The photo conversion efficiencies of the 1st and 2nd generat ion photovoltaic solar cells are limited by the physical phenomena involved during the photo-conversion processes. An upper limit around 30% has been predicted for a monojunction silicon solar cell. In this work, we study 3rd generation solar cells named rectenna which could direct ly convert visible and infrared light into DC current. The rectenna technology is at odds with the actual photovoltaic technologies, since it is not based on the use of semi-conducting materials.<p> </p> We study a rectenna architecture consist ing of plasmonic nano-antennas associated with rectifying self assembled molecular diodes. We first opt imized the geometry of plasmonic nano-antennas using an FDTD method. The optimal antennas are then realized using a nano-imprint process and associated with self assembled molecular diodes in 11- ferrocenyl-undecanethiol. Finally, The I(V) characterist ics in darkness of the rectennas has been carried out using an STM. The molecular diodes exhibit averaged rect ification ratios of 5.
Metal-Insulator-Metal (MIM) and Insulator-Metal (IM) sub-wavelength arrays are studied to perform filtering in Visible (VIS) and Near-Infrared (NIR) respectively. We investigate the MIM sub wavelength pattern using CMOS compatible materials like silicon nitride (SiN) core and aluminum (Al) metal for visible color filtering, and IM sub wavelength array with the same materials for near- infrared filtering using Rigorous Coupled Wave Analysis (RCWA). Transmission as high as 50 % is observed for VIS-filters, while for NIR filters maximum transmissions of 80% is observed. Metallic absorption in Infrared is significantly reduced using IM structure. Enhancement in Infrared transmission by factor of 1.5 is observed upon using IM structure instead of MIM structure. Blue shift in transmission spectra is observed with increase in roundness of the patch corners. Angular tolerance of ± 20° in incidence is observed for the arrays studied.