Macroporous SnO₂ Synthesized via a Template-Assisted Reflux Process for Efficient Dye-Sensitized Solar Cells

Macroporous SnO2 composed of small SnO2 nanoparticles with diameters around 10 nm is prepared via a reflux process. This novel structure is designed as the photoanode in dye-sensitized solar cells (DSSCs), intending to improve the light utilization efficiency with its excellent light scattering ability. Though the dye adsorption of macroporous SnO2 (14.00 × 10(-8) mol cm(-2)) is lower than that of SnO2 nanoparticles (19.24 × 10(-8) mol cm(-2)), the photovoltaic performance of the DSSCs based on the former is 4.87% compared to 4.41% for SnO2 nanoparticles, showing over 10% increment than the latter. This improvement is mainly due to the enhanced light scattering ability and charge collection efficiency of the macroporous structure, both of which contribute to a higher short current density and hence for the better power conversion efficiency. Furthermore, a double-layer structure composed of SnO2 nanoparticles (active layer) and macroporous SnO2 (scattering layer) possess both large dye adsorption (22.82 × 10(-8) mol cm(-2)) and scattering property, thus leads to a significant overall conversion efficiency of 5.78%.