Sainte-Foy-lès-Lyon, France
Sainte-Foy-lès-Lyon, France
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Audebert P.,Ecole Normale Superieure de Cachan | Deleporte E.,LAC | Even J.,FOTON | Katan C.,ISCR | Odobel F.,CEISAM
Actualite Chimique | Year: 2015

One of the major challenges related to the design, development and manufacture of photovoltaic devices remains the ability to deliver low-cost, efficient and stable technologies for solar-to-electricity conversion. This paper summarises recent progresses made within three sectors that are most likely to afford cheap production costs: organic cells, dye sensitised solar cells (DSSC), and perovskite cells. The later has recently opened a new route and attracts currently a tremendous research effort. Each section includes a brief historical overview and the basic concepts of organic and DSSC architectures are given. Next, the latest developments for each of the three types of cell technology are discussed. One of the main concerns in both all organic and dye sensitised photovoltaic devices is advanced design of molecular systems combining highperformance with ease of processing. However, in a photovoltaic device the synergy between individual components calls for an integrated approach. The same holds for the new class of solar cells based on mixed organic-inorganic halide perovskites. It happens that despite the outstanding improvement in cell performance in terms of conversion efficiency made within a couple of years, there is still need for fundamental understanding of what makes hybrid perovskites so successful in that respect. Knowledge gained by more than two decades of active research in materials chemistry and solid-state physics concepts should be combined to solve technological bottlenecks.

Guillory X.,Jean Rouxel Institute | Guillory X.,French Research Institute for Exploitation of the Sea | Tessier A.,CEISAM | Gratien G.-O.,Jean Rouxel Institute | And 5 more authors.
RSC Advances | Year: 2016

For hybrid materials, the relationship between the macroscopic properties and the molecular structures and dynamics at the microscopic between the organic and inorganic components level is crucial. The characterization of these components as well as their reactivity have to be emphasized in order to design and synthesize improved hybrids. We report herein the first comprehensive study of the reactivity in organic media of (3-glycidyloxypropyl)trialkoxysilanes, widely used as precursors in sol-gel hybrid synthesis, towards common nucleophiles. Thorough investigations of the reactions allowed us to draw clear conclusions about the reactivities of both epoxide and alkoxysilane functions. Furthermore, the nucleophile properties and the method of activations have a great influence on the reaction outcomes, and unexpected results were found in some cases. The importance of the nature of the alkoxy residues (methoxy, ethoxy...) was also investigated highlighting chemoselective reactions on glycidyl silane derivatives (GPTMS, GPTES and PECS) and opening a new library of original sol-gel precursors. © 2016 The Royal Society of Chemistry.

Karlsson S.,Uppsala University | Boixel J.,CEISAM | Pellegrin Y.,CEISAM | Blart E.,CEISAM | And 3 more authors.
Faraday Discussions | Year: 2012

To achieve artificial photosynthesis it is necessary to couple the single-electron event of photoinduced charge separation with the multi-electron reactions of fuel formation and water splitting. Therefore, several rounds of light-induced charge separation are required to accumulate enough redox equivalents at the catalytic sites for the target chemistry to occur, without any sacrificial donors or acceptors other than the catalytic substrates. Herein, we discuss the challenges of such accumulative electron transfer in molecular systems. We present a series of closely related systems base on a Ru II-polypyridine photosensitizer with appended triaryl-amine or oligo-triaryl-amine donors, linked to nanoporous TiO 2 as the acceptor. One of the systems, based on dye 4, shows efficient accumulative electron transfer in high overall yield resulting in the formation of a two-electron charge-separated state upon successive excitation by two photons. In contrast, the other systems do not show accumulative electron transfer because of different competing reactions. This illustrates the difficulties in designing successful systems for this still largely unexplored type of reaction scheme. © 2012 The Royal Society of Chemistry.

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