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 ...

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Dye-Sensitized Solar Cells

The use of conductivity measurements in organic solvents for the characterisation of coordination compounds

J. Appl. Cryst.の発刊に際して

A fundamental aim in the field of catalysis is the development of new modes of small molecule activation. One approach toward the catalytic activation of organic molecules that has received much attention recently is visible light photoredox catalysis. In a general sense, this approach relies on the ability of metal complexes and organic dyes to engage in single-electron-transfer (SET) processes with organic substrates upon photoexcitation with visible light.

Many of the most commonly employed visible light photocatalysts are polypyridyl complexes of ruthenium and iridium, and are typified by the complex tris(2,2′-bipyridine) ruthenium(II), or Ru(bpy)32+ (Figure 1). These complexes absorb light in the visible region of the electromagnetic spectrum to give stable, long-lived photoexcited states.1,2 The lifetime of the excited species is sufficiently long (1100 ns for Ru(bpy)32+) that it may engage in bimolecular electron-transfer reactions in competition with deactivation pathways.3 Although these species are poor single-electron oxidants and reductants in the ground state, excitation of an electron affords excited states that are very potent single-electron-transfer reagents. Importantly, the conversion of these bench stable, benign catalysts to redox-active species upon irradiation with simple household lightbulbs represents a remarkably chemoselective trigger to induce unique and valuable catalytic processes.






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Figure 1


Ruthenium polypyridyl complexes: versatile visible light photocatalysts.

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Visible Light Photoredox Catalysis with Transition Metal Complexes: Applications in Organic Synthesis

Excitonic solar cells1—including organic, hybrid organic–inorganic and dye-sensitized cells (DSCs)—are promising devices for inexpensive, large-scale solar energy conversion. The DSC is currently the most efficient2 and stable3 excitonic photocell. Central to this device is a thick nanoparticle film that provides a large surface area for the adsorption of light-harvesting molecules. However, nanoparticle DSCs rely on trap-limited diffusion for electron transport, a slow mechanism that can limit device efficiency, especially at longer wavelengths. Here we introduce a version of the dye-sensitized cell in which the traditional nanoparticle film is replaced by a dense array of oriented, crystalline ZnO nanowires. The nanowire anode is synthesized by mild aqueous chemistry and features a surface area up to one-fifth as large as a nanoparticle cell. The direct electrical pathways provided by the nanowires ensure the rapid collection of carriers generated throughout the device, and a full Sun efficiency of 1.5% is demonstrated, limited primarily by the surface area of the nanowire array.

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Nanowire dye-sensitized solar cells

Inorganic Electronic Spectroscopy

Inorganic electronic spectroscopy

This book brings together the most recent research on the fundamental and applied chemistry of the phthalocyanine derivatives. More particularly, their redox character, essential to many of their potential industrial applications, are presented in this book in a detailed and comprehensive way. Together, the three volumes cover a broad spectrum of the physical and chemical aspects of the phtalocyanines and some of their relatives, providing a firm, up-to-date basis for future exploration of these very important species. The unique properties of phthalocyanines have generated worldwide interest in their use in chemical sensors, electronic display devices, photoconduction, fuel cells, molecular metals, electrocatalysis, molecular computers, pollution control devices, liquid crystals, photodynamic therapy and biological stains.

Phthalocyanines : properties and applications

Electronic structure and spectra of ruthenium diimine complexes by density functional theory and INDO/S. Comparison of the two methods

: A ligand electrochemical parameter, El (L), is described to generate a series which may be used to predict M(n)/M(n-1( redox potentials by assuming that all ligand contributions are additive. In this fashion it performs a similar purpose to the Dq parameter in electronic spectroscopy. The parameter is defined as 1/6 that of the Ru(III)/Ru(II) potential for species RuL6 in acetontrile. The El(L) values for over 200 ligands are presented and the model is tested over a wide range of coordination complexes and organometallic species. The redox potential of a M(n)/M(n-1) couple is defined to be equal to:- E(calc) = f Sigma EL (L) + c. The values of f and C, which are tabulated, depend upon the metal and redox couple, and upon spin state and stereochemistry, but, in organic solvents, are generally insensitive to the net charge of the species. Consideration is given to synergism, the potentials of isomeric species, and the situations where the ligand additivity model is expected to fail. In this initial study, the redox couples are restricted almost exclusively to those involving the loss or addition of an electron to the tzg (in Oh) sub-level.

Electrochemical parametrization of metal complex redox potentials, using the ruthenium(III)/ruthenium(II) couple to generate a ligand electrochemical series

A. B. P. Lever

Papers

Inorganic Electronic Spectroscopy

Inorganic electronic spectroscopy

Phthalocyanines : properties and applications

Electronic structure and spectra of ruthenium diimine complexes by density functional theory and INDO/S. Comparison of the two methods

Electrochemical parametrization of metal complex redox potentials, using the ruthenium(III)/ruthenium(II) couple to generate a ligand electrochemical series