Energy conversion: from the ligand field photochemistry to solar cells

Garcia, Christian Graziani; Lima, Jailson Farias de; Iha, Neyde Yukie Murakami

doi:10.1016/s0010-8545(98)00212-4

Cited by 75 publications

(63 citation statements)

References 187 publications

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“…As linhas de pesquisa são as mais variadas e têm alcançado índices de impacto muito expressivos. Dentre os artigos mais citados no levantamento realizado no ISI, foram encontrados principalmente estudos nas áreas de nanomateriais magnéticos 28,29 , química e nanomateriais supramoleculares [30][31][32][33][34][35][36][37] , nanocompósitos de polímeros e óxi-dos de metais de transição (principalmente nanopartículas e óxidos lamelares) [38][39][40][41][42] , nanoencapsulamento 43 , nanotubos de carbono 44,45 ; filmes, interfaces e dispositivos 34,35,37,46,47 e células solares [48][49][50] . Essas contribuições são brevemente comentadas abaixo.…”

Section: Principais Linhas E Contribuiçõesunclassified

“…O estudo do processo de injeção de elétrons mostrou que cerca de 1/3 das espécies no estado excitado realizam diretamente esse processo, mas as demais injetam elétrons somente após uma reação de transferência de elétrons intramolecular envolvendo a formação da espécie Rh(II)-Ru(III). Por outro lado, Garcia e colaboradores 49,50 realizaram estudos voltados para o desenvolvimento de células fotoeletroquímicas utilizando diversas moléculas como sensibilizadores, inclusive pigmentos naturais.…”

Section: Figura 2 A) Gráficos Mostrando O Número De Publicações E B)unclassified

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Estratégia supramolecular para a nanotecnologia

Araki¹

2007

Quím. Nova

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SUPRAMOLECULAR APPROACH TO NANOTECHNOLOGY. Brazilian science is evolving rapidly and steadly in the last 10 years, reaching the 15º place in the international ranking. Research in nanotechnology is following a similar way generating new scientific and technological knowledge in several frontiers but specially in the interfaces of two or more areas, where Chemistry is consolidating itself as a central science. In this context, the supramolecular approach is a very promissing one because it allows the build-up of a chemical inteligence using all the sistematized knowledge for the design and development of new nanomaterials and products. The great challenge of Chemistry is not decrease the dimensionality of the materials but instead find ways to increase the dimensionality and structural complexity keeping strict control on the interactions between the components, in order to generate materials with new properties and functionalities. Unfortunately, the current vigorous advancement of scientific research has not been followed by the transformation of such knowhow into patents and produts. Therefore much efforts should be devoted to build a national science and technology program, joining all the segments of the society involved in the technological development (university, institutes of technological research, industry and government) in order to promote the furtherance of the Brazilian technological base. Only in this way it is possible to evolve to a technological society capable to transform the scientific knowledge into wealthy, thus sustaining the socioeconomic development of the country.Keywords: nanotechnology; supramolecular approach; nanomaterials. INTRODUÇÃOCiência e tecnologia sempre andam lado a lado e dependem do desenvolvimento técnico dos instrumentos de medida, de observação, de análise e de produção, que são utilizados de maneira integrada para desenvolver novos produtos. Assim, os estudos da física e da biologia baseavam-se em materiais de dimensões macroscópicas. Porém, o aperfeiçoamento e desenvolvimento constante da instrumentação, principalmente a partir de meados do século passado, tornaram possível o estudo dos materiais em escalas cada vez menores, chegando à escala nano (Figura 1). Essa estratégia possibilitou a diminuição progressiva dos dispositivos de estado sólido, provocando um aumento extraordinário do número de dispositivos que podem ser acomodados numa mesma área. Outra conseqüência foi a diminuição do consumo de energia e a possibilidade de integração de um número sempre crescente de dispositivos, tal que a capacidade dos processadores dobrou a cada 24 meses (Lei de Moore) nos últi-mos 40 anos. Atualmente um processador de última geração como o Intel Itanium de duplo processador contém mais de 1x10 9 transistores (http://www.intel.com/technology/mooreslaw/index.htm).Comportamento similar pode ser observado no caso da biologia, que iniciou com a sistematização dos organismos vivos pelos seus fenótipos e atualmente estuda a base molecular dos processos biológicos e de sua expressão....

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Section: Principais Linhas E Contribuiçõesunclassified

Section: Figura 2 A) Gráficos Mostrando O Número De Publicações E B)unclassified

Estratégia supramolecular para a nanotecnologia

Araki¹

2007

Quím. Nova

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“…Here attached dye rather than the semiconductor itself are the absorbing species and the processes of the light absorption and charge separation are separated by the semiconductor/sensitizer interface preventing electron hole recombination. 11,12 In the present work, ZnO films are coated on FTO substrate by doctor blade method. Conductivity (σ d ) and photoconductivity (σ ph ) are important factors in view of a use of the porous materials in DSSCs, since electron transport in these devices plays a decisive role for the electron collection efficiency and therefore for the overall efficiency.…”

Section: Introductionmentioning

confidence: 99%

SYNTHESIS AND PHOTOSENSITIVE PERFORMANCE OF NANOSTRUCTURED ZnO/DYE HYBRID FILM FOR ENERGY CONVERSION

Rani

Tripathi

2013

Int. J. Mod. Phys. Conf. Ser.

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The ZnO film prepared by doctor blade method are highly porous in presence of structure directing agent PEG and then can be easily sensitized by various molecules. In the present work, the nanostructured ZnO/dye hybrid film prepared by doctor blade method has been investigated in conductivity and photoconductivity measurements in view of applications in dye-sensitized solar cells (DSSC) and in optoelectronics, since electron transport in these devices plays a decisive role for the electron collection efficiency and therefore for the overall efficiency. The absorption of ZnO film sensitized by Rose Bengal dye (RB) has been studied by UV spectroscopy which indicates that after the dye is adsorbed on the ZnO electrode, its absorption spectra showed redshift in the peak position compared to the absorbance spectra of dye in ethanol. Highly porous ZnO films are found to have high dark conductivity, probably because of a higher n-doping, which is due to higher concentration of Zn atoms in the film. On the other hand, ZnO/RB hybrid film is found to show a much higher sensitivity to illumination with visible light in photoconductivity measurements due to a higher absolute photoconductivity and lower conductivity in the dark.

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“…Dye sensitization of semiconductor with a wide band-gap has provided a successful solution to extending the absorption range of the cells to long wavelength region. This approach also presents advantages over the direct band-toband excitation in conventional solar cells, since attached dyes, rather than the semiconductor itself, are the absorbing species (Garcia et al, 2000). Importantly, light absorption and charge carrier transport are separated, and the charge separation takes place at the interface between semiconductor and sensitizer, preventing electron-hole recombination.…”

Section: Introductionmentioning

confidence: 99%