Abstract
We demonstrated the effects of Cu 2 O doping at various weight ratios in TiO 2 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% Cu 2 O doping in the photoanode are 690 mV, 4.55 mA/cm2, 52.0%, and 1.96%, respectively. The photovoltaic parameters of the sample with 0.3wt% Cu 2 O doping are better than those of other Cu 2 O-doped samples, which are inferior to undoped TiO 2 - based DSSCs. The measured cell performance shows that the addition of Cu 2 O to the TiO 2 photoanode in DSSCs results in the reduction of photovoltaic parameters. The degradation mechanism upon Cu 2 O doping in the TiO 2 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. © 2012 The Japan Society of Applied Physics.