Highly efficient PbS/CdS co-sensitized solar cells based on photoanodes with hierarchical pore distribution

A new TiO2 photoanode with hierarchical pore distribution was first employed to fabricate PbS/CdS co-sensitized quantum dot-sensitized solar cell (QDSC). Under AM 1.5 illumination of 100 mW·cm− 2, up to 3.82% of light-to-electricity conversion efficiency has been achieved, higher than the reported results of PbS/CdS QDSCs so far. The effects of PbS SILAR cycles, CdS deposition time and film thickness on cell performance were investigated. Furthermore, comparison between this photoanode with large spherical voids and conventional photoanode with large size TiO2 scattering layer was carried out. This kind of photoanode can provide good scattering ability and large surface area, which is suitable for QDs efficient deposition and electrolyte penetration, exhibiting potential application in highly efficient QDSCs especially with high photocurrent.

► A new photoanodic structure with a hierarchical pore distribution.
► Optimized QD deposition conditions and photoanodic film thickness.
► 3.82% efficiency of PbS/CdS QDSC with a high photocurrent of nearly 20 mA·cm–2.