The influence of SnO₂ Nanoparticle Conduction Band and the Performance of Dye-sensitized Solar Cells with Al Doping

As a wide band gap, chemical stability, and high electron mobility, SnO₂ is an important alternative to TiO₂ for use as a semiconductor in dye-sensitized solar cells (DSSCs) photoanodes. However, due to its high charge recombination, the energy-conversion efficiency for pure SnO₂-based DSSCs is rather limited so far. In this work, SnO₂ nanocrystals with different proportion Al doping were prepared by simple hydrothermal method. Al-doped SnO₂ photoanodes were fabricated by silk-screen printing. Comparing to pure SnO₂ DSSC, the open-circuit voltage, short circuit current, fill factor of 2% Al-doped SnO₂ photoanode are 0.6 V, 9.61 mA/cm² and 61.08%, respectively, in an AM 1.5 solar simulator. The DSSCs energy conversion efficiency of 2% Al-doped SnO₂ improves from 1.28% to 3.51%. The results show that the Al-doped SnO₂ nanocrystals for DSSCs can adjust SnO₂ conduction band and suppress charge recombination. The energy-conversion efficiency of 2% Al-doped SnO₂ DSSCs effectively is enhanced consequently.