Effect of photoanode structure and sensitization conditions on the photovoltaic response of dye-sensitized solar cells

Abstract

This work summarises investigations focused on the photoanode impact on the photovoltaic response of dye-sensitized solar cells. This is a comparison of the results obtained by the authors’ research team with literature data. The studies concern the effect of the chemical structure of the applied dye, TiO2 nanostructure, co-adsorbents addition, and experimental conditions of the anode preparation. The oxide substrates were examined using a scanning electron microscope to determine the thickness and structure of the material. The TiO2 substrates with anchored dye molecules were also tested for absorption properties in the UV-Vis light range, largely translating into current density values. Photovoltaic parameters of the fabricated devices with sandwich structure were obtained from current-voltage measurements. During tests conducted with the N719 dye, it was found that devices containing an 8.4 µm thick oxide semiconductor layer had the highest efficiency (5.99%). At the same time, studies were carried out to determine the effect of the solvent and it was found that the best results were obtained using an ACN : tert-butanol mixture (5.46%). Next, phenothiazine derivatives (PTZ-1–PTZ-6) were used to prepare the devices; among the prepared solar cells, the devices containing PTZ-2 and PTZ-3 had the highest performance (6.21 and 6.22%, respectively). Two compounds designated as Th-1 and M-1 were used to prepare devices containing a dye mixture with N719.