Photovoltaic harvesters integrated with electrochemical double layer capacitors: novel approaches

Here we present our latest works related to the integration of dye sensitized solar cells/modules (DSSCs/DSSMs) and electrochemical double layer capacitors (EDLCs). In particular, we propose the integration of a W-type 4 serially connected DSSM and an EDLC employing N-butyl-N-methylpyrrolidiniumbis(trifluoromethanesulfonyl)imide (Pyr14TFSI) as electrolyte. The connection of the two sections enables to obtain the highest voltage ever attained to date for a photo-capacitor. The same compact harvesting and storage (HS) device structure is also obtained employing an all solid state electrolyte for the EDLC section, namely a mixture of polyethylene oxide (PEO) and Pyr14TFSI. These two HS devices are the only examples present in literature dealing with stable and reliable high voltage (2.45 V) photo-capacitors. Then, we propose the utilization of a novel polymer-based platform for the fabrication of an innovative self-powered device integrating energy harvesting and storage sections. The multifunctional polymeric layer, fabricated with two ethoxylated sections and a perfluorinated segment in between, acting as barrier, is obtained by oxygen-inhibited UV-light crosslinking procedure. The resulting photocapacitor present a planar architecture significantly simplified if compared to other recently proposed solutions. The overall conversion and storage efficiency is 3.72%, which is a notable value for DSSC-EDLC harvesting-storage devices literature.