Enhancing coating uniformity and performance with zinc oxide nanoparticles interface layer in dye-sensitized cells

For over 30 years, dye-sensitized solar cells have been investigated as photovoltaic devices that create a three-dimensional interface among their components. These cells have served as references in exploring new concepts. This study focuses on the impact of a layer of zinc oxide nanoparticles as blocking layers against electron recombination in such solar cells. Various experiments were conducted, including thermal treatments between spin-coating cycles, variations in the number of cycles, and a final thermal treatment. It was observed that the thermal treatment between cycles achieved a more uniform layer and an increase in the open-circuit voltage Voc with each additional cycle. Additionally, cells with nanoparticles showed improvements in the Voc (from 690 to 735 mV) but a reduction in the current density (Jsc) (from 9.5 to 5.5 mA) with more cycles. Those with layers treated at higher temperatures experienced an increase in the Jsc without changing the Voc.