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

Abstract

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 $\left(V_{\mathrm{oc}}\right)$ with each additional cycle. Additionally, cells with nanoparticles showed improvements in the $V_{\mathrm{oc}}$ (from 690 to 735 mV) but a reduction in the current density ${(J}_{\mathrm{sc}})$ (from 9.5 to 5.5 mA) with more cycles. Those with layers treated at higher temperatures experienced an increase in the $J_{\mathrm{sc}}$ without changing the $V_{\mathrm{oc}}$.