Raising reproducibility in dye-sensitized solar cells under laboratory conditions

Dye-sensitized solar cells are subject to intensive research nowadays. Their open-circuit voltage, short-circuit current, and efficiency depend on several parameters which can be optimized. Here, examinations are limited to non-toxic substances due to planned future application on textile fabrics, i.e., to TiO₂, graphite, and natural dyes. During experiments on the TiO₂ layer, the reproducibility of the experiment turned out to be a crucial factor, limiting the significance of the experimental findings. Thus, the main goal of this paper is the description of possibilities to standardize the production under laboratory conditions by eliminating distorting factors. Specifically, the pressure by which the glass plates with conductive coatings, serving as electrodes, are pushed together to close the solar cell was found to significantly influence the results. Different possibilities were hence tested to normalize this pressure, including different clamps and magnets. In the optimal setup, the deviations between nominally identical cells could be reduced by one order of magnitude.