StSt/TiO2 compact layer/TiO2 triple-layered conducting substrates for large active area dye-sensitized solar cells

Efficient flexible dye-sensitized solar cells (DSSCs) using a stainless steel (StSt) substrate for preparing nanocrystalline TiO2 film electrodes were developed. Large active area (>1 cm2) and SiOx/ITO free StSt DSSCs were fabricated for a systematic investigation. As cell area increased from 1 cm2 (device A) to 4 cm2 (device D) the power conversion efficiency dropped significantly, mostly due to a decrease in the fill factor (FF) and suppression of the short-circuit current density (Jsc). By integrating small-area cells onto StSt substrate to fabricate the large-area DSSC (device C), Rsheet-TCO (sheet resistance of the TCO) can be reduced significantly, yielding the improved performance of the DSSCs. Compared with other methods to prepare StSt-based photoelectrodes, such as sputtering, we provide a simple, low cost and suitable method for the large scale preparation of DSSCs.