Ultra-sensitive graphene based photo-detector.
The optical properties of carbon nanotubes are very original, marked in particular by giant excitonic effects due to their one-dimensional character. Recent techniques such as micro-photoluminescence now allow to study these objects at the scale of a single molecule. Moreover, these nanotubes and their cousins the graphene ribbons can be integrated as the channel of devices such as nano-transistors. These devices inherit unique characteristics, in particular due to the quasi-ballistic electron motion. The laboratory Pierre Aigrain, ENS has recently developed a research topic at the interface between these two themes (optics/electronics) that are both well established in the laboratory: the point is to understand how light can modulate the electronic properties of transistors or conversely how the microscopic operating of these transistors can generate specific optical signatures (luminescence, Raman ...). In particular, the measurement of the spectrum of current fluctuations at high frequencies (GHz) provides information on the energy distribution of electrons while measuring Raman scattering spectra provides information on the coupling of electrons with different phonon mode. The student will participate in the launching of this activity by learning the techniques of optical measurements on single nanotube or graphene ribbon, the techniques of nanofabrication in cleanroom and by participating in the first ultra-sensitive electronic measurements at high frequency.
Methods and techniques : Micro-photoluminescence spectroscopy, Raman spectroscopy, lasers, cryogeny, clean room, vacuum techniques, radio frequency/low noise electronic measurements.
Contact : Christophe Voisin