Christophe Voisin's Home Page

Professor at Université Paris Diderot (Paris 7),
Researcher at laboratoire Pierre Aigrain, Physics Department, Ecole Normale Supérieure.



Address :

Laboratoire Pierre Aigrain
Ecole Normale Supérieure
24 rue Lhomond
F-75005 Paris
tel : +33 1 44 32 38 45
fax : +33 1 44 32 38 40
christophe.voisin at lpa.ens.fr
Room : D15
Lab : R18/GH14 (3364/3855)


Curriculum Vitae

Research

My research is basically dedicated to the optical properties of nano-structures : electronic structure, effects of confinement, dephasing processes and electronic interaction dynamics at a sub-picosecond time-scale. These topics are investigated by means of micro-photoluminescence (┬ÁPL), excitation of the photoluminescence (PLE), Raman and Rayleigh spectroscopies and nonlinear femtosecond pump-probe spectroscopies. The common point of these diverse pieces of work is to explore the dynamics of photo-excited electrons and phonons and to single out the role of the nano-structuration on their relaxation. In addition, I developped innovative experimental methods to single out the intrinsic response of the nano-objects from the effects related to the interactions of the object with its environment. This topic is very central in nano-sciences since nano-objects are characterized by a large surface/volume ratio. It concerns both fundamental aspects (since those interactions with the environment may hinder the observation of the intrinsic sought effects) and applications since nano-materials must be in a matrix for most applications. Although my research has been focusing on carbon nanotubes for the last five years, my successive research works dealt with various materials and confinement types. Optics is a natural technique for the investigation of semi-conductors that I studied in their one-dimensional (carbon nanotubes) and zero-dimensional (quantum dots) flavors. We developed state-of-the-art experimental setups combining high spatial and spectral resolutions to study the dephasing and non-radiative recombination mechanisms that are the most limiting parameters for the applications of these structures. Optical tools are less popular for the investigation of metals, nevertheless they turned out to be very powerful for the study of electron dynamics in zero and two dimensional metallic nanostructures. My PhD thesis was dedicated to noble metal nanoparticles and their electronic and vibrational properties.
For details on my reaserch, check the web page of the Optics team of LPA.

Teaching

Scientific outreach