Enhanced efficiency of dye-sensitized TiO2 solar cells (DSSC) by doping of metal ions.

Doped TiO(2) semiconductor powders were synthesized using Al and W as photovoltaic property-enhancing impurities. Al-doped TiO(2) electrodes increased open-circuit voltage (V(oc)), but reduced short-circuit current (I(sc)). In contrast, W-doped TiO(2) had an opposite effect. However, dye-sensitized solar cell efficiency fabricated with doped TiO(2) was remarkably better than that of undoped TiO(2). It seems that these phenomena were related to electrical surface-state modifications induced by metal-ion dopants. These modifications led to significant changes in powder aggregation, charge transfer kinetics, and dye adsorption characteristics. The highest efficiency was found by using (Al+W)-doped TiO(2) nanopowders.