Institution
University of Rennes
Education•Rennes, France•
About: University of Rennes is a education organization based out in Rennes, France. It is known for research contribution in the topics: Population & Catalysis. The organization has 18404 authors who have published 40374 publications receiving 995327 citations.
Papers published on a yearly basis
Papers
More filters
••
TL;DR: A combination of synthetic chemistry, crystallography, and spectroscopy was used to obtain and identify the thickest 2D halide perovskite characterized to date, having seven layers, and report the effective synthesis of the highest iodide n-members yet.
Abstract: In the fast-evolving field of halide perovskite semiconductors, the 2D perovskites (A′)2(A)n−1MnX3n+1 [where A = Cs+, CH3NH3+, HC(NH2)2+; A′ = ammonium cation acting as spacer; M = Ge2+, Sn2+, Pb2+; and X = Cl−, Br−, I−] have recently made a critical entry. The n value defines the thickness of the 2D layers, which controls the optical and electronic properties. The 2D perovskites have demonstrated preliminary optoelectronic device lifetime superior to their 3D counterparts. They have also attracted fundamental interest as solution-processed quantum wells with structural and physical properties tunable via chemical composition, notably by the n value defining the perovskite layer thickness. The higher members (n > 5) have not been documented, and there are important scientific questions underlying fundamental limits for n. To develop and utilize these materials in technology, it is imperative to understand their thermodynamic stability, fundamental synthetic limitations, and the derived structure–function relationships. We report the effective synthesis of the highest iodide n-members yet, namely (CH3(CH2)2NH3)2(CH3NH3)5Pb6I19 (n = 6) and (CH3(CH2)2NH3)2(CH3NH3)6Pb7I22 (n = 7), and confirm the crystal structure with single-crystal X-ray diffraction, and provide indirect evidence for “(CH3(CH2)2NH3)2(CH3NH3)8Pb9I28” (“n = 9”). Direct HCl solution calorimetric measurements show the compounds with n > 7 have unfavorable enthalpies of formation (ΔHf), suggesting the formation of higher homologs to be challenging. Finally, we report preliminary n-dependent solar cell efficiency in the range of 9–12.6% in these higher n-members, highlighting the strong promise of these materials for high-performance devices.
199 citations
••
TL;DR: In this paper, the authors deal with molecular materials resulting from the chemical and electrochemical molecular assemblies of organic and inorganic precursors such as organic donors derived from TTF.
Abstract: This paper deals with molecular materials resulting from the chemical and electrochemical molecular assemblies of organic and inorganic precursors such as organic donors derived from TTF, organic nitronyl nitroxide radicals, decamethylferrocenium, metal bis(dithiolate), metal bis(dithiolene), polyoxometalates, and hexacyanometalates. Some general aspects on molecular materials as well as constraints to design conducting and magnetic materials were recalled and supported by examples from our own contribution in the field. One of the current trends in molecular materials concerns the preparation and the study of materials combining several physical properties in a synergistic way. In this context materials with conducting and magnetic properties and also materials with spin crossover and antiferromagnetic interactions are presented.
199 citations
••
TL;DR: In this paper, it was shown that having found a geodesic segment (saddle connection) joining a pair of conical points one can find with a nonzero probability another saddle connection on S having the same direction and the same length as the initial one.
Abstract: A holomorphic 1-form on a compact Riemann surface S naturally defines a flat metric on S with cone-type singularities. We present the following surprising phenomenon: having found a geodesic segment (saddle connection) joining a pair of conical points one can find with a nonzero probability another saddle connection on S having the same direction and the same length as the initial one. A similar phenomenon is valid for the families of parallel closed geodesics.
199 citations
••
TL;DR: This study identifies a new gene involved in human ichthyoses and provides insights into the localization and function of this yet uncharacterized member of the PNPLA protein family.
Abstract: Ichthyoses comprise a heterogeneous group of genodermatoses characterized by abnormal desquamation over the whole body, for which the genetic causes of several human forms remain unknown. We used a spontaneous dog model in the golden retriever breed, which is affected by a lamellar ichthyosis resembling human autosomal recessive congenital ichthyoses (ARCI), to carry out a genome-wide association study. We identified a homozygous insertion-deletion (indel) mutation in PNPLA1 that leads to a premature stop codon in all affected golden retriever dogs. We subsequently found one missense and one nonsense mutation in the catalytic domain of human PNPLA1 in six individuals with ARCI from two families. Further experiments highlighted the importance of PNPLA1 in the formation of the epidermal lipid barrier. This study identifies a new gene involved in human ichthyoses and provides insights into the localization and function of this yet uncharacterized member of the PNPLA protein family.
199 citations
••
TL;DR: Aatite fission track (AFT) analyses of 45 bedrock samples from an E-W transect along Bhutan indicate faster long-term erosion rates outside of the rain shadow in the west (1.0−1.8 mm/yr) than inside of it in the east (0.55−0.85 mm/r).
Abstract: A fundamental objective in studies of climate-erosion-tectonics coupling is to document convincing correlation between observable indicators of these processes on the scale of a mountain range. The eastern Himalayas are a unique range to quantify the contribution of tectonics and climate to long-term erosion rates, because uniform and steady tectonics have persisted for several million years, while monsoonal precipitation patterns have varied in space and time. Specifically, the rise of the Shillong plateau, the only orographic barrier in the Himalayan foreland, has reduced the mean annual precipitation downwind in the eastern Bhutan Himalaya at the Miocene-Pliocene transition. Apatite fission-track (AFT) analyses of 45 bedrock samples from an E-W transect along Bhutan indicate faster long-term erosion rates outside of the rain shadow in the west (1.0‐1.8 mm/yr) than inside of it in the east (0.55‐0.85 mm/yr). Furthermore, an AFT vertical profile in the latter segment reveals a deceleration in erosion rates sometime after 5.9 Ma. In this drier segment of Bhutan, there are remnants of a relict landscape formed under a wetter climate that has not yet equilibrated to the present climatic conditions. Uplift and preservation of the paleolandscape are a result of a climate-induced decrease in erosion rates, rather than of an increase in rock uplift rate. This study documents not only a compelling spatial correlation between long-term erosion and precipitation rates, but also a climatically driven erosion-rate change on the scale of the eastern Himalayas, a change that, in turn, likely influences that region’s recent tectonic evolution.
198 citations
Authors
Showing all 18470 results
Name | H-index | Papers | Citations |
---|---|---|---|
Philippe Froguel | 166 | 820 | 118816 |
Bart Staels | 152 | 824 | 86638 |
Yi Yang | 143 | 2456 | 92268 |
Geoffrey Burnstock | 141 | 1488 | 99525 |
Shahrokh F. Shariat | 118 | 1637 | 58900 |
Lutz Ackermann | 116 | 669 | 45066 |
Douglas R. MacFarlane | 110 | 864 | 54236 |
Elliott H. Lieb | 107 | 512 | 57920 |
Fu-Yuan Wu | 107 | 367 | 42039 |
Didier Sornette | 104 | 1295 | 44157 |
Stefan Hild | 103 | 452 | 68228 |
Pierre I. Karakiewicz | 101 | 1207 | 40072 |
Philippe Dubois | 101 | 1098 | 48086 |
François Bondu | 100 | 440 | 69284 |
Jean-Michel Savéant | 98 | 517 | 33518 |