Dye-sensitised photoelectrochemical solar cells with polyacrylonitrile based solid polymer electrolytes

Novel all solid state dye-sensitised photolectrochemical solar cells of the type, FTO-TiO2-dye-PAN, EC, PC, Pr4N+ I-, I-2-Pt-FTO, have been fabricated and characterised using current-voltage characteristics and action spectra. Liquid electrolyte generally used for such solar cells has successfully replaced by a quasi solid electrolyte comprised of polyacrylonitrile (PAN) with ethylene carbonate (EC) and propylene carbonate (PC) as plasticisers and Pr4N+I-/I-2 redox couple with tetrapropylammoniumiodide as the complexing salt. For the polymer electrolyte, the optimum conductivity of 2.95 x 10(-3) S cm(-1) was obtained for the electrolyte composition, PAN:EC:PC = 15:35:50 (wt.%). The short circuit current density (J(SC)) and the open circuit voltage (V-OC) obtained for an incident light intensity of 600 W m(-2) were 3.73 mA cm(-2) and 0.69 V, respectively. This corresponds to an overall quantum efficiency of 2.99%. From the action spectrum, the maximum incident photon conversion efficiency (IPCE) of 33% was obtained for incident light of wavelength 480 nm. (C) 2002 Elsevier Science Ltd. All rights reserved.