Abstract
Due to low materials cost, ease of production and potential for reasonable power conversion towards commercial applications, dye-sensitized solar cells (DSSCs) are extensively studied as a good replacement to conventional inorganic solar cells. The present study highlights the advancement of new structures in order to further improve their energy conversion efficiency. Therefore, multilayer thin films of ZnO/TiO2 are prepared by a sol-gel spin coating process and annealed at different temperatures 450 degrees C, 550 degrees C and 650 degrees C. In particular, the energy conversion efficiency (solar to electric) of ZnO/TiO2 anodes annealed at 650 degrees C obtained reaches 2.29%, with a fill factor (FF) of 0.73, an open-circuit voltage (V-oc) of 617 mV and a short-circuit current density (J(sc)) of 4.96 mA/cm(2) , that is greater compared to the results achieved at annealing temperatures of 450 degrees C (0.93%) and 550 degrees C (1.12%) respectively. Thus, we observe an improved performance at higher annealing temperatures which is related to an increased film porosity and photoanode surface area, allowing higher amounts of dye to be adsorbed.