Dr. Xavier Rocquefelte
Phone: +33 (0)2 40 37 39 97
Last updated : 03/12/2009
- Electronic Structures
- DFT modelling combined to experimental techniques (XRD, NMR, IR/Raman, EELS, …)
- Optical properties modelling (optical channel concept)
- Defect Chemistry of phosphorescent, photocatalytic and photovoltaic materials
Member of : Summary:
I’m working for a Materials Science Institute, “Institut des Matériaux Jean Rouxel (CNRS-Université UMR 6502)”, in Nantes, near the west coast of France. My work is mainly concerned with computer modelling of energy-related materials, using state-of-the-art theories to properly simulate the related X-ray (XAS, XPS), dielectric (EELS, Ellipsometry), vibrational (IR/Raman) and nuclear (RMN) signals. More specifically, I am developing a strategy combining DFT modelling with experiments to elucidate the defects chemistry in photo-active materials (photovoltaic, phosphorescent and photocatalytic).
This theoretical activity is in close contact with experiments, with a permanent dialog between the more recent theoretical and experimental developments in the field of Materials Science.
- June 28 - July 1st, 2011: 18th WIEN2k Workshop (Invited speaker)
- July 5 – July 10, 2010: 17th WIEN2k Workshop and 1st ICAMM conference (Chairman)
X. Rocquefelte, K. Schwarz, P. Blaha , Comment on “High-Tc Ferroelectricity Emerging from Magnetic Degeneracy in Cupric Oxide” , Phys. Rev. Lett. 107 , 239701 (2011).
Key aspects: Magnetic exchange, mapping analysis, highly-correlated electrons, hybrid functional.
A. Lafond, X. Rocquefelte, M. Paris, C. Guillot-Deudon and V. Jouenne, Crystal Chemistry and Electronic Structures of the Photovoltaic Buffer Layer, (In1-xAlx)2S3, Chem. Mater. , ASAP (2011).
Key aspects: photovoltaic materials, defect chemistry, NMR spectroscopy,
J . Lhoste, X. Rocquefelte, K. Adil, R. Dessapt, S. Jobic, M. Leblanc, V. Maisonneuve, and M. Bujoli-Doeuff, A New Organic-Inorganic Hybrid Oxyfluorotitanate [Hgua]2 (Ti5 O5 F12) as a Transparent UV Filter , Inorg. Chem.50, 5671–5678 (2011)
Key aspects: UV absorber, optical properties simulation, hybrid organic-inorganic materials
G. Denis, X. Rocquefelte, P. Deniard, M.-H. Whangbo, S. Jobic, Site preference of Eu2+ dopants in the (Ba,Sr)13-x Al22-2x Si 10+2x0 66 phosphor and its effect on the luminescence properties: Density functional investigation , J. Mater. Chem., DOI: 10.1039/b914374b (2009)
Key aspects: Phosphorescent materials, defect chemistry, site preference of dopant ions, DFT atomic relaxation.
X. Rocquefelte, S.E. Boulfelfel,. M. Ben Yahia, J. Bauer, J.-Y. Saillard,. J.-F. Halet, Structural preference versus metal within the MB2 C2 (M = Mg, Sc, Ca, Y, Ln) phases: The coloring problem revisited by DFT calculations, Angew. Chem. 46, 7542 (2005)
Key aspects: Structural resolution based on the combination of Nuclear Magnetic Resonance spectroscopy and DFT modelling.
X. Rocquefelte , F. Goubin, H.-J. Koo, M.-H. Whangbo, S. Jobic, Investigation of the origin of the empirical relationship between refractive index and density on the basis of first principles calculations for the refractive indices of various TiO2 phases , Inorg. Chem. 43,2246 (2004).
Key aspects: Coupling of EELS spectroscopy and DFT modelling, proposition of the new concept of “optical channel” to tune the optical properties of solid state materials.
- Full-Researcher position, CNRS delegation (01/2010-09/2010) ,
- Assistant-Professor position, Institut des Matériaux Jean Rouxel (since 2005),
- Temporary Teaching&Researcher fellowship, LCSIM (CNRS UMR6511 Rennes) (2004-2005),
- Temporary Researcher fellowship (AUVIB industrial project) , Institut des Matériaux Jean Rouxel (2002-2004),
- Marie Curie Researcher fellowship, Louvain-La-Neuve University (2001-2004),
- PhD Theoretical Chemistry in Material Science, University of Nantes (2001).
Cover page of Inorganic Chemistry for the theoretical investigation of the TiO2 optical properties. Frontispiece at the beginning of the communication section of Angewandte Chemie for solving the B/C ordering in MB2C2
(M = Mg, Sc, Ca, Y, Ln) phases.