Photovoltaic Effect of Metal-Doped TiO2Nanoparticles for Dye-Sensitized Solar Cells

Crystalline anatase TiO 2 nanoparticles (NPs) synthesized by a sol-gel method were used as photoelectrodes in dye-sensitized solar cells (DSSCs). In order to improve the electrochemical properties such as the open circuit voltage ( V oc ) and the rate of electron transfer, various amounts of Al and Zn were doped into TiO 2 NPs. Al doping of TiO 2 NPs successfully improved the photovoltaic performance of the DSSCs as seen in the V oc of 0.79 V for these electrodes. The Zn-doped TiO 2 NPs exhibited faster electron transport than pure TiO 2 or Al-doped TiO 2 NPs. The photovoltaic efficiency ( η ) of pure TiO 2 NPs, 4 mmol Al-doped TiO 2 NPs, and 3 mmol Zn-doped TiO 2 NPs-based DSSCs are 3.90, 5.86, and 5.58%, respectively. In order to improve the V oc , J sc , and electron transfer rates simultaneously, the 4 mmol Al-doped TiO 2 NP and 3 mmol Zn-doped TiO 2 NP powders were mixed together and used for the preparation of photoelectrodes. The η of the mixed Al/Zn-doped TiO 2 NPs-based DSSC was 7.12%, while the V oc , J sc , and electron transport times were 0.75 V, 14.38 mA cm −2 and 3.112 × 10 −4 s, respectively.