Dye-sensitized solar cells (DSSC): an approach to practice in undergraduate teaching

The aim of this work was to construct and characterize dye-sensitized solar cells (DSSC) using alternative materials and low-cost equipment. Instead of using the TiO₂ semiconductor, a water-based white paint pigment was employed as a substitute. This pigment, when combined with natural dyes, absorbs visible light and acts as the photoelectrode. Pencil graphite was utilized to create the conductive layer, serving as the positive electrode. Lugol's solution was employed as the electrolyte to establish electrical contact between the two electrodes. These materials were assembled between two glasses with a conductive surface made of tin oxide doped with fluorine (FTO glass). Subsequently, the assembled devices were exposed to three types of lamps: daylight (45 W), LED (15 W), and halogen (105 W), all positioned at the same height as the solar cell. Voltage and current measurements were taken using a simple multimeter. These results enabled the correlation of theoretical concepts related to absorption (dye) and light emission (lamp) ranges, different types of anchoring groups, and the dye-semiconductor anchoring mode. The voltage and current production were found to depend on the type of lighting source. However, it became evident that several factors beyond those mentioned strongly influenced the energy production mode of the solar cell. (author)