All-carbon platforms for highly efficient molecular wire-coupled dye-sensitized solar cells
Mesoscopic electrode materials.
Abstract: The proposed project comes with a visionary approach, aiming at development of highly efficient molecular-wire charge transfer platform to be used in a novel generation thin film dye-sensitized solar cells fabricated via organic chemistry routes. The proposed technology combines the assembled dye monolayer s, linked with organic molecular wires to semiconducting thin film deposited on optically transparent substrates. Current organic photovoltaic (OPV) cell designs made a significant step towards low cost solar cells technology, however in order to be competitive with Si and CIGs technologies, OPVs have to demonstrate long term stability and power conversion efficiencies above 10% The highest reported power conversion efficiency for OPV device based on bulk heterojunction device with PCBM and low band gap conjugated polymers is today 6.4% but this system seems reaching its limit. Offsets in the energetics of these systems lead to large internal energy losses. The dye-sensitized solar cells (DSC) reach the efficiency above 11% but the problems with the stability of the electrolyte are the current bottleneck. The MOLESOL comes with a novel concept of hybrid device combining the advantages of both concepts (i.e. dye coupled with organic molecular wire to a conductive electrode). This concept will lead to stable cells with enhanced conversion efficiency based on: Reduction of critical length for the charge collection generated in the dye monolayer by the inorganic bottom electrode, using short molecular wires compatible with exciton diffusion length. Replacing current inorganic ITO/FTO (n-type) layer by novel transparent wide band p-type semiconductor with a possibility of engineering the surface workfunction and leading to perfect matching between HOMO of the dye layer and the valence band of semiconductors, allowing larger Voc.