Effect of Natural and Synthetic Dyes on the Performance of Dye-Sensitized Solar Cells Based on ZnO Nanorods Semiconductor

Abstract

The compatibility between natural dyes and semiconductors to produce a good performance of dye-sensitized solar cells plays an important role. The dyes from papaya leaves, mangosteen pericarps, beetroots, and N719 were investigated as sensitizers in the ZnO nanorods-based dye-sensitized solar cells. The ZnO film-coated fluorine-doped tin oxide glass substrates were prepared using a doctor blade method, followed by sintering at 450 °C. Meanwhile, the counter electrode contained of chemically deposited catalytic platinum coating. The working electrodes were first immersed in the N719 dye solution and the respective natural dye solutions at corresponding concentrations of 8 g/100 mL and 21 g/100 mL. The absorptance spectra of the dyes and dye-loaded semiconductor-working electrode were obtained by UV-Vis spectroscopy. In addition, the Fourier transform infrared spectroscopy was used to determine the characteristic functionalities of the dye molecules. Furthermore, N719-based DSSC displayed the highest efficiency (0.47%) whereas papaya leaf-based DSSC achieved the highest efficiency (0.17%) amongst the studied natural dye-based DSSCs. The improved efficiency noted in the natural dye-based DSSC was attributed to the increased current density value. The high absorptance and low electrical resistance of the DSSC loaded with papaya leaf-based dye (concentration: 8 g/100 mL) contributed to the high generated current density value. However, further studies are required to improve the fill factor properties of these solar cells that were < 33%.