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Michael Grätzel

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
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Journal ArticleDOI
TL;DR: In this article, the phase distribution and kinetics of phase exchange were derived for TTF in aqueous/CTAC micellar solution, comprising cyclic voltammetry and rotating disc kinetic studies.

33 citations

Journal ArticleDOI
TL;DR: In this paper, the authors proposed a layered hybrid halide perovskites, which are known to be more environmentally stable than their 3D analogues, and enhanced stability is particularly relevant for Dion-Jacobson-type layered perovsites due to their high energy efficiency.
Abstract: Layered hybrid halide perovskites are known to be more environmentally stable than their 3D analogues. The enhanced stability is particularly relevant for Dion–Jacobson-type layered perovskites due...

33 citations

Journal ArticleDOI
TL;DR: In this paper, nanocrystalline Nb2O5 films were prepared by an extended sol-gel method based on the hydrolysis of a modified Nb-alkoxide precursor.
Abstract: Nanocrystalline Nb2O5 films were prepared by an extended sol-gel method. The synthesis is based on the hydrolysis of a modified Nb-alkoxide precursor. Reaction of the modified precursor (Nb(OEt)5 + 2 2,4-pentanedione) with water in ethanol leads to a homogeneous hydrolyzed solution, which is stable against precipitation of niobium oxide after evaporation of the ethanol and in the whole pH-range investigated (1–10). Autoclaving leads to amorphous gels, from which homogeneous nanocrystalline niobium oxide films of up to 15 μm can be made. During annealing crystalline phases are first observed above 500°C with fully crystalline films of orthorhombic T-phase Nb2O5 attained at 600°C. The microstructural, crystallographic, optical and photoelectrical properties of the films were characterized by means of SEM, XRD, UV-VIS spectroscopy and surface photovoltage spectroscopy, respectively.

32 citations

Journal ArticleDOI
TL;DR: In this article, the deposition of 4% molybdena has a pronounced effect on methane activation, partial oxidation to CO becoming a competing pathway, and CO is the major oxidation product if TiO2 loaded with both MoO3 and H4SiW12O40 is used as a catalyst.
Abstract: Methane is activated at room temperature and atmospheric pressure on TiO2, supported molybdena catalyst excited by band gap illumination. With pure TiO2, complete oxidation to CO2 is observed in the presence of oxygen. The deposition of 4% molybdena has a pronounced effect on methane activation, partial oxidation to CO becoming a competing pathway. CO is the major oxidation product if TiO2 loaded with both MoO3 and H4SiW12O40 is used as a catalyst. MoO3 used alone or in conjunction -with A12O3 or SiO2 as carriers exhibits poor activity in the photoactivation of methane.

32 citations

Journal ArticleDOI
TL;DR: In this paper, a dye sensitization of wide bandgap semiconductors to improve their spectral response to visible light has been discussed and three examples from their recent work have been presented, in which the semiconductor particle surface (TiO 2 ) has been modified by adsorption of various dye molecules and by surface derivatization with ruthenium(II) complexes.

32 citations


Cited by
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08 Dec 2001-BMJ
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

Journal ArticleDOI
24 Oct 1991-Nature
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

Journal ArticleDOI
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