Two organolead halide perovskite nanocrystals, CH3NH3PbBr3 and CH3NH3PbI3, were found to efficiently sensitize TiO2 for visible-light conversion in photoelectrochemical cells. When self-assembled on mesoporous TiO2 films, the nanocrystalline perovskites exhibit strong band-gap absorptions as semiconductors. The CH3NH3PbI3-based photocell with spectral sensitivity of up to 800 nm yielded a solar energy conversion efficiency of 3.8%. The CH3NH3PbBr3-based cell showed a high photovoltage of 0.96 V with an external quantum conversion efficiency of 65%.

Organometal Halide Perovskites as Visible-Light Sensitizers for Photovoltaic Cells

Titanium Dioxide Nanomaterials: Synthesis, Properties, Modifications, and Applications

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 interest in nanoscale materials stems from the fact that new properties are acquired at this length scale and, equally important, that these properties * To whom correspondence should be addressed. Phone, 404-8940292; fax, 404-894-0294; e-mail, mostafa.el-sayed@ chemistry.gatech.edu. † Case Western Reserve UniversitysMillis 2258. ‡ Phone, 216-368-5918; fax, 216-368-3006; e-mail, burda@case.edu. § Georgia Institute of Technology. 1025 Chem. Rev. 2005, 105, 1025−1102

Chemistry and properties of nanocrystals of different shapes.

2.1. Solvents 4307 2.1.1. Propylene Carbonate (PC) 4308 2.1.2. Ethers 4308 2.1.3. Ethylene Carbonate (EC) 4309 2.1.4. Linear Dialkyl Carbonates 4310 2.2. Lithium Salts 4310 2.2.1. Lithium Perchlorate (LiClO4) 4311 2.2.2. Lithium Hexafluoroarsenate (LiAsF6) 4312 2.2.3. Lithium Tetrafluoroborate (LiBF4) 4312 2.2.4. Lithium Trifluoromethanesulfonate (LiTf) 4312 2.2.5. Lithium Bis(trifluoromethanesulfonyl)imide (LiIm) and Its Derivatives 4313

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Nonaqueous liquid electrolytes for lithium-based rechargeable batteries.

Nanostructured materials are used in many photoelectrochemical applications primarily due to surface area considerations. These materials are usually applied as nanoporous electrodes, which are made by the sintering of nanosize semiconductors on a conductive substrate. A surface area factor greater than one thousand produces a significant enhancement of surface processes. However, the porous geometry induces special characteristics that significantly differentiate nanoporous electrodes from their compact analogues. These characteristics must be considered when using these electrodes either in applications or as a research tool. This chapter discusses basic concepts related to the photoelectrochemistry of nanoporous electrodes. A major part of the chapter is devoted to dye sensitized solar cells, one of the most successful examples of the utilization of nanostructured materials in photoelectrochemistry.

Nanostructured Materials in Photoelectrochemical Applications

The invention disclosed herein is directed a mesoporous surface being coated with semiconductor nanoparticles. The coating is formed by employing electrophoretic deposition (EPD) of ex situ semiconductor nanoparticles. The mesoporous surface can be integrated in photoelectronic devices, particularly quantum dot (QD) sensitized solar cells (QDSSC).

Nanoparticle-coated mesoporous surfaces and uses thereof

The invention relates to a method for the preparation of stable suspensions of metal oxide nanopareticles, in which uncharged metal oxide nanoparticles are first treated with a non-ionic surfactant in a polar organic solvent under certain conditions, and the suspension obtained is then treated with a charging solution. The suspensions of the invention can be used for preparation of high quality metal oxide films by electrophoresis deposition (EPD).

Method for preparation of stable metal oxide nanoparticles suspensions

A system is presented for collecting and concentrating light from a moving light source (e.g. the Sun). The system comprises at least one anamorphic optical element, defining an optical axis and a projection region and having a predetermined effective aperture which defines primary and secondary axes. The effective aperture is configured for collection of optical radiation arriving from a predetermined solid collection angle defining a first range of angles with respect to a plane spanned by said optical and primary axes. The anamorphic optical element is configured such that light passing through said effective aperture within a predetermined first range of angles within said predetermined solid collection angle is concentrated onto at least a part of said projection region. At least one receiver aperture is defined by at least a part of said projection region.

Collector and concentrator of solar radiation

To the Editor – We face, after over two decades of not-so-benign neglect, a serious deficit of alternative-energy (AE)-oriented basic science researchers. Indeed, a major problem in meeting the global energy challenge may well be the paucity of top scientists pursuing AE-related research problems. This deficit has the potential to self-proliferate, because a limited core of experienced researchers will encourage a limited group of talented students and post-docs to seek research opportunities in AE research in the future. In early September 2007, Israeli scientists performed an ‘experiment’ to break out of this pattern: A selected group of 24 of the nation’s top, final-year PhD students from all areas of physical, life and engineering sciences, assembled in a tranquil Galilee mountain location, along with 20 senior Israeli and foreign scientists, who are all experts in various aspects of AE or in directly relevant core areas. Most students didn’t have any previous AE experience, but had showed a clear interest in the subject. The meeting (www.weizmann.ac.il/conferences/ASEO/) funded by the Bat-Sheva de Rothschild foundation, with support from the Safed foundation, the Mizpe Yamim hotel and our parent institutions, had a rather conventional name: ‘Alternative, Sustainable Energy Options’. But there was nothing conventional about the programme and atmosphere of the meeting. After a packed two-day crash course of general presentations by experts, explaining AE issues “from fundamentals to engineering”, the group split into smaller sets and was introduced to systematic innovative thinking approaches. In each of the smaller groups, dynamic discussions and brain-storming sessions developed, interspersed by intense tutoring by the senior scientists in their areas of expertise (see Fig. 1). The final discussion sessions were led by students on topics they proposed, such as: “is there really a crisis in energy resources?”; “is there an ideal electrical storage approach?”; and “theoretical limit(s) of biological solutions to the energy challenge”. Students and lecturers admitted to being initially sceptical about the nonconventional seminar programme, but the ‘pleasant week in a nice place’ expectations were surpassed by intense days of discussions, focused personal tutoring and plenty of lively arguments. “The seminar made us aware of, and knowledgeable about, the energy challenges and related worldwide scientific research, but it also allowed us to form our own opinions about directions for fruitful avenues of research for possible new approaches to AE,” was the response from one student. How large a new cadre of energy researchers will develop as a result of the meeting remains to be seen, but it seems clear that its first seeds could have been planted on a beautiful, peaceful Galilee mountain side. Our message to all our colleagues is that investing some time and effort now in such projects should help us all to a brighter future, by introducing a new generation to AE research.

Arie Zaban

Papers

Nanostructured Materials in Photoelectrochemical Applications

Nanoparticle-coated mesoporous surfaces and uses thereof

Method for preparation of stable metal oxide nanoparticles suspensions

Collector and concentrator of solar radiation

Human resources for future alternative-energy research