Effect of Cu2O Doping in TiO2 Films on Device Performance of Dye-Sensitized Solar Cells

Abstract

We demonstrated the effects of Cu2O doping at various weight ratios in TiO2 photoanode films on the photovoltaic performance of dye-sensitized solar cells (DSSCs). The photovoltaic characteristics, namely, open-circuit voltage, short-circuit current, fill factor, and energy conversion efficiency, of DSSCs with 0.3 wt % Cu2O doping in the photoanode are 690 mV, 4.55 mA/cm2, 52.0%, and 1.96%, respectively. The photovoltaic parameters of the sample with 0.3 wt % Cu2O doping are better than those of other Cu2O-doped samples, which are inferior to undoped TiO2-based DSSCs. The measured cell performance shows that the addition of Cu2O to the TiO2 photoanode in DSSCs results in the reduction of photovoltaic parameters. The degradation mechanism upon Cu2O doping in the TiO2 photoanode of DSSCs may be attributed to the variations in the valence numbers of copper and titanium ions during calcination and the reduction–oxidation reaction, resulting in the formation of oxygen vacancy–Ti+3 defects and related recombination centers.