Search

26th European Photovoltaic Solar Energy Conference and Exhibition; 533-537, The experimental isolation of graphene by micromechanical cleavage of highly oriented pyrolytic graphite (HOPG) has stimulated much experimental and theoretical research. In the last few years, a great deal of work has been dedicated to test how the theoretical predictions match the experimentally determined properties of graphene. Recent works have shown that graphene sheets (GS) deposited on n-type Si wafer to give Schottky barrier solar cells (SBSC) allow to achieve efficiencies up to 1.5%. Our paper reports a study about the final performances of graphene-on-semiconductor Schottky junction solar cells showing the potentiality of this kind of device. A generalized equivalent circuit model of graphene based SBSC is presented to simulate the device behavior: the circuital parameters used in the model are strictly dependent on the physical properties of the GS and of the semiconductor which form the Schottky junction. Electrical Capacitance- Voltage (CV) characterization performed on some “ad hoc” realized structures, have been used to obtain the experimental value of some important physical parameters used in the calculations.

24th European Photovoltaic Solar Energy Conference, 21-25 September 2009, Hamburg, Germany; 1687-1689, The necessity of cost-reduction for solar generated electricity has evidenced photovoltaic concentrators as promising technology for the PV industry. One of the most fundamental steps in the fabrication process of high efficiency c- Si solar cells designed for concentrating systems is the realization of a good passivation oxide on the silicon surface. In this work we investigate the properties of rapid thermal oxide (RTO) to be used as an alternative passivation layer to the more expensive classical thermal oxide which has been used until now. The effects of rapid thermal annealing in forming gas (RTA in FG) have also been tested. The investigation of the electrical properties of the silicon/oxide interface to get informations about the oxide passivation quality has been done through capacitance-voltage (CV) and capacitance-frequency (CF) characterization of some “ad hoc” realized MOS structures.