Electrophoretic deposition of double-layer ZnO porous films for DSSC photoanode

In this study, via electrophoretic deposition, zinc oxide (ZnO) nanoparticles with different sizes were used to fabricate ZnO photoanode for dye-sensitized solar cells (DSSCs). Results showed that the ZnO layer fabricated by the large-size ZnO particles was better for electron transport and light scattering but unsuitable for dye loading, while the ZnO layer originating from small-size ZnO particles showed contrary results. DSSC devices with single-layer and double-layer ZnO photoanodes were both built. It was found that compared to single-layer ZnO devices, the short-circuit current density of double-layer devices increased up to 34.8% (from 14.09 to 18.99 mA cm −2 ), which is supposedly due to the balance of electron transport and dye loading, as well as the enhancement of light scattering in the double-layer ZnO photoanode. In the optimal DSSC device, the power conversion efficiency with N719 dye achieves 5.87%, which is among the high values in the DSSC device with ZnO photoanode.