been synthesized as photo sensitizers for ZnO semiconductor in solar cells. FT-IR and absorption spectra showed the favorable interfacial binding between the dye-molecules and ZnO surface. The surface analysis and size of adsorbed dye on nanostructure ZnO were further examined with AFM and SEM. The AFM images clearly show both, the outgrowth of the complexes which are adsorbed on ZnO thin film and the depression of ZnO thin film. We have studied photovoltaic properties of dye-sensitized nanocrystalline semiconductor solar cells based on Ru phendione complexes, which gave power conversion efficiency of (η) of 1.54% under the standard AM 1.5 irradiation (100?mW?cm?2) with a short-circuit photocurrent density ( ) of 3.42?mA?cm?2, an open-circuit photovoltage ( ) of 0.622?V, and a fill factor (ff) of 0.72. Monochromatic incident photon to current conversion efficiency was 38% at 485?nm. 1. Introduction Dye-Sensitized Solar Cells (DSSCs) [1, 2] are attracting lot of interest because of their low cost and high efficiency. Many researchers have made efforts to modify the cell from various aspects to improve the DSSC efficiency. It is generally accepted that the dye-sensitized reaction step and electron injection step between the electrodes and the excited adsorbed dye are the key steps to control DSSCs efficiency [3–5]. For the optimization of the DSSCs components, that is, the different oxide semiconductor, the dye sensitizer and the electrolyte, exactitude in reporting the experimental procedures used is indispensable in order to compare the data between the many different laboratories active in this field [6, 7]. Titanium dioxide advantages for sensitized photochemistry and photoelectrochemistry including a low-cost, widely available, nontoxic, and biocompatible material, and as such is even used in health care products as well as domestic applications such as paint pigmentation [8, 9]. But, TiO2 films have a significant limitation that makes it difficult to grow on a substrate with controlled structure. This may prevent further development of DSSCs with TiO2 films. One-dimensionally ordered structures of metal oxides, such as rods or wires, will greatly improve DSSCs efficiency [10, 11]. Therefore, extensive attention has been focused on looking for the suitable substitute for TiO2. Among these candidates, ZnO has been expected to be
High Molar Extinction Coefficient Ru(II)-Mixed Ligand Polypyridyl Complexes for Dye Sensitized Solar Cell Application  [PDF]
Malapaka Chandrasekharam,Ganugula Rajkumar,Chikkam Srinivasa Rao,Thogiti Suresh,Yarasi Soujanya,Paidi Yella Reddy
Advances in OptoElectronics , 2011, DOI: 10.1155/2011/432803
Abstract: Two new ruthenium(II) mixed ligand terpyridine complexes, “Ru(Htcterpy)(NCS)(L1) (N(C4H9)4), mLBD1” and Ru(Htcterpy)(NCS)(L2)(N(C4H9)4), mLBD2 were synthesized and fully characterized by UV-Vis, emission, cyclic voltammogram, and other spectroscopic means, and the structures of the compounds are confirmed by 1H-NMR, ESI-MASS, and FT-IR spectroscopes. The influence of the substitution of L1 and L2 on solar-to-electrical energy conversion efficiency (η) of dye-sensitized solar cells (DSSCs) was evaluated relative to reference black dye. The dyes showed molar extinction coefficients of 17600?M?1?cm?1 for mLBD1 and 21300?M?1?cm?1 for mLBD2 both at λ maximum of 512?nm, while black dye has shown 8660?M?1?cm?1 at λ maximum of 615?nm. The monochromatic incident photon-to-collected electron conversion efficiencies of 60.71% and 75.89% were obtained for mLBD1 and mLBD2 dyes, respectively. The energy conversion efficiencies of mLBD1 and mLBD2 dyes are 3.15% ( ?mA/cm2, ?mV, ) and 3.36% ( ?mA/cm2, ?mV, ), respectively, measured at the AM1.5G conditions, the reference black dye-sensitized solar cell, fabricated and evaluated under identical conditions exhibited η-value of 2.69% ( ?mA/cm2, ?mV, ). 1. Introduction Among various photo voltaic technologies, dye-sensitized solar cells (DSSCs) are known to be less expensive, easy to fabricate and very efficient at varied incident angle of light. Therefore, intense attention has been devoted in the last two decades to the synthesis of new materials as sensitizers, metal oxide semiconductors, counter electrode materials, electrolytes, and so forth, for applications in high-performance and long durable DSSCs [1–6]. Especially sensitizer plays important role in the DSSCs device for obtaining high-efficiency and long-term durability because of the possibility to chemically modify the sensitizer for better anchoring on TiO2, electron injection property and HOMO-LUMO tuning. To achieve this, many researchers around the world have been working either on modification of various reported sensitizers or designing new sensitizers. A variety of ruthenium(II) polypyridyl, terpyridyl and tetrapyridyl complexes, metal-free organic sensitizers, porphyrins, and phthalocyanines have been developed, since Graetzel introduced the first efficient nanocrystalline TiO2 solar cell sensitized with cis-bis(thiocyanato) bis(2,2′-bipyridyl-4,4′-dicarboxylato) ruthenium(II) bis (tetrabutylammonium) (N719) [7–14]. Introduced in 1997, another ruthenium complex, black dye [tri(isothiocyanato)-2,2′,2′′-terpyridyl-4,4′,4′′-tricarboxylate ruthenium(II)]
Theoretical Insight into the Spectral Characteristics of Fe(II)-Based Complexes for Dye-Sensitized Solar Cells—Part I: Polypyridyl Ancillary Ligands  [PDF]
Xiaoqing Lu,Shuxian Wei,Chi-Man Lawrence Wu,Ning Ding,Shaoren Li,Lianming Zhao,Wenyue Guo
International Journal of Photoenergy , 2011, DOI: 10.1155/2011/316952
Abstract: The design of light-absorbent dyes with cheaper, safer, and more sustainable materials is one of the key issues for the future development of dye-sensitized solar cells (DSSCs). We report herein a theoretical investigation on a series of polypyridyl Fe(II)-based complexes of FeL2(SCN)2, [FeL3]2+, [FeL′(SCN)3]-, [FeL′2]2+, and FeL′′(SCN)2 (L = 2,2′-bipyridyl-4,4′-dicarboxylic acid, L′ = 2,2′,2″-terpyridyl-4,4′,4″-tricarboxylic acid, L″ = 4,4?-dimethyl-2,2′?:?6′,2″?:6″,2?-quaterpyridyl-4′,4″-biscarboxylic acid) by density functional theory (DFT) and time-dependent DFT (TD-DFT). Molecular geometries, electronic structures, and optical absorption spectra are predicted in both the gas phase and methyl cyanide (MeCN) solution. Our results show that polypyridyl Fe(II)-based complexes display multitransition characters of Fe?→?polypyridine metal-to-ligand charge transfer and ligand-to-ligand charge transfer in the range of 350–800?nm. Structural optimizations by choosing different polypyridyl ancillary ligands lead to alterations of the molecular orbital energies, oscillator strength, and spectral response range. Compared with Ru(II) sensitizers, Fe(II)-based complexes show similar characteristics and improving trend of optical absorption spectra along with the introduction of different polypyridyl ancillary ligands. 1. Introduction Due to the features of low cost and high conversion efficiency, dye-sensitized solar cells (DSSCs) based on organic/inorganic hybrid materials have ?attracted extensive attention as an alternative to the conventional Si-based solar cells [1–3]. As crucial light-harvesting elements in DSSCs, the photoexcited sensitizers can inject electrons from their excited states into the semiconductor conduction band, and are recharged by an electrolyte to their initial states [4–6]. Early design of sensitizers had focused on transition metal coordinated complexes because of their unique richness of electronic properties for light absorption as well as photochemical and photophysical behaviors, especially for the photoredox activities [7]. These behaviors were originated from the nature of the coordinated complexes, involving the metal-to-ligand charge transfer (MLCT) character and intervening spin-orbit coupling attached to the presence of metal cations with large atomic numbers [7]. Metal coordinated complexes also facilitate the fine tuning of electronic properties by means of the proper choice of both polypyridyl ancillary ligands and metal cations. Up to now, polypyridyl Ru(II)-based complexes are proven to be the most efficient sensitizers
Dye Sensitized Solar Cell, DSSC
Pongsatorn Amornpitoksuk,Nareelak Leesakul
Songklanakarin Journal of Science and Technology , 2003,
Abstract: A dye sensitized solar cell is a new type of solar cell. The operating system of this solar cell type is similar to plant’s photosynthesis process. The sensitizer is available for absorption light and transfer electrons to nanocrystalline metal oxide semiconductor. The ruthenium(II) complexes with polypyridyl ligands are usually used as the sensitizers in solar cell. At the present time, the complex of [Ru(2,2',2'’-(COOH)3- terpy)(NCS)3] is the most efficient sensitizer. The total photon to current conversion efficiency was approximately 10% at AM = 1.5.
Efficiency Enhancement of Dye-Sensitized Solar Cells: Using Salt CuI as an Additive in an Ionic Liquid
Efficiency Enhancement of Dye-Sensitized Solar Cells: Using Salt CuI as an Additive in an Ionic Liquid

CHEN Lie-Hang,XUE Bo-Fei,LIU Xi-Zhe,LI Ke-Xin,LUO Yan-Hong,MENG Qing-Bo,WANG Rui-Lin,CHEN Li-Quan,
陈烈杭
,薛勃飞,刘喜哲,李可心,罗艳红,孟庆波,王瑞林,陈立泉

中国物理快报 , 2007,
Abstract: Energy conversion efficiency of the dye-sensitized solar cell is improved from 3.5% to 4.5% by adding a small amount of CuI into an ionic liquid electrolyte. It is found that other copper-I salts, for example, CuBr, have the same effect for the dye-sensitized solar cell. Experimental results show that no Cu 2+ ions exist in this electrolyte. It is suggested that this improvement is caused by the adsorption of Cu+ onto the TiO2 porous film.
Dye-sensitized solar cells: a successful combination of materials
Longo, Claudia;De Paoli, Marco-A.;
Journal of the Brazilian Chemical Society , 2003, DOI: 10.1590/S0103-50532003000600005
Abstract: dye-sensitized tio2 solar cells, dssc, are a promising alternative for the development of a new generation of photovoltaic devices. dssc are a successful combination of materials, consisting of a transparent electrode coated with a dye-sensitized mesoporous film of nanocrystalline particles of tio2, an electrolyte containing a suitable redox-couple and a pt coated counter-electrode. in general, ru bipyridyl complexes are used as the dye sensitizers. the light-to-energy conversion performance of the cell depends on the relative energy levels of the semiconductor and dye and on the kinetics of the electron-transfer processes at the sensitized semiconductor | electrolyte interface. the rate of these processes depends on the properties of its components. this contribution presents a discussion on the influence of each of the materials which constitute the dssc of the overall process for energy conversion. an overview of the results obtained for solid-state dye-sensitized tio2 solar cells assembled with polymer electrolytes is also presented.
Dye-sensitized solar cells: a successful combination of materials  [cached]
Longo Claudia,De Paoli Marco-A.
Journal of the Brazilian Chemical Society , 2003,
Abstract: Dye-sensitized TiO2 solar cells, DSSC, are a promising alternative for the development of a new generation of photovoltaic devices. DSSC are a successful combination of materials, consisting of a transparent electrode coated with a dye-sensitized mesoporous film of nanocrystalline particles of TiO2, an electrolyte containing a suitable redox-couple and a Pt coated counter-electrode. In general, Ru bipyridyl complexes are used as the dye sensitizers. The light-to-energy conversion performance of the cell depends on the relative energy levels of the semiconductor and dye and on the kinetics of the electron-transfer processes at the sensitized semiconductor | electrolyte interface. The rate of these processes depends on the properties of its components. This contribution presents a discussion on the influence of each of the materials which constitute the DSSC of the overall process for energy conversion. An overview of the results obtained for solid-state dye-sensitized TiO2 solar cells assembled with polymer electrolytes is also presented.
Dye Sensitized Solar Cells  [PDF]
Di Wei
International Journal of Molecular Sciences , 2010, DOI: 10.3390/ijms11031103
Abstract: Dye sensitized solar cell (DSSC) is the only solar cell that can offer both the flexibility and transparency. Its efficiency is comparable to amorphous silicon solar cells but with a much lower cost. This review not only covers the fundamentals of DSSC but also the related cutting-edge research and its development for industrial applications. Most recent research topics on DSSC, for example, applications of nanostructured TiO 2, ZnO electrodes, ionic liquid electrolytes, carbon nanotubes, graphene and solid state DSSC have all been included and discussed.
Nanosize Copper Dispersed Ionic Liquids As an Electrolyte of New Dye-Sensitized Solar Cells  [PDF]
Fu-Lin Chen,I.-Wen Sun,H. Paul Wang,C.-H. Huang
Journal of Nanomaterials , 2009, DOI: 10.1155/2009/472950
Abstract: To enhance the electrical conductivity of the electrolyte for a newly developed dye-sensitized solar cell (DSSC), metallic copper (Cu) encapsulated within the carbon shell (Cu@C) nanoparticles dispersed in a room temperature ionic liquid (RTIL) (e.g., [bmim
Ruthenium Sensitizers and Their Applications in Dye-Sensitized Solar Cells
Yuancheng Qin,Qiang Peng
International Journal of Photoenergy , 2012, DOI: 10.1155/2012/291579
Abstract: Dye-sensitized solar cells (DSSCs) have attracted considerable attention in recent years due to the possibility of low-cost conversion of photovoltaic energy. The DSSCs-based ruthenium complexes as sensitizers show high efficiency and excellent stability, implying potential practical applications. This review focuses on recent advances in design and preparation of efficient ruthenium sensitizers and their applications in DSSCs, including thiocyanate ruthenium sensitizers and thiocyanate-free ruthenium sensitizers.
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.