Titanium Dioxide Nanomaterials: Synthesis, Properties, Modifications, and Applications

Dye-sensitized solar cells (DSCs) offer the possibilities to design solar cells with a large flexibility in shape, color, and transparency. DSC research groups have been established around the worl ...

/pdf/dye-sensitized-solar-cells-50b0w2bhsr.pdf

Dye-Sensitized Solar Cells

Transparent, conductive, and ultrathin graphene films, as an alternative to the ubiquitously employed metal oxides window electrodes for solid-state dye-sensitized solar cells, are demonstrated. These graphene films are fabricated from exfoliated graphite oxide, followed by thermal reduction. The obtained films exhibit a high conductivity of 550 S/cm and a transparency of more than 70% over 1000−3000 nm. Furthermore, they show high chemical and thermal stabilities as well as an ultrasmooth surface with tunable wettability.

Transparent, Conductive Graphene Electrodes for Dye-Sensitized Solar Cells

We report a combined experimental and computational study of several ruthenium(II) sensitizers originated from the [Ru(dcbpyH2)2(NCS)2], N3, and [Ru(dcbpyH2)(tdbpy)(NCS)2], N621, (dcbpyH2 = 4,4‘-dicarboxy-2,2‘-bipyridine, tdbpy = 4,4‘-tridecyl-2,2‘-bipyridine) complexes. A purification procedure was developed to obtain pure N-bonded isomers of both types of sensitizers. The photovoltaic data of the purified N3 and N621 sensitizers adsorbed on TiO2 films in their monoprotonated and diprotonated state, exhibited remarkable power conversion efficiency at 1 sun, 11.18 and 9.57%, respectively. An extensive Density Functional Theory (DFT)−Time Dependent DFT study of these sensitizers in solution was performed, investigating the effect of protonation of the terminal carboxylic groups and of the counterions on the electronic structure and optical properties of the dyes. The calculated absorption spectra are in good agreement with the experiment, thus allowing a detailed assignment of the UV−vis spectral features ...

Combined Experimental and DFT-TDDFT Computational Study of Photoelectrochemical Cell Ruthenium Sensitizers

Dye-sensitized solar cells (DSSC) have attracted considerable attention in recent years as they offer the possibility of low-cost conversion of photovoltaic energy This Review focuses on recent advances in molecular design and technological aspects of metal-free organic dyes for applications in dye-sensitized solar cells Special attention has been paid to the design principles of these dyes and on the effect of various electrolyte systems Cosensitization, an emerging technique to extend the absorption range, is also discussed as a way to improve the performance of the device In addition, we report on inverted dyes for photocathodes, which constitutes a relatively new approach for the production of tandem cells Special consideration has been paid to the correlation between the molecular structure and physical properties to their performance in DSSCs

Metal-Free Organic Dyes for Dye-Sensitized Solar Cells: From Structure: Property Relationships to Design Rules

Nanoporous electrode films are prepared from different sized anatase TiO2 nanoparticles, of which the average diameter is 14, 19, and 32 nm. Dye-sensitized solar cells are prepared from the films. Diffusion coefficients of electrons (D) in the solar cells are estimated by photocurrent transient measurements using a small-intensity laser pulse under continuous irradiation of bias light. Electron recombination lifetimes (τ) in the solar cells are measured by intensity-modulated photovoltage measurement (IMVS). It is found that the D increases and τ decreases with the increase of the particle size up to 32 nm. The increase of the D is interpreted with the decrease of the film surface area, where the charge trap sites are likely to exist, and the condition of grain boundary. The decrease of τ is discussed with the change of surface area and D with the particle size.

Influence of TiO2 Nanoparticle Size on Electron Diffusion and Recombination in Dye-Sensitized TiO2 Solar Cells

I−/I3− redox reaction behaviors on chemically polymerized p-toluenesulfonate doped poly(3,4-ethylenedioxythiophene) (PEDOT-TsO) and sputtered-Pt electrode were characterized to compare its performance as the counter electrode in dye sensitized solar cells (DSCs). Adsorption of iodide species at the PEDOT surface, as well as Pt surface was little affected the redox reaction at the low concentration of redox couple. The PEDOT-TsO film had porous structure and charge transfer resistance of the PEDOT-TsO electrode decreased with the thickness. Photovoltaic performance of DSCs with PEDOT-TsO counter electrode (CE) also improved with the thickness of PEDOT-TsO when ionic liquid was used for the electrolyte. The use of porous PEDOT-TsO counter electrode that has low cost, simplified fabrication process and sufficient catalytic activity could enhance the potential of the DSCs for practical use.

I−/I3− redox reaction behavior on poly(3,4-ethylenedioxythiophene) counter electrode in dye-sensitized solar cells

Dye-sensitized solar cells fabricated using chemically polymerized poly(3,4-ethylenedioxythiophene) on a conductive glass as a counter electrode showed comparable conversion efficiency with a cell using platinum sputtered counter electrode.

Yasuteru Saito

Papers

Influence of TiO2 Nanoparticle Size on Electron Diffusion and Recombination in Dye-Sensitized TiO2 Solar Cells

I−/I3− redox reaction behavior on poly(3,4-ethylenedioxythiophene) counter electrode in dye-sensitized solar cells

Application of poly(3,4-ethylenedioxythiophene) to counter electrode in dye-sensitized solar cells

Solid state dye sensitized solar cells using in situ polymerized PEDOTs as hole conductor

Morphology control of mesoporous TiO2 nanocrystalline films for performance of dye-sensitized solar cells