High stability arc-evaporated carbon counter electrodes in a dye sensitized solar cell based on inorganic and organic redox mediators

Abstract Carbon films were deposited by an arc evaporation method onto conductive glass and applied as counter electrodes in dye sensitized solar cells (DSSCs). Annealing the carbon films in a N 2 atmosphere contributed to the enhancement of DSSC efficiency because their electrocatalytic activities were significantly enhanced. The efficiency of solar cells with carbon films was 2.37% and 2.75% with an I 3 − /I − and T 2 /T − electrolyte, respectively. Whilst, that of DSSCs with annealed carbon was increased to 8.04% using I 3 − /I − and to 4.74% for T 2 /T − . The stability of iodide-based DSSCs was not as high as that of thiolate-based units. Within 50 days, the efficiency of iodide-based DSSC with annealed carbon, Pt and as-deposited carbon dwindled by 20%, 25% and 35%, respectively. After 50 days, the efficiency of DSSCs with annealed carbon employing a disulfide/thiolate electrolyte remained constant, whilst that of DSSCs with as-evaporated carbon and Pt dropped by 26% and 39%, respectively.