Photoelectrical conversion

In addition, SWNTs have been expected to act as acceptors or molecular wires in molecular photoelectric conversion since they have attractive electron-accepting... 

Fig.4.30 Immobilization ofthe bacterial photosynthetic reaction center on tailored three-dimensional wormlike mesoporous W03-Ti02 films for artificial photosynthetic systems (A) procedure of film coating (B) proposed scheme of photoelectric conversion. Reprinted with permission from [229], Y. Lu et at., Langmuir 2005, 21, 4071. 2005, American Chemical Society.

Applications in the area of solar cells are semiconductors containing dyes with a 5-5 bicyclic ring system such as 93 (Figure 8) which show high photoelectrical conversion efficiency <2005JAP(K)2005209682>. 

Shen, J. Zhu, Y. Yang, X. Zong, ]. Zhang, J. Li, C., One-pot Hydrothermal Synthesis of Graphene Quantum Dots Surface-passivated by Polyethylene Glycol and Their Photoelectric Conversion under Near-infrared Light. New). Chem. 2012,36 97-101. 

The colour filter layer consists of the RGB colour elements set inside the so-called black matrix, which prevents leakage of light from the different pixels and also stops any photoelectrical conversion in the TFT. The structure of the colour filter layer, illustrated in Figure 5.7, is constructed on a clear substrate, and consists of the RGB hlter units, the black matrix interlayer, an overcoat layer, and an ITO him. Amongst the preferred methods for constraction of pigment based colour hlter layers are photolithographic printing and electrodeposition processes. ... 

Additional tt-conjugated polymers, (I), were prepared by the authors (1) and used as photoelectric conversion elements. 

Gregg et at.si) examined photosensitization of perylene pigments (Dye 15-17) on a porous Sn02 thin film instead of Ti02 film as DSC, in view of energy matching with conduction band of semiconductors and LUMO of the sensitizers. When perylene-3,4-dicarboxylic acid-9,10-(5-phenanthroline) carboximide (Dye 15) was used, Jsc of 3.26 mA-cm 2, of 0.45 V, and a photoelectric conversion efficiency of 0.89% were observed under AM 1.5 irradiation. IPCE achieves close to 40% at 460 nm. 

III. PHOTOELECTRIC CONVERSION SYSTEM USING PORPHYRIN AND REDOX-CONDUCTING METAL COMPLEX WIRES 401... 

In this chapter, we describe three different systems with which to construct electro- and photo-functional molecular assemblies on electrode surfaces. The first is the bottom-up fabrication of redox-conducting metal complex oligomers on an electrode surface and their characteristic redox conduction behavior, distinct from conventional redox polymers.11-13 The second is a photoelectric conversion system using a porphyrin and redoxconducting metal complex.14 The third is the use of a cyanobacterial photosystem I with molecular wires for a biophotosensor and photoelectrode.15 16 These systems will be the precursors of new types of molecular devices working in electrolyte solution. 

Photoelectric Conversion System Using Porphyrin and Wires 401... 

While molecular assembly has proven to be effective for a photoelectric conversion system, coordination reactions are possibly a simple approach for connecting such functional molecules, as presented in the previous section. We applied the stepwise coordination method to prepare a photoelectric conversion system. Since the molecular wire exhibits redox conduction through the wire,11,13 efficient photo-electron transport through the redox sites in the wire is also expected. In this section, we demonstrate the fabrication of a photoelectric conversion system using ITO electrodes modified with M(tpy)2 (M = Co, Fe, Zn) complex wires with a terminal porphyrin moiety as a photosensitizer. The behavior of photo-electron transfer from porphyrin to ITO through the molecular wire was investigated by changing the metal element in the M(tpy)2 moieties.14... 

Photosynthesis, another potential target of bioconjugation, is one of the most important processes in nature. In photosynthesis, photoelectric conversion with nearly 100% efficiency is involved in the primary process.47-48 Such a high performance of photosystem I (PSI) is due to its well-designed spatial configuration. A large number of trials have applied such biological systems to electronic devices. For example, chloroplasts coated on an SnC>2 electrode have been examined as photoelectrochemical cells.49-53... 

In this chapter, we presented three different systems of molecular assemblies using molecular wires. The first involved the fabrication of the molecular wire system with metal complex oligomer or polymer wires composed of bis(terpyridine)metal complexes using the bottom-up method. This system showed characteristic electron transfer distinct from conventional redox polymers. The second involved the fabrication of a photoelectric conversion system using ITO electrodes modified with porphyrin-terminated bis(terpyr-idine)metal complex wires by the stepwise coordination method, which demonstrated that the electronic nature of the molecular wire is critical to the photoelectron transfer from the porphyrin to ITO. This system proposed a new, facile fabrication method of molecular assemblies effective for photoelectron transfer. The third involved the fabrication of a bioconjugated photonic system composed of molecular wires and photosystem I. The feasibility of the biophotosensor and the biophotoelectrode has been demonstrated. This system proposed that the bioconjugation and the surface bottom-up fabrication of molecular wires are useful approaches in the development of biomo-lecular devices. These three systems of molecular assemblies will provide unprecedented functional molecular devices with desired structures and electron transfer control. 

A photoelectric conversion device 10 is formed in a p-type HgCdTe substrate 11 and a CCD 20 is formed in a p-type silicon substrate 13. Indium electrodes 4a and 4b, which are connected to the photoelectric conversion device and the CCD, respectively, are covered on their sides with shape-memory metal layers 5a and 5b. Pressure bonding is used to couple the photoelectric conversion device to the CCD. Thereafter, the temperature is raised to return the shape-memory metal to its original shape, at the same time releasing mechanical stress in the indium electrodes. 

Liu prepared a sandwich type coordination compound (103) from porphyrin and phthalocyanine with the assistance of a microwave. The resulted compounds showed good solubility in conventional organic solvents. The photoelectric conversion properties have been tested with a Gratzel type cell. The results revealed that the sandwich type compound showed better photo-electric conversion efficiency than the corresponding monomeric porphyrin or phthalocyanine precursors. The short-circuit photocurrent of the solar cell with this sandwich type compound as sensitizer, was, as high as 691.31 A cm-2, which was much better, than those of porphyrin or phthalocyanine monomers [100]. 

Miscelleanous related works on the optical properties of dithiolene complexes have been published, and will be cited here just for recollection photoconductivity (525, 526) photoelectrical conversion and photoswitching (420, 527-529) and photosensitive materials (530). 

As previously mentioned in Section IV, some dithiolene complexes might exhibit under light irradiation induced properties such as photocurrent generation or photoelectric conversion (420, 527-529). Such behaviors are discussed in details in Chapter 6 of this volume (352). 

A fullerene-based amine-carboxylate ligand (204), able to form monolayer films with particular photoelectric conversion properties, has also been synthesized.302... 

Doping a nano-structured Ti02 electrode sensitized with tetrasulfonated gallium phthalocyanine with tetrasulfonated zinc porphyrin (ZnTsPP) greatly enhances the photoelectric conversion at long wavelengths, with 20- and 60-fold improvement of the quantum efficiency at 680 and 700 nm [195],... 

Photoelectric Conversion by Polymeric and Organic Materials M Kaneko... 

Iti the array of 768 individual detectors, each element is about one millimeter wide. The spacing between the elements is rather small, but is present to suppress cross talk by interstitials. Such a detector is shown in principle in Fig. 8.8. The X rays absorbed by the phosphor material are converted into visible light, which is detected by the coupled photodiode. The electrical signal is generated by photoelectric conversion. 

Tsuzuki, T., Shirota, Y, Rostalski, J., and Meissner, D. 2000. The effect of fullerene doping on photoelectric conversion using titanyl phthalocyanine and a perylene pigment. Solar Energy Materials and Solar Cells 61 (l) l-8. 

Similar to photoelectrochemical solar cells, the concept of solid-state sensitized heterojunctions has the great advantage over conventional inorganic solar cells that only majority carriers are involved in the photoelectric conversion process. Photoelectric conversion in conventional inorganic p-n junction solar cells involves minority carriers whose lifetime is restricted... 

A = electrochromism B = photoelectric conversion C = electrogenerated chemiluminescence D = highly dispersed noble metal E = catalyst F = high mechanical strength conducting polymer, G = charge-controllable transport membrane H = sensor. 

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