Preparation of TiO2/NiO composite particles and their applications in dye-sensitized solar cells

This study investigates the applicability of n-type TiO2 and p-type NiO on the FTO-glass (Fluorine doped tin oxide, SnO2:F) substrate of the working electrode in a dye-sensitized solar cell (DSSC). The working electrode was designed and fabricated by depositing a film of TiO2/NiO composite particles, which were prepared by mixing the Ni powder with TiO2 particles using dry mixing method, on a FTO-glass substrate using a spin coating process. The working electrode was then immersed in the solution of N-719 (Ruthenium) dye at a temperature of 70 °C for 6 h. Moreover, a thin film of platinum (Pt) was deposited on the FTO-glass substrate of the counter electrode using an E-beam evaporator. Finally, the DSSC was assembled, and the short-circuit photocurrent, the open-circuit photovoltage and the power conversion efficiency of DSSC were measured using an I–V measurement system. This study also examined the effects of the mass ratio of TiO2 to Ni and the number of coating of TiO2 particles (or TiO2/NiO composite particles) colloid on the power conversion efficiency of the DSSC. Most importantly, this study shows that the power conversion efficiency of the DSSC with TiO2/NiO composite particles (3.80%) substantially exceeds that of the conventional DSSC (3.27%) due to the effects of the NiO barrier and the n–p junction.