TIME RESOLVED OPTICAL MEASUREMENTS ON CARBON NANOTUBES STRUCTURES FOR PHOTOVOLTAIC APPLICATIONS

With their intriguing electronic and optical properties carbon nanotubes are promising materials for future optoelectronics and photovoltaic applications. Recently single walled (SWCNT) and multi walled carbon nanotubes (MWCNT) aggregates were employed in hybrid solar cells . Despite the promising results the photoexcited carriers behavior in these novel devices is not fully understood . In this thesis, using ultrafast time-resolved optical spectroscopy, we investigate the carriers relaxation dynamics in various SWCNT and MWCNT architectures with potential photovoltaic applications. In particular, using time resolved transient reflectivity, we detect the signature of the charge transfer process taking place at the interface of a SWCNT / n-doped Silicon heterojunction solar cell on a few picosecond time scale