Metal nanoparticles-Graphene hybrids for photovoltaics

A new class of photovoltaic devices including graphene and plasmonics is emerging, leading to a new trend in the development of both inorganic and organic solar cells. Graphene is mainly used as semitransparent conductive electrode and as antireflection layer. It is characterized by many magical properties, but one of the most important peculiarity of graphene is that it is an anphoteric material. Its work function can be changed by doping through charge transfer. This is a very important property to increase device efficiencies because graphene can be used as a well-matched (macd) electrode for different materials sets. Localized surface plasmon resonance tuning in metal nanoparticles is used for light trapping and enhancement of light absorption. In this context, our research aims at improving photovoltaic performance of organic polymer-based and inorganic silicon-based solar cells by: -the integration of plasmonic gold nanoparticles to harvest photon energy; nanoparticles are deposited by r.f. sputtering and their plasmon resonance tailored in real time by spectroscopic ellipsometry. -the integration of graphene as semitransparent contact; the graphene is grown by CVD on Ni and Cu and then transferred on a large variety of materials including plastics and solar cells.