Enhancement in dye-sensitized solar cells based on MgO-coated TiO2 electrodes by reactive DC magnetron sputtering

A surface modification method was carried out by reactive DC magnetron sputtering to fabricate TiO2 electrodes coated with insulating MgO for dye-sensitized solar cells. The MgO-coated TiO2 electrode had been characterized by x-ray photoelectron spectroscopy (XPS), energy-dispersive x-ray spectroscopy (EDX), scanning electron microscopy (SEM), UV-vis spectrophotometer, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The study results revealed that the TiO2 modification increases dye adsorption, decreases trap states and suppresses interfacial recombination. The effects of sputtering MgO for different times on the performance of DSSCs were investigated. It indicated that sputtering MgO for 3 min on TiO2 increases all cell parameters, resulting in increasing efficiency from 6.45% to 7.57%.