Author
Michael Grätzel
Other affiliations: University of California, Berkeley, Siemens Energy Sector, University of Bath ...read more
Bio: Michael Grätzel is an academic researcher from École Polytechnique Fédérale de Lausanne. The author has contributed to research in topics: Dye-sensitized solar cell & Perovskite (structure). The author has an hindex of 248, co-authored 1423 publications receiving 303599 citations. Previous affiliations of Michael Grätzel include University of California, Berkeley & Siemens Energy Sector.
Papers published on a yearly basis
Papers
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TL;DR: In this paper, the photovoltaic performance of solid-state dye-sensitized solar cells (DSCs) using a series of ullazine-based metal-free organic sensitizers and spiro-MeOTAD as a hole-transport material was investigated.
Abstract: Here we present the photovoltaic performance of solid-state dye-sensitized solar cells (DSCs) using a series of ullazine-based metal-free organic sensitizers and spiro-MeOTAD as a hole-transport material. A maximum of 4.95% power conversion efficiency measured under standard AM 1.5G illumination (100 mW cm2) was achieved with the best performing ullazine dye, and was further improved to 5.40% through co-sensitization with the triphenylamine-based organic sensitizer, D35. This study investigates the effect of the molecular structure of the ullazine sensitizer on the performance in solid-state DSCs.
38 citations
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TL;DR: In this article, a new class of ruthenium(II) complexes containing carboxylated 1,10-phenanthroline were synthesized, and the overall solar-to-electric power conversion efficincy was obtained at AM-1.5 (100 mW/cm2).
Abstract: A new class of ruthenium(II) complexes containing carboxylated 1,10-phenanthroline were synthesized. Photosensitization of nanocrystalline TiO2 electrode by bis(tetrabutylammonium)dihydronium cis-dithiocyanato bis(4,7-dicarboxy-1,10-phenanthroline)ruthenium(II) showed a high incident photon-to-current conversion efficiency (IPCE: 70% at 540 nm). The overall solar-to-electric power conversion efficincy of 6.1% was obtained at AM-1.5 (100 mW/cm2).
37 citations
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TL;DR: In this paper, band gap illumination of TiO2 (anatase) dispersions in weakly alkaline solutions of nicotinamide-adenine-dinucleotide (NAD+) leads was investigated.
Abstract: — Band gap illumination of TiO2 (anatase) dispersions in weakly alkaline solutions of nicotinamide-adenine-dinucleotide (NAD+) leads in the presence of rhodium trisbipyridyl complex [Rh(bipy)3+3], to continuous generation of biologically active cofactor NADH. Effects of pH, NAD+ and Rh(bipy)3+3 concentration on the efficiency of this photoconversion process are investigated. The reaction proceeds already in aqueous solution in the absence of external electron donors but it is enhanced significantly in the presence of 10% methanol.
37 citations
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TL;DR: In this paper, the adsorbed counterions carried by the ruthenium(II) complexes (Bu4N)2[Ru(Hdcbpy)2(NCS)2] (1), Bu4N4 [Ru(dcbgy)2NCS] (2), and Ru(H2dcbphy)2 NCS) 2] (3) on TiO2 have been carried out by using thermoanalytical techniques, NMR, and ATR−FTIR spectroscopic methods.
Abstract: Adsorption studies of counterions carried by the ruthenium(II) complexes (Bu4N)2[Ru(Hdcbpy)2(NCS)2] (1), (Bu4N)4[Ru(dcbpy)2(NCS)2] (2), and [Ru(H2dcbpy)2(NCS)2] (3) (dcbpy = 2,2‘-bipyridyl-4,4‘-dicarboxylate, Bu4N = tetrabutylammonium) on TiO2 have been carried out by using thermoanalytical techniques, NMR, and ATR−FTIR spectroscopic methods. The thermogravimetric analysis (TGA) data of the adsorbed complexes 1 and 2 on TiO2 show the presence of 1 and ≤1.3 cations coadsorbed per ruthenium center, respectively. These complexes in the adsorbed state on TiO2 show remarkable stability in air atmospheres at high temperatures up to 180 °C. The only process that is observed at lower temperatures is the dehydration, which occurs between 40 and 110 °C. At high temperature the processes are deamination of the tetrabutylammonium counterion as well as decarboxylation and decomposition of the complex between 200 and 400 °C. The NMR data of the desorbed complexes 1 and 2 from the TiO2 surface show the presence of 1 and...
37 citations
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TL;DR: In this paper, stable quasi-solid-state dye-sensitized solar cells (DSCs) were fabricated using room-temperature molten salts (1-methyl-3-hexyl-imidazolium iodide), and a series of diamine derivatives with different lengths of alkyl chain as low molecular mass organogelators (LMOGs).
Abstract: Stable quasi-solid-state dye-sensitized solar cells (DSCs) were fabricated by using room-temperature molten salts (1-methyl-3-hexyl-imidazolium iodide), and a series of diamine derivatives with different lengths of alkyl chain as low molecular mass organogelators (LMOGs). The number of methylene (-CH2-) units between the two amide carbonyl groups in the gelator molecule has significant influence on the charge transport property of gel electrolyte, and the kinetic processes of the electron transport and recombination. Less compact networks of the ionic liquid gel electrolytes containing odd-numbered -CH2- gelator facilitate the diffusion of I-3(-) and I-. Also, the odd-numbered -CH2- gelators-based DSCs exhibit longer electron recombination lifetime and a higher open circuit potential (V-oc) compared with the DSCs based on even-numbered -CH2- gelators; consequently, the photovoltaic performances of DSCs based on odd-numbered -CH2- gelators are much better than those even-numbered -CH2- gelators. Remarkably, the results of the accelerated aging tests showed that the ionic liquid gel electrolyte-based DSCs could retain 93%-99% of their initial photoelectric conversion efficiencies (eta) under heat at 60 degrees C, and 100% of their initial photoelectric conversion efficiencies under one sun light soaking with UV cutoff filter at 50 degrees C for 1000 h. This excellent long-term stability of quasi-solid-state DSCs is very important for application and commercialization of DSCs.
37 citations
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TL;DR: There is, I think, something ethereal about i —the square root of minus one, which seems an odd beast at that time—an intruder hovering on the edge of reality.
Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.
Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …
33,785 citations
01 May 1993
TL;DR: Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems.
Abstract: Three parallel algorithms for classical molecular dynamics are presented. The first assigns each processor a fixed subset of atoms; the second assigns each a fixed subset of inter-atomic forces to compute; the third assigns each a fixed spatial region. The algorithms are suitable for molecular dynamics models which can be difficult to parallelize efficiently—those with short-range forces where the neighbors of each atom change rapidly. They can be implemented on any distributed-memory parallel machine which allows for message-passing of data between independently executing processors. The algorithms are tested on a standard Lennard-Jones benchmark problem for system sizes ranging from 500 to 100,000,000 atoms on several parallel supercomputers--the nCUBE 2, Intel iPSC/860 and Paragon, and Cray T3D. Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems. For large problems, the spatial algorithm achieves parallel efficiencies of 90% and a 1840-node Intel Paragon performs up to 165 faster than a single Cray C9O processor. Trade-offs between the three algorithms and guidelines for adapting them to more complex molecular dynamics simulations are also discussed.
29,323 citations
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TL;DR: In this article, the authors describe a photovoltaic cell, created from low-to medium-purity materials through low-cost processes, which exhibits a commercially realistic energy-conversion efficiency.
Abstract: THE large-scale use of photovoltaic devices for electricity generation is prohibitively expensive at present: generation from existing commercial devices costs about ten times more than conventional methods1. Here we describe a photovoltaic cell, created from low-to medium-purity materials through low-cost processes, which exhibits a commercially realistic energy-conversion efficiency. The device is based on a 10-µm-thick, optically transparent film of titanium dioxide particles a few nanometres in size, coated with a monolayer of a charge-transfer dye to sensitize the film for light harvesting. Because of the high surface area of the semiconductor film and the ideal spectral characteristics of the dye, the device harvests a high proportion of the incident solar energy flux (46%) and shows exceptionally high efficiencies for the conversion of incident photons to electrical current (more than 80%). The overall light-to-electric energy conversion yield is 7.1-7.9% in simulated solar light and 12% in diffuse daylight. The large current densities (greater than 12 mA cm-2) and exceptional stability (sustaining at least five million turnovers without decomposition), as well as the low cost, make practical applications feasible.
26,457 citations
28 Jul 2005
TL;DR: PfPMP1)与感染红细胞、树突状组胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作�ly.
Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1(PfPMP1)与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员,通过启动转录不同的var基因变异体为抗原变异提供了分子基础。
18,940 citations
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TL;DR: The slow pace of hazardous waste remediation at military installations around the world is causing a serious delay in conversion of many of these facilities to civilian uses as discussed by the authors, which is a serious problem.
Abstract: The civilian, commercial, and defense sectors of most advanced industrialized nations are faced with a tremendous set of environmental problems related to the remediation of hazardous wastes, contaminated groundwaters, and the control of toxic air contaminants. For example, the slow pace of hazardous waste remediation at military installations around the world is causing a serious delay in conversion of many of these facilities to civilian uses. Over the last 10 years problems related to hazardous waste remediation have emerged as a high national and international priority.
17,188 citations